U.S. patent application number 16/286914 was filed with the patent office on 2019-06-27 for nonaqueous electrolyte, capacitor device using same, and carboxylic acid ester compound used in same.
This patent application is currently assigned to UBE INDUSTRIES, LTD.. The applicant listed for this patent is UBE INDUSTRIES, LTD.. Invention is credited to Koji Abe, Kazuhiro Miyoshi, Shoji Shikita, Kei Shimamoto.
Application Number | 20190198928 16/286914 |
Document ID | / |
Family ID | 53402877 |
Filed Date | 2019-06-27 |
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United States Patent
Application |
20190198928 |
Kind Code |
A1 |
Shimamoto; Kei ; et
al. |
June 27, 2019 |
NONAQUEOUS ELECTROLYTE, CAPACITOR DEVICE USING SAME, AND CARBOXYLIC
ACID ESTER COMPOUND USED IN SAME
Abstract
The present invention provides a nonaqueous electrolytic
solution capable of improving electrochemical characteristics in
the case of using an energy storage device at a high temperature
and at a high voltage and further capable of inhibiting the gas
generation while maintaining a capacity retention rate after
storage at a high temperature and at a high voltage and also
provides an energy storage device using the same. Disclosed is a
nonaqueous electrolytic solution having an electrolyte salt
dissolved in a nonaqueous solvent, the nonaqueous electrolytic
solution containing a carboxylic acid ester compound represented by
the following general formula (I). ##STR00001## In the formula,
each of R.sup.1 and R.sup.2 independently represents a hydrogen
atom, a --C(.dbd.O)--OR.sup.4 group, or the like, and R.sup.1 and
R.sup.2 may be bonded to each other to form a ring structure.
R.sup.3 represents a hydrogen atom or the like, and n represents an
integer of 1 to 3. When n is 1, then L and R.sup.4 represent an
alkyl group having 1 to 6 carbon atoms or the like; and when n is 2
or 3, then L represents an n-valent connecting group, X represents
a --C(.dbd.O)-- group, an --S(.dbd.O)-- group, an
--S(.dbd.O).sub.2-- group, an
--S(.dbd.O).sub.2--R.sup.5--S(.dbd.O).sub.2-- group or a
CR.sup.6R.sup.7 group, R.sup.5 represents an alkylene group having
1 to 4 carbon atoms, and each of R.sup.6 and R.sup.7 represents a
hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
Inventors: |
Shimamoto; Kei;
(Shimonoseki-shi, JP) ; Abe; Koji; (Ube-shi,
JP) ; Shikita; Shoji; (Ube-shi, JP) ; Miyoshi;
Kazuhiro; (Ube-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
UBE INDUSTRIES, LTD. |
Ube-shi |
|
JP |
|
|
Assignee: |
UBE INDUSTRIES, LTD.
Ube-shi
JP
|
Family ID: |
53402877 |
Appl. No.: |
16/286914 |
Filed: |
February 27, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15103220 |
Jun 9, 2016 |
10263285 |
|
|
PCT/JP2014/083415 |
Dec 17, 2014 |
|
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16286914 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
Y02T 10/70 20130101;
C07D 327/00 20130101; H01M 2300/0025 20130101; H01G 11/64 20130101;
H01G 11/62 20130101; Y02E 60/13 20130101; H01M 10/4235 20130101;
H01M 10/0567 20130101; Y02T 10/7011 20130101; C07D 317/42 20130101;
Y02T 10/7022 20130101; H01M 10/0568 20130101; C07D 317/36 20130101;
H01M 10/052 20130101; C07D 327/10 20130101 |
International
Class: |
H01M 10/0568 20060101
H01M010/0568; H01G 11/64 20060101 H01G011/64; H01M 10/42 20060101
H01M010/42; C07D 317/36 20060101 C07D317/36; C07D 317/42 20060101
C07D317/42; C07D 327/10 20060101 C07D327/10; C07D 327/00 20060101
C07D327/00; H01M 10/0567 20060101 H01M010/0567; H01M 10/052
20060101 H01M010/052; H01G 11/62 20060101 H01G011/62 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 19, 2013 |
JP |
2013-262928 |
May 23, 2014 |
JP |
2014-107584 |
Sep 4, 2014 |
JP |
2014-179897 |
Claims
1: A nonaqueous electrolytic solution having an electrolyte salt
dissolved in a nonaqueous solvent, the nonaqueous electrolytic
solution comprising from 0.001 to 10% by mass of a carboxylic acid
ester compound represented by the following general formula (I):
##STR00147## wherein: each of R.sup.1 and R.sup.2 independently
represents a hydrogen atom, a halogen atom, an alkyl group having 1
to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms,
an alkenyl group having 2 to 6 carbon atoms, an alkynyl group
having 3 to 6 carbon atoms, an aralkyl group having 7 to 13 carbon
atoms, an aryl group having 6 to 12 carbon atoms, or a
--C(.dbd.O)--OR.sup.4 group, and when R.sup.1 and R.sup.2 are each
an alkyl group, then R.sup.1 and R.sup.2 may be bonded to each
other to form a ring structure; R.sup.3 represents a hydrogen atom,
a halogen atom, or an alkyl group having 1 to 6 carbon atoms; n
represents an integer of 1 to 3; when n is 1, then L and R.sup.4
may be the same as or different from each other and represent an
alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3
to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an
alkynyl group having 3 to 6 carbon atoms, an alkoxyalkyl group
having 2 to 6 carbon atoms, a cyanoalkyl group having 2 to 6 carbon
atoms, an aralkyl group having 7 to 13 carbon atoms, or an aryl
group having 6 to 12 carbon atoms, and when n is 2 or 3, then L
represents an n-valent connecting group constituted of a carbon
atom and a hydrogen atom, which may contain an ether bond, a
thioether bond, or an SO.sub.2 bond and R.sup.4 is the same as
described above; and X represents a --C(.dbd.O)-- group, an
--S(.dbd.O)-- group, an --S(.dbd.O).sub.2-- group, an
--S(.dbd.O).sub.2--R.sup.5--S(.dbd.O).sub.2-- group or a
CR.sup.6R.sup.7 group, R.sup.5 represents an alkylene group having
1 to 4 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom or an alkyl group having 1 to 4
carbon atoms, and each of R.sup.6 and R.sup.7 independently
represents a hydrogen atom or an alkyl group having 1 to 6 carbon
atoms, in which at least one hydrogen atom may be substituted with
a halogen atom, when X is a --C(.dbd.O)-- group, R.sup.1 and/or
R.sup.2 is a --C(.dbd.O)--OR.sup.4 group, and wherein at least one
hydrogen atom of the alkyl group having 1 to 6 carbon atoms, the
cycloalkyl group having 3 to 6 carbon atoms, the alkenyl group
having 2 to 6 carbon atoms, the alkynyl group having 3 to 6 carbon
atoms, the alkoxyalkyl group having 2 to 6 carbon atoms, the
cyanoalkyl group having 2 to 6 carbon atoms, the aralkyl group
having 7 to 13 carbon atoms, or the aryl group having 6 to 12
carbon atoms as R.sup.1, R.sup.2, R.sup.4, or L, may be substituted
with a halogen atom; and further comprising 0.07 to 7% by volume of
one or more selected from vinylene carbonate, vinyl ethylene
carbonate and 4-ethynyl-1,3-dioxolan-2-one, relative to a total
volume of the nonaqueous solvent.
2: The nonaqueous electrolytic solution according to claim 1,
wherein in the general formula (I), X is a --C(.dbd.O)-- group, and
n is an integer of 1 to 3.
3. (canceled)
4: The nonaqueous electrolytic solution according to claim 1,
wherein in the general formula (I), X is an --S(.dbd.O)-- group, an
--S(.dbd.O).sub.2-- group, or a --CR.sup.6R.sup.7 group, and n is
1.
5: The nonaqueous electrolytic solution according to claim 4,
wherein in the general formula (I), the compound wherein X is an
--S(.dbd.O)-- group, an --S(.dbd.O).sub.2-- group, or a
--CR.sup.6R.sup.7 group is a carboxylic acid ester compound
represented by the following general formula (I-2): ##STR00148##
wherein: each of R.sup.21 and R.sup.22 independently represents a
hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon
atoms, in which at least one hydrogen atom may be substituted with
a halogen atom, a cycloalkyl group having 3 to 6 carbon atoms, an
alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 3
to 6 carbon atoms, an aralkyl group having 7 to 13 carbon atoms, in
which at least one hydrogen atom may be substituted with a halogen
atom, an aryl group having 6 to 12 carbon atoms, in which at least
one hydrogen atom may be substituted with a halogen atom, or a
--C(.dbd.O)--OR.sup.25 group, and when R.sup.21 and R.sup.22 are
each an alkyl group, then R.sup.21 and R.sup.22 may be bonded to
each other to form a ring structure; R.sup.23 represents a hydrogen
atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms;
R.sup.24 and R.sup.25 may be the same as or different from each
other and represent an alkyl group having 1 to 6 carbon atoms, in
which at least one hydrogen atom may be substituted with a halogen
atom, a cycloalkyl group having 3 to 6 carbon atoms, in which at
least one hydrogen atom may be substituted with a halogen atom, an
alkenyl group having 2 to 6 carbon atoms, in which at least one
hydrogen atom may be substituted with a halogen atom, an alkynyl
group having 3 to 6 carbon atoms, an alkoxyalkyl group having 2 to
6 carbon atoms, a cyanoalkyl group having 2 to 6 carbon atoms, an
aralkyl group having 7 to 13 carbon atoms, in which at least one
hydrogen atom may be substituted with a halogen atom, or an aryl
group having 6 to 12 carbon atoms, in which at least one hydrogen
atom may be substituted with a halogen atom; and X.sup.1 represents
an --S(.dbd.O) group, an --S(.dbd.O).sub.2 group, or a
--CR.sup.26R.sup.27 group and each of R.sup.26 and R.sup.27
independently represents a hydrogen atom or an alkyl group having 1
to 6 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom.
6: The nonaqueous electrolytic solution according to claim 1,
wherein in the general formula (I), X is an
--S(.dbd.O).sub.2--R.sup.5--S(.dbd.O).sub.2-- group, and n is 1 or
2.
7: The nonaqueous electrolytic solution according to claim 6,
wherein in the general formula (I), the compound wherein X is an
--S(.dbd.O).sub.2--R.sup.5--S(.dbd.O).sub.2-- group, and n is 1 or
2 is a carboxylic acid ester compound represented by the following
general formula (I-3): ##STR00149## wherein: each of R.sup.31 and
R.sup.32 independently represents a hydrogen atom, a halogen atom,
an alkyl group having 1 to 6 carbon atoms, in which at least one
hydrogen atom may be substituted with a halogen atom, an aryl group
having 6 to 12 carbon atoms, in which at least one hydrogen atom
may be substituted with a halogen atom, or a --C(.dbd.O)--OR.sup.34
group; R.sup.33 represents a hydrogen atom, a halogen atom, or an
alkyl group having 1 to 6 carbon atoms; m represents 1 or 2; when m
is 1, then L.sup.3 and R.sup.34 may be the same as or different
from each other and represent an alkyl group having 1 to 6 carbon
atoms, in which at least one hydrogen atom may be substituted with
a halogen atom, a cycloalkyl group having 3 to 6 carbon atoms, in
which at least one hydrogen atom may be substituted with a halogen
atom, an alkenyl group having 2 to 6 carbon atoms, in which at
least one hydrogen atom may be substituted with a halogen atom, an
alkynyl group having 3 to 6 carbon atoms, an alkoxyalkyl group
having 2 to 6 carbon atoms, a cyanoalkyl group having 2 to 6 carbon
atoms, an aralkyl group having 7 to 13 carbon atoms, in which at
least one hydrogen atom may be substituted with a halogen atom, or
an aryl group having 6 to 12 carbon atoms, in which at least one
hydrogen atom may be substituted with a halogen atom, and when m is
2, then L.sup.3 represents an alkylene group having 2 to 8 carbon
atoms, an alkenylene group having 4 to 8 carbon atoms, or an
alkynylene group having 4 to 8 carbon atoms, and at least one
hydrogen atom of L.sup.3 may be substituted with a halogen atom and
R.sup.34 is the same as described above; and X.sup.2 represents an
--S(.dbd.O).sub.2--R.sup.35--S(.dbd.O).sub.2-- group and R.sup.35
represents an alkylene group having 1 to 4 carbon atoms, in which
at least one hydrogen atom may be substituted with a halogen atom
or an alkyl group having 1 to 4 carbon atoms.
8. (canceled)
9: The nonaqueous electrolytic solution according to claim 1,
wherein the nonaqueous electrolytic solution having an electrolyte
salt dissolved in a nonaqueous solvent comprises 0.01 to 5% by mass
of the carboxylic acid ester compound represented by the general
formula (I).
10: The nonaqueous electrolytic solution according to claim 1,
wherein the nonaqueous electrolytic solution having an electrolyte
salt dissolved in a nonaqueous solvent comprises the carboxylic
acid ester compound represented by the general formula (I) and
further comprises LiPF.sub.6 as an electrolyte salt.
11: An energy storage device comprising a positive electrode, a
negative electrode, and a nonaqueous electrolytic solution having
an electrolyte salt dissolved in a nonaqueous solvent, the
nonaqueous electrolytic solution comprising the nonaqueous
electrolytic solution according to claim 1.
12: The energy storage device according to claim 11, wherein the
positive electrode comprises, as a positive electrode active
material, a complex metal oxide containing lithium and one or more
selected from cobalt, manganese, and nickel, or a
lithium-containing olivine-type phosphate.
13: The energy storage device according to claim 11, wherein the
negative electrode comprises, as a negative electrode active
material, one or more selected from lithium metal, a lithium alloy,
a carbon material capable of absorbing and releasing lithium, tin,
a tin compound, silicon, a silicon compound, and a lithium titanate
compound.
14-15. (canceled)
16: The nonaqueous electrolytic solution according to claim 1,
wherein the carboxylic acid ester compound represented by the
formula (I) is at least one selected from 2-propenyl
2-oxo-1,3-dioxolane-4-carboxylate, 2-propynyl
2-oxo-1,3-dioxolane-4-carboxylate, 2-propynyl
5-fluoro-2-oxo-1,3-dioxolane-4-carboxylate, 2-propynyl
4-fluoro-2-oxo-1,3-dioxolane-4-carboxylate, dimethyl
2-oxo-1,3-dioxolane-4,5-dicarboxylate, diethyl
2-oxo-1,3-dioxolane-4,5-dicarboxylate, diisopropyl
2-oxo-1,3-dioxolane-4,5-dicarboxylate, dicyclohexyl
2-oxo-1,3-dioxolane-4,5-dicarboxylate, di(2-propenyl)
2-oxo-1,3-dioxolane-4,5-dicarboxylate, di(2-propynyl)
2-oxo-1,3-dioxolane-4,5-dicarboxylate, di(trifluoroethyl)
2-oxo-1,3-dioxolane-4,5-dicarboxylate, di(tetrafluorophenyl)
2-oxo-1,3-dioxolane-4,5-dicarboxylate, di(pentafluorophenyl)
2-oxo-1,3-dioxolane-4,5-dicarboxylate, 2-butene-1,4-diyl
bis(2-oxo-1,3-dioxolane-4-carboxylate), and 2-butyne-1,4-diyl
bis(2-oxo-1,3-dioxolane-4-carboxylate).
17: The nonaqueous electrolytic solution according to claim 5,
wherein the carboxylic acid ester compound represented by the
formula (I-2) is at least one selected from methyl
1,3,2-dioxathiolane-4-carboxylate 2-oxide, ethyl
1,3,2-dioxathiolane-4-carboxylate 2-oxide, 2-propenyl
1,3,2-dioxathiolane-4-carboxylate 2-oxide, 2-propynyl
1,3,2-dioxathiolane-4-carboxylate 2-oxide, 2,2,2-trifluoroethyl
1,3,2-dioxathiolane-4-carboxylate 2-oxide, methyl
5-fluoro1-1,3,2-dioxathiolane-4-carboxylate 2-oxide, dimethyl
1,3,2-dioxathiolane-4,5-dicarboxylate 2-oxide, diethyl
1,3,2-dioxathiolane-4,5-dicarboxylate 2-oxide, methyl
1,3,2-dioxathiolane-4-carboxylate 2,2-dioxide, ethyl
1,3,2-dioxathiolane-4-carboxylate 2,2-dioxide, 2-propenyl
1,3,2-dioxathiolane-4-carboxylate 2,2-dioxide), 2-propynyl
1,3,2-dioxathiolane-4-carboxylate 2,2-dioxide, 2,2,2-trifluoroethyl
1,3,2-dioxathiolane-4-carboxylate 2,2-dioxide, methyl
5-fluoro-1,3,2-dioxathiolane-4-carboxylate 2,2-dioxide, dimethyl
1,3,2-dioxathiolane-4,5-dicarboxylate 2,2-dioxide, diethyl
1,3,2-dioxathiolane-4,5-dicarboxylate 2,2-dioxide, methyl
1,3-dioxolane-4-carboxylate, ethyl 1,3-dioxolane-4-carboxylate,
2-propenyl 1,3-dioxolane-4-carboxylate, 2-propynyl
1,3-dioxolane-4-carboxylate, 2,2,2-trifluoroethyl
1,3-dioxolane-4-carboxylate, methyl
5-fluoro-1,3-dioxolane-4-carboxylate, dimethyl
1,3-dioxolane-4,5-dicarboxylate, diethyl
1,3-dioxolane-4,5-dicarboxylate, methyl
2,2-dimethyl-1,3-dioxolane-4,5-dicarboxylate and dimethyl
2,2-dimethyl-1,3-dioxolane-4,5-dicarboxylate.
18: The nonaqueous electrolytic solution according to claim 7,
wherein the carboxylic acid ester compound represented by the
formula (I-3) is at least one selected from methyl
1,5,2,4-dioxadithiepane-6-carboxylate 2,2,4,4-tetraoxide, ethyl
1,5,2,4-dioxadithiepane-6-carboxylate 2,2,4,4-tetraoxide,
2-propenyl 1,5,2,4-dioxadithiepane-6-carboxylate
2,2,4,4-tetraoxide, 2-propynyl
1,5,2,4-dioxadithiepane-6-carboxylate 2,2,4,4-tetraoxide,
2,2,2-trifluoroethyl 1,5,2,4-dioxadithiepane-6-carboxylate
2,2,4,4-tetraoxide, methyl
1,5,2,4-dioxadithiepane-7-fluoro-6-carboxylate 2,2,4,4-tetraoxide,
dimethyl 1,5,2,4-dioxadithiepane-6,7-dicarboxylate
2,2,4,4-tetraoxide, and diethyl
1,5,2,4-dioxadithiepane-6,7-dicarboxylate 2,2,4,4-tetraoxide.
Description
TECHNICAL FIELD
[0001] The present invention relates to a nonaqueous electrolytic
solution capable of improving electrochemical characteristics in
using an energy storage device at a high voltage, an energy storage
device using the same, and a carboxylic acid ester compound to be
used for the same.
BACKGROUND ART
[0002] An energy storage device, especially a lithium secondary
battery, has been widely used recently for a power source of a
small-sized electronic device, such as a mobile telephone, a
notebook personal computer, etc., and a power source for an
electric vehicle or electric power storage. With respect to a thin
electronic device, such as a tablet device, an ultrabook, etc., a
laminate-type battery or a prismatic battery using a laminate film,
such as an aluminum laminate film, etc., for an outer packaging
member thereof is frequently used. In such a battery, the outer
packaging member is thin, and therefore, there is involved such a
problem that the battery is easily deformed even by a bit of
expansion of the outer packaging member and the deformation very
likely influences the electronic device.
[0003] A lithium secondary battery is mainly constituted of a
positive electrode and a negative electrode, each containing a
material capable of absorbing and releasing lithium, and a
nonaqueous electrolytic solution including a lithium salt and a
nonaqueous solvent; and a carbonate, such as ethylene carbonate
(EC), propylene carbonate (PC), etc., is used as the nonaqueous
solvent.
[0004] In addition, a lithium metal, a metal compound capable of
absorbing and releasing lithium (e.g., a metal elemental substance,
a metal oxide, an alloy with lithium, etc.), and a carbon material
are known as the negative electrode of the lithium secondary
battery. In particular, a nonaqueous electrolytic solution
secondary battery using, as the carbon material, a carbon material
capable of absorbing and releasing lithium, for example, coke or
graphite (e.g., artificial graphite or natural graphite), etc., is
widely put into practical use.
[0005] Since the aforementioned negative electrode material stores
and releases lithium and an electron at an extremely
electronegative potential equal to the lithium metal, it has a
possibility that a lot of solvents are subjected to reductive
decomposition, and a part of the solvent in the electrolytic
solution is reductively decomposed on the negative electrode
regardless of the kind of the negative electrode material, so that
there were involved such problems that the movement of a lithium
ion is disturbed due to deposition of decomposed products,
generation of a gas, or expansion of the electrode, thereby
worsening battery characteristics, such as cycle properties, etc.,
especially in the case of using the battery at a high temperature
and at a high voltage; and that the battery is deformed due to
expansion of the electrode. Furthermore, it is known that a lithium
secondary battery using a lithium metal or an alloy thereof, a
metal elemental substance, such as tin, silicon, etc., or a metal
oxide thereof as the negative electrode material may have a high
initial battery capacity, but the battery capacity and the battery
performance thereof, such as cycle properties, may be largely
worsened because the micronized powdering of the material may be
promoted during cycles, which brings about accelerated reductive
decomposition of the nonaqueous solvent, as compared with the
negative electrode formed of a carbon material, and the battery may
be deformed due to expansion of the electrode.
[0006] Meanwhile, since a material capable of absorbing and
releasing lithium, which is used as a positive electrode material,
such as LiCoO.sub.2, LiMn.sub.2O.sub.4, LiNiO.sub.2, LiFePO.sub.4,
etc., stores and releases lithium and an electron at an
electropositive voltage of 3.5 V or more on the lithium basis, it
has a possibility that a lot of solvents are subjected to oxidative
decomposition especially in the case of using the battery at a high
temperature and at a high voltage, and a part of the solvent in the
electrolytic solution is oxidatively decomposed on the positive
electrode regardless of the kind of the positive electrode
material, so that there were involved such problems that the
resistance is increased due to deposition of decomposed products;
and that a gas is generated due to decomposition of the solvent,
thereby expanding the battery.
[0007] Under such a situation, in electronic devices having a
lithium secondary battery mounted therein, the electric power
consumption increases, and the capacity increases steadily. The
electrolytic solution is in the environment where the decomposition
is apt to take place more and more due to an increase of
temperature of the battery by the heat generation from the
electronic device, an increase of voltage of charging setting
voltage of the battery, and the like. Thus, there was involved such
a problem that the battery becomes unable to be used due to
expansion of the battery caused by the gas generation, actuation of
a safety mechanism to cut off the current, etc., or the like.
[0008] Irrespective of the foregoing situation, the
multifunctionality of electronic devices on which lithium secondary
batteries are mounted is more and more advanced, and the electric
power consumption tends to increase. The capacity of the lithium
secondary battery is thus being much increased, and because of an
increase of a density of the battery, a reduction of a useless
space capacity within the battery, and so on, a volume occupied by
the nonaqueous electrolytic solution in the battery is becoming
small. In consequence, it is the present situation that in the case
of using the battery at a high temperature and at a high voltage,
the battery performance is apt to be worsened by decomposition of a
bit of the nonaqueous electrolytic solution.
[0009] PTL 1 discloses dihydro-furo[3,4-d]-1,3-dioxole-2,4,6-trione
as one of bicyclo compounds and suggests that when added to an
electrolytic solution, the electrochemical characteristics of the
battery, especially the cycle capacity retention rate at 55.degree.
C., is improved.
[0010] PTL 2 discloses diethyl
2-oxo-1,3-dioxolane-4,5-dicarboxylate having tetraethylammonium
tetrafluoroborate dissolved therein as an electrolytic
solution.
[0011] PTL 3 suggests that when an electrolytic solution containing
methacryloxymethyl ethylene carbonate is used, even in the case of
using high-crystalline carbon for a negative electrode, the
reductive decomposition of the solvent is inhibited, and the
charging and discharging efficiency is improved.
[0012] PTL 4 proposes a nonaqueous electrolytic solution containing
a cyclic sulfuric acid ester, such as an ethylene glycol sulfuric
acid ester, etc., and describes that the decomposition and
deterioration of the electrolytic solution on the electrode surface
are inhibited.
[0013] PTL 5 proposes a nonaqueous electrolytic solution containing
ethylene sulfite and vinylene carbonate and describes that the
25.degree. C. cycle characteristics are improved.
[0014] PTL 6 proposes a nonaqueous electrolytic solution containing
a cyclic ether compound, such as 1,3-dioxane, 1,3-dioxolane, etc.,
and describes that a reaction of a positive electrode with the
electrolytic solution at a high temperature is inhibited, so that
the safety is improved.
[0015] PTL 7 proposes a nonaqueous electrolytic solution containing
1,5,2,4-dioxadithiepane 2,2,4,4-tetraoxide and suggests that the
cycle characteristics and storage characteristics are improved.
[0016] PTL 1: US 2012/0088160A
[0017] PTL 2: JP-A 7-285960
[0018] PTL 3: JP-A 2000-40526
[0019] PTL 4: JP-A 10-189042
[0020] PTL 5: JP-A 11-121032
[0021] PTL 6: JP-A 2014-72050
[0022] PTL 7: JP-A 2004-281368
DISCLOSURE OF INVENTION
Technical Problem
[0023] Problems to be solved by the present invention are to
provide a nonaqueous electrolytic solution capable of improving
electrochemical characteristics in the case of using an energy
storage device at a high temperature and at a high voltage and
further capable of inhibiting the gas generation as well as
improving a capacity retention rate after storage at a high voltage
and at a high temperature, and also to provide an energy storage
device using the same and a carboxylic acid ester compound to be
used for the same.
Solution to Problem
[0024] The present inventors made extensive and intensive
investigations regarding the performance of the nonaqueous
electrolytic solutions of the aforementioned conventional
technologies. As a result, according to the nonaqueous electrolyte
secondary batteries of PTLs 1 and 3, in fact, the effect could not
be substantially exhibited against the problem of inhibiting the
gas generation following charging and discharging in the case of
using an energy storage device at a high temperature and at a high
voltage.
[0025] According to the nonaqueous electrolyte secondary batteries
of PTLs 4 and 5, in fact, the effect could not be substantially
exhibited against the problem of inhibiting the gas generation
following charging and discharging in the case of using an energy
storage device at a high temperature and at a high voltage. In
addition, according to the cyclic ether compound described in PTL
6, though it was perceived to make the gas generation gentle, its
effect was insufficient.
[0026] Even according to the nonaqueous electrolyte secondary
battery of PTL 7, in fact, the effect could not be substantially
exhibited against the problem of inhibiting the gas generation
following charging and discharging in the case of using an energy
storage device at a high temperature and at a high voltage.
[0027] Then, in order to solve the foregoing problems, the present
inventors made extensive and intensive investigations. As a result,
it has been found that by adding a specified carboxylic acid ester
compound, the capacity retention rate after storage in the case of
using an energy storage device at a high temperature and at a high
voltage can be improved, and also, the gas generation can be
inhibited, leading to accomplishment of the present invention.
[0028] Specifically, the present invention provides the following
(1) to (4).
(1) A nonaqueous electrolytic solution having an electrolyte salt
dissolved in a nonaqueous solvent, the nonaqueous electrolytic
solution containing a carboxylic acid ester compound represented by
the following general formula (I).
##STR00002##
[0029] In the formula, each of R.sup.1 and R.sup.2 independently
represents a hydrogen atom, a halogen atom, an alkyl group having 1
to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms,
an alkenyl group having 2 to 6 carbon atoms, an alkynyl group
having 3 to 6 carbon atoms, an aralkyl group having 7 to 13 carbon
atoms, an aryl group having 6 to 12 carbon atoms, or a
--C(.dbd.O)--OR.sup.4 group, and when R.sup.1 and R.sup.2 are each
an alkyl group, then R.sup.1 and R.sup.2 may be bonded to each
other to form a ring structure. R.sup.3 represents a hydrogen atom,
a halogen atom, or an alkyl group having 1 to 6 carbon atoms, and n
represents an integer of 1 to 3.
[0030] When n is 1, then L and R.sup.4 may be the same as or
different from each other and represent an alkyl group having 1 to
6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, an
alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 3
to 6 carbon atoms, an alkoxyalkyl group having 2 to 6 carbon atoms,
a cyanoalkyl group having 2 to 6 carbon atoms, an aralkyl group
having 7 to 13 carbon atoms, or an aryl group having 6 to 12 carbon
atoms, and when n is 2 or 3, then L represents an n-valent
connecting group constituted of a carbon atom and a hydrogen atom,
which may contain an ether bond, a thioether bond, or an SO.sub.2
bond, and R.sup.4 is the same as described above.
[0031] X represents a --C(.dbd.O)-- group, an --S(.dbd.O)-- group,
an --S(.dbd.O).sub.2-- group, an
--S(.dbd.O).sub.2--R.sup.5--S(.dbd.O).sub.2-- group or a
CR.sup.6R.sup.7 group, R.sup.5 represents an alkylene group having
1 to 4 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen group or an alkyl group having 1 to 4
carbon atoms, and each of R.sup.6 and R.sup.7 independently
represents a hydrogen atom or an alkyl group having 1 to 6 carbon
atoms, in which at least one hydrogen atom may be substituted with
a halogen atom.
[0032] At least one hydrogen atom of the alkyl group having 1 to 6
carbon atoms, the cycloalkyl group having 3 to 6 carbon atoms, the
alkenyl group having 2 to 6 carbon atoms, the alkynyl group having
3 to 6 carbon atoms, the alkoxyalkyl group having 2 to 6 carbon
atoms, the cyanoalkyl group having 2 to 6 carbon atoms, the aralkyl
group having 7 to 13 carbon atoms, or the aryl group having 6 to 12
carbon atoms as R.sup.1, R.sup.2, R.sup.4, or L, may be substituted
with a halogen atom.
(2) An energy storage device including a positive electrode, a
negative electrode, and a nonaqueous electrolytic solution having
an electrolyte salt dissolved in a nonaqueous solvent, the
nonaqueous electrolytic solution being the nonaqueous electrolytic
solution as set forth above in (1). (3) A carboxylic acid ester
compound represented by the following general formula (II).
##STR00003##
[0033] In the formula, each of R.sup.41 and R.sup.42 independently
represents a hydrogen atom, a halogen atom, an alkyl group having 1
to 6 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, a cycloalkyl group having 3 to 6
carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an
alkynyl group having 3 to 6 carbon atoms, an aralkyl group having 7
to 13 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, an aryl group having 6 to 12
carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, or a --C(.dbd.O)--OR.sup.44 group,
and when R.sup.41 and R.sup.42 are each an alkyl group, then
R.sup.41 and R.sup.42 may be bonded to each other to form a ring
structure. R.sup.43 represents a hydrogen atom, a halogen atom, or
an alkyl group having 1 to 6 carbon atoms, and m represents 1 or
2.
[0034] When m is 1, then L.sup.4 and R.sup.44 may be the same as or
different from each other and represent a halogenated alkyl group
having 1 to 6 carbon atoms, in which at least one hydrogen atom is
substituted with a halogen atom, a halogenated cycloalkyl group
having 3 to 6 carbon atoms, in which at least one hydrogen atom is
substituted with a halogen atom, an alkenyl group having 2 to 6
carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, an alkynyl group having 3 to 6
carbon atoms, an alkoxyalkyl group having 3 to 6 carbon atoms, a
cyanoalkyl group having 2 to 6 carbon atoms, a halogenated aralkyl
group having 7 to 13 carbon atoms, in which at least one hydrogen
atom is substituted with a halogen atom, or a halogenated aryl
group having 6 to 12 carbon atoms, in which at least one hydrogen
atom is substituted with a halogen atom, and when m is 2, then
L.sup.4 represents an alkylene group having 2 to 6 carbon atoms, in
which at least one hydrogen atom is substituted with a halogen
atom, an alkenylene group having 4 to 8 carbon atoms, or an
alkynylene group having 4 to 8 carbon atoms and R.sup.44 is the
same as described above, provided that when m is 1, then L.sup.4 is
not a 3-methyl-2-buten-1-yl group.
(4) A carboxylic acid ester compound represented by the following
general formula (III).
##STR00004##
[0035] In the formula, each of R.sup.51 and R.sup.52 independently
represents a hydrogen atom, a halogen atom, an alkyl group having 1
to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms,
an alkenyl group having 2 to 6 carbon atoms, an alkynyl group
having 3 to 6 carbon atoms, an aralkyl group having 7 to 13 carbon
atoms, an aryl group having 6 to 12 carbon atoms, or a
--C(.dbd.O)--OR.sup.54 group, and when R.sup.51 and R.sup.52 are
each an alkyl group, then R.sup.51 and R.sup.52 may be bonded to
each other to form a ring structure. R.sup.53 represents a hydrogen
atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms,
and m represents 1 or 2.
[0036] When m is 1, then L.sup.5 and R.sup.54 may be the same as or
different from each other and represent an alkyl group having 1 to
6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, an
alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 3
to 6 carbon atoms, an alkoxyalkyl group having 2 to 6 carbon atoms,
a cyanoalkyl group having 2 to 6 carbon atoms, an aralkyl group
having 7 to 13 carbon atoms, or an aryl group having 6 to 12 carbon
atoms, and when m is 2, then L.sup.5 represents an alkylene group
having 2 to 8 carbon atoms, an alkenylene group having 4 to 8
carbon atoms, or an alkynylene group having 4 to 8 carbon atoms, at
least one hydrogen atom of L.sup.5 may be substituted with a
halogen atom, and R.sup.54 is the same as described above.
[0037] X.sup.3 represents an
--S(.dbd.O).sub.2--R.sup.55--S(.dbd.O).sub.2-- group, and R.sup.55
represents an alkylene group having 1 to 4 carbon atoms, in which
at least one hydrogen atom may be substituted with a halogen atom
or an alkyl group having 1 to 4 carbon atoms.
[0038] At least one hydrogen atom of the alkyl group having 1 to 6
carbon atoms, the cycloalkyl group having 3 to 6 carbon atoms, the
alkenyl group having 2 to 6 carbon atoms, the alkynyl group having
3 to 6 carbon atoms, the alkoxyalkyl group having 2 to 6 carbon
atoms, the cyanoalkyl group having 2 to 6 carbon atoms, the aralkyl
group having 7 to 13 carbon atoms, or the aryl group having 6 to 12
carbon atoms as R.sup.51, R.sup.52, R.sup.54, or L.sup.5, may be
substituted with a halogen atom.
Advantageous Effects of Invention
[0039] According to the present invention, it is possible to
provide a nonaqueous electrolytic solution capable of not only
improving a capacity retention rate after storage but also
inhibiting the gas generation in the case of using an energy
storage device at a high temperature and at a high voltage, and
also to provide an energy storage device, such as a lithium
battery, etc., using the same and a carboxylic acid ester compound
to be used for the same.
DESCRIPTION OF EMBODIMENTS
[0040] The nonaqueous electrolytic solution of the present
invention is concerned with a nonaqueous electrolytic solution
having an electrolyte salt dissolved in a nonaqueous solvent, the
nonaqueous electrolytic solution containing a carboxylic acid ester
compound represented by the following general formula (I).
##STR00005##
[0041] In the formula, R.sup.1, R.sup.2, R.sup.3, X, L, and n are
the same as described above.
[0042] In the nonaqueous electrolytic solution of the present
invention, a content of the carboxylic acid ester compound
represented by the foregoing general formula (I) is preferably
0.001% by mass or more, more preferably 0.01% by mass or more, and
still more preferably 0.3% by mass or more, and preferably 30% by
mass or less, more preferably 20% by mass or less, still more
preferably 10% by mass or less, and yet still more preferably 5% by
mass or less from the viewpoint of forming an appropriate surface
film on an electrode, thereby enhancing an improving effect of
storage characteristics in the case of using a battery at a high
temperature and at a high voltage.
[0043] The nonaqueous electrolytic solution of the present
invention preferably includes the following three embodiments.
Embodiment 11
[0044] Embodiment 1 is an embodiment of using, as the carboxylic
acid ester compound represented by the foregoing general formula
(I), a compound wherein X is a --C(.dbd.O)-- group, and n is an
integer of 1 to 3.
[0045] More specifically, the nonaqueous electrolytic solution
having an electrolyte salt dissolved in a nonaqueous solvent is a
nonaqueous electrolytic solution containing a carboxylic acid ester
compound represented by the following general formula (I-1).
##STR00006##
[0046] In the formula, each of R.sup.11 and R.sup.12 independently
represents a hydrogen atom, a halogen atom, an alkyl group having 1
to 6 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, a cycloalkyl group having 3 to 6
carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an
alkynyl group having 2 to 6 carbon atoms, an aralkyl group having 7
to 13 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, an aryl group having 6 to 12
carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, or a --C(.dbd.O)--OR.sup.14 group,
and when R.sup.11 and R.sup.12 are each an alkyl group, then
R.sup.11 and R.sup.12 may be bonded to each other to form a ring
structure. R.sup.13 represents a hydrogen atom, a halogen atom, or
an alkyl group having 1 to 6 carbon atoms, and n represents an
integer of 1 to 3.
[0047] When n is 1, then L and R.sup.14 may be the same as or
different from each other and represent an alkyl group having 1 to
6 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, a cycloalkyl group having 3 to 6
carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, an alkenyl group having 2 to 6
carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, an alkynyl group having 3 to 6
carbon atoms, an alkoxyalkyl group having 2 to 6 carbon atoms, a
cyanoalkyl group having 2 to 6 carbon atoms, an aralkyl group
having 7 to 13 carbon atoms, in which at least one hydrogen atom
may be substituted with a halogen atom, or an aryl group having 6
to 12 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, and when n is 2 or 3, then L
represents an n-valent connecting group constituted of a carbon
atom and a hydrogen atom, which may contain an ether bond, a
thioether bond, or an SO.sub.2 bond, at least one hydrogen atom of
L may be substituted with a halogen atom, and R.sup.14 is the same
as described above.
Embodiment 2
[0048] Embodiment 2 is an embodiment of using, as the carboxylic
acid ester compound represented by the foregoing general formula
(I), a compound wherein X is an --S(.dbd.O)-- group, an
--S(.dbd.O).sub.2-- group, or a --CR.sup.6R.sup.7 group, and n is
1.
[0049] More specifically, the nonaqueous electrolytic solution
having an electrolyte salt dissolved in a nonaqueous solvent is a
nonaqueous electrolytic solution containing a carboxylic acid ester
compound represented by the following general formula (I-2).
##STR00007##
[0050] In the formula, each of R.sup.21 and R.sup.22 independently
represents a hydrogen atom, a halogen atom, an alkyl group having 1
to 6 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, a cycloalkyl group having 3 to 6
carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an
alkynyl group having 3 to 6 carbon atoms, an aralkyl group having 7
to 13 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, an aryl group having 6 to 12
carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, or a --C(.dbd.O)--OR.sup.25 group,
and when R.sup.21 and R.sup.22 are each an alkyl group, then
R.sup.21 and R.sup.22 may be bonded to each other to form a ring
structure. R.sup.23 represents a hydrogen atom, a halogen atom, or
an alkyl group having 1 to 6 carbon atoms, and R.sup.24 and
R.sup.25 may be the same as or different from each other and
represent an alkyl group having 1 to 6 carbon atoms, in which at
least one hydrogen atom may be substituted with a halogen atom, a
cycloalkyl group having 3 to 6 carbon atoms, in which at least one
hydrogen atom may be substituted with a halogen atom, an alkenyl
group having 2 to 6 carbon atoms, in which at least one hydrogen
atom may be substituted with a halogen atom, an alkynyl group
having 3 to 6 carbon atoms, an alkoxyalkyl group having 2 to 6
carbon atoms, a cyanoalkyl group having 2 to 6 carbon atoms, an
aralkyl group having 7 to 13 carbon atoms, in which at least one
hydrogen atom may be substituted with a halogen atom, or an aryl
group having 6 to 12 carbon atoms, in which at least one hydrogen
atom may be substituted with a halogen atom. X.sup.1 represents an
--S(.dbd.O) group, an --S(.dbd.O).sub.2 group, or a
--CR.sup.26R.sup.27 group and each of R.sup.26 and R.sup.27
independently represents a hydrogen atom or an alkyl group having 1
to 6 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom.
Embodiment 3
[0051] Embodiment 3 is an embodiment of using, as the carboxylic
acid ester compound represented by the foregoing general formula
(I), a compound wherein X is an
--S(.dbd.O).sub.2--R.sup.5--S(.dbd.O).sub.2-- group, and n is 1 or
2.
[0052] More specifically, the nonaqueous electrolytic solution
having an electrolyte salt dissolved in a nonaqueous solvent is a
nonaqueous electrolytic solution containing a carboxylic acid ester
compound represented by the following general formula (I-3).
##STR00008##
[0053] In the formula, each of R.sup.31 and R.sup.32 independently
represents a hydrogen atom, a halogen atom, an alkyl group having 1
to 6 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, an aryl group having 6 to 12
carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, or a --C(.dbd.O)--OR.sup.34 group.
R.sup.33 represents a hydrogen atom, a halogen atom, or an alkyl
group having 1 to 6 carbon atoms, and m represents 1 or 2.
[0054] When m is 1, then L.sup.3 and R.sup.34 may be the same as or
different from each other and represent an alkyl group having 1 to
6 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, a cycloalkyl group having 3 to 6
carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, an alkenyl group having 2 to 6
carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, an alkynyl group having 3 to 6
carbon atoms, an alkoxyalkyl group having 2 to 6 carbon atoms, a
cyanoalkyl group having 2 to 6 carbon atoms, an aralkyl group
having 7 to 13 carbon atoms, in which at least one hydrogen atom
may be substituted with a halogen atom, or an aryl group having 6
to 12 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, and when m is 2, then L.sup.3
represents an alkylene group having 2 to 8 carbon atoms, an
alkenylene group having 4 to 8 carbon atoms, or an alkynylene group
having 4 to 8 carbon atoms, at least one hydrogen atom of L.sup.3
may be substituted with a halogen atom, and R.sup.34 is the same as
described above.
[0055] X.sup.2 represents an
--S(.dbd.O).sub.2--R.sup.35--S(.dbd.O).sub.2-- group, and R.sup.35
represents an alkylene group having 1 to 4 carbon atoms, in which
at least one hydrogen atom may be substituted with a halogen atom
or an alkyl group having 1 to 4 carbon atoms.
[Nonaqueous Electrolytic Solution of Embodiment 1]
[0056] According to the nonaqueous electrolytic solution of
Embodiment 1 of the present invention, in the nonaqueous
electrolytic solution having an electrolyte salt dissolved in a
nonaqueous solvent, the compound represented by the foregoing
general formula (I) wherein X is a --C(.dbd.O)-- group, and n is an
integer of 1 to 3, more specifically the carboxylic acid ester
compound represented by the foregoing general formula (I-1) is
contained in the nonaqueous electrolytic solution.
[0057] Although the reasons why the nonaqueous electrolytic
solution of Embodiment 1 is able to greatly improve the
electrochemical characteristics of an energy storage device when
used at a high temperature and at a high voltage are not always
elucidated yet, the following may be considered.
[0058] In view of the fact that the compound represented by the
general formula (I-1), which is used in Embodiment 1, has a hetero
ring which is reductively decomposed at the .alpha.-position of the
carbonyl group to form a surface film, it has high reactivity and
quickly reacts with active sites of both a positive electrode and a
negative electrode, thereby forming a firmer surface film.
Therefore, it may be considered that not only the storage
characteristics at a high temperature and at a high voltage are
improved, but also the gas generation to be caused due to
decomposition of the solvent is inhibited.
[0059] The carboxylic acid ester compound which is contained in the
nonaqueous electrolytic solution of Embodiment 1 is represented by
the following general formula (I-1).
##STR00009##
[0060] In the formula, each of R.sup.11 and R.sup.12 independently
represents a hydrogen atom, a halogen atom, an alkyl group having 1
to 6 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, a cycloalkyl group having 3 to 6
carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an
alkynyl group having 2 to 6 carbon atoms, an aralkyl group having 7
to 13 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, an aryl group having 6 to 12
carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, or a --C(.dbd.O)--OR.sup.14 group,
and when R.sup.11 and R.sup.12 are each an alkyl group, then
R.sup.11 and R.sup.12 may be bonded to each other to form a ring
structure. R.sup.13 represents a hydrogen atom, a halogen atom, or
an alkyl group having 1 to 6 carbon atoms, and n represents an
integer of 1 to 3.
[0061] When n is 1, then L and R.sup.14 may be the same as or
different from each other and represent an alkyl group having 1 to
6 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, a cycloalkyl group having 3 to 6
carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, an alkenyl group having 2 to 6
carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, an alkynyl group having 3 to 6
carbon atoms, an alkoxyalkyl group having 2 to 6 carbon atoms, a
cyanoalkyl group having 2 to 6 carbon atoms, an aralkyl group
having 7 to 13 carbon atoms, in which at least one hydrogen atom
may be substituted with a halogen atom, or an aryl group having 6
to 12 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, and when n is 2 or 3, then L
represents an n-valent connecting group constituted of a carbon
atom and a hydrogen atom, which may contain an ether bond, a
thioether bond, or an SO.sub.2 bond, at least one hydrogen atom of
L may be substituted with a halogen atom, and R.sup.14 is the same
as described above.
[0062] In the foregoing general formula (I-1), each of R.sup.11 and
R.sup.12 is independently preferably a hydrogen atom, a halogen
atom, an alkyl group having 1 to 6 carbon atoms, in which at least
one hydrogen atom may be substituted with a halogen atom, a
cycloalkyl group having 3 to 6 carbon atoms, an alkenyl group
having 2 to 6 carbon atoms, an alkynyl group having 3 to 6 carbon
atoms, or a --C(.dbd.O)--OR.sup.14 group, and more preferably a
hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon
atoms, in which at least one hydrogen atom may be substituted with
a halogen atom, or a --C(.dbd.O)--OR.sup.14 group. When R.sup.1 and
R.sup.12 are each an alkyl group, then R.sup.11 and R.sup.12 may be
bonded to each other to form a ring structure.
[0063] R.sup.13 is preferably a hydrogen atom or a halogen atom,
and more preferably a hydrogen atom. n is preferably 1 or 2, and
more preferably 1.
[0064] When n is 1, then L and R.sup.14 may be the same as or
different from each other and are preferably an alkyl group having
1 to 6 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, a cycloalkyl group having 3 to 6
carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, an alkenyl group having 2 to 6
carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, an alkynyl group having 3 to 6
carbon atoms, or an aryl group having 6 to 12 carbon atoms, in
which at least one hydrogen atom may be substituted with a halogen
atom, and more preferably an alkenyl group having 2 to 6 carbon
atoms or an alkynyl group having 3 to 6 carbon atoms.
[0065] As specific examples of R.sup.11 and R.sup.12, there are
suitably exemplified a hydrogen atom; a halogen atom, such as a
fluorine atom, a chlorine atom, a bromine atom, etc.; a
straight-chain alkyl group, such as a methyl group, an ethyl group,
an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl
group, etc.; a branched alkyl group, such as an isopropyl group, a
sec-butyl group, a 2-pentyl group, a 3-pentyl group, a tert-butyl
group, a tert-amyl group, etc.; a halogenated alkyl group, such as
a fluoromethyl group, a difluoromethyl group, a trifluoromethyl
group, a 2-chloroethyl group, a 2-fluoroethyl group, a
2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, a
3-fluoropropyl group, a 3-chloropropyl group, a 3,3-difluoropropyl
group, a 3,3,3-trifluoropropyl group, a 2,2,3,3-tetrafluoropropyl
group, a 2,2,3,3,3-pentafluoropropyl group, etc.; a cycloalkyl
group, such as a cyclopropyl group, a cyclobutyl group, a
cyclopentyl group, a cyclohexyl group, a cycloheptyl group, etc.;
an alkenyl group, such as vinyl group, a 1-propen-1-yl group, a
2-propen-1-yl group, a 2-buten-1-yl group, a 3-buten-1-yl group, a
4-penten-1-yl group, a 5-hexen-1-yl group, a 1-propen-2-yl group, a
1-buten-2-yl group, a 2-methyl-2-propen-1-yl group, etc.; an
alkynyl group, such as an ethynyl group, a 2-propynyl group, a
2-butynyl group, a 3-butynyl group, a 4-heptynyl group, a
1-methyl-2-propynyl group, a 1,1-dimethyl-2-propynyl group, a
1-methyl-3-butynyl group, a 1-methyl-4-heptynyl group, etc.; an
aralkyl group, such as a benzyl group, a 4-methylbenzyl group, a
4-tert-butylbenzyl group, a 4-fluorobenzyl group, a 4-chlorobenzyl
group, a 1-phenylethan-1-yl group, a 2-phenylethan-1-yl group, a
3-phenylpropan-1-yl group, etc.; and an aryl group, such as a
phenyl group, a 2-methylphenyl group, a 3-methylphenyl group, a
4-methylphenyl group, a 4-tert-butylphenyl group, a 2-fluorophenyl
group, a 4-fluorophenyl group, a 2-trifluoromethylphenyl group, a
3-trifluoromethylphenyl group, a 4-trifluoromethylphenyl group, a
4-fluoro-2-trifluoromethylphenyl group, a
4-fluoro-3-trifluoromethylphenyl group, a 2,6-difluorophenyl group,
a 3,5-difluorophenyl group, a 2,4,6-trifluorophenyl group, a
2,3,5,6-tetrafluorophenyl group, a perfluorophenyl group, etc.; and
also a methoxycarbonyl group, an ethoxycarbonyl group, a
2,2,2-trifluoroethoxycarbonyl group, a
2,2,3,3-tetrafluoropropoxycarbonyl group, a cyclopentyloxycarbonyl
group, a cyclohexyloxycarbonyl group, a vinyloxycarbonyl group, a
1-propen-1-yloxycarbonyl group, a 2-propen-1-yloxycarbonyl group, a
2-propynyloxycarbonyl group, a 1-methyl-2-propynyloxycarbonyl
group, a benzyloxycarbonyl group, a phenyloxycarbonyl group, a
4-fluorophenyloxycarbonyl group, a
2-trifluoromethylphenyloxycarbonyl group, a
4-fluoro-3-trifluoromethylphenyloxycarbonyl group, a
2,3,5,6-tetrafluorophenyloxycarbonyl group, a
perfluorophenyloxycarbonyl group, and the like.
[0066] Of the foregoing, R.sup.11 and R.sup.12 are preferably a
hydrogen atom, a fluorine atom, a chlorine atom, a methyl group, an
ethyl group, an n-propyl group, an n-butyl group, an n-pentyl
group, an n-hexyl group, an isopropyl group, a sec-butyl group, a
tert-butyl group, a trifluoromethyl group, a 2,2,2-trifluoroethyl
group, a 2,2,3,3-tetrafluoropropyl group, a cyclopentyl group, a
cyclohexyl group, a vinyl group, a 1-propen-1-yl group, a
2-propen-1-yl group, a 2-buten-1-yl group, a 1-propen-2-yl group, a
2-methyl-2-propen-1-yl group, an ethynyl group, a 2-propynyl group,
a 1-methyl-2-propynyl group, a methoxycarbonyl group, an
ethoxycarbonyl group, a 2,2,2-trifluoroethoxycarbonyl group, a
2,2,3,3-tetrafluoropropoxycarbonyl group, a vinyloxycarbonyl group,
a 1-propen-1-yloxycarbonyl group, a 2-propen-1-yloxycarbonyl group,
a 2-propynyloxycarbonyl group, a 1-methyl-2-propynyloxycarbonyl
group, a phenyloxycarbonyl group, a
2-trifluoromethylphenyloxycarbonyl group, a
4-fluoro-3-trifluoromethylphenyloxycarbonyl group, a
2,3,5,6-tetrafluorophenyloxycarbonyl group, or a
perfluorophenyloxycarbonyl group; and more preferably a hydrogen
atom, a fluorine atom, a methyl group, an ethyl group, a
trifluoromethyl group, a 2-propen-1-yloxycarbonyl group, or a
2-propenyloxycarbonyl group.
[0067] When R.sup.11 and R.sup.12 are each an alkyl group, then
R.sup.11 and R.sup.12 may be bonded to each other to form a ring
structure. As specific examples thereof, there are suitably
exemplified an ethane-1,2-diyl group, a propane-1,3-diyl group, a
butane-1,4-diyl group, and a pentane-1,5-diyl group, with a
butane-1,4-diyl group or a pentane-1,5-diyl group being
preferred.
[0068] As specific examples of R.sup.13, there are suitably
exemplified a hydrogen atom; a halogen atom, such as a fluorine
atom, a chlorine atom, a bromine atom, etc.; a straight-chain alkyl
group, such as a methyl group, an ethyl group, an n-propyl group,
an n-butyl group, an n-pentyl group, an n-hexyl group, etc.; and a
branched alkyl group, such as an isopropyl group, a sec-butyl
group, a 2-pentyl group, a pentan-3-yl group, a tert-butyl group, a
tert-amyl group, etc. Above all, a hydrogen atom, a fluorine atom,
a chlorine atom, a methyl group, an ethyl group, an n-propyl group,
an n-butyl group, an isopropyl group, a sec-butyl group, or a
tert-butyl group is preferred, with a hydrogen atom, a fluorine
atom, a methyl group, or an ethyl group being more preferred.
[0069] As specific examples of L, there are suitably exemplified
the following groups.
(i) In the case of n=1:
[0070] There are suitably exemplified a straight-chain alkyl group,
such as a methyl group, an ethyl group, an n-propyl group, an
n-butyl group, an n-pentyl group, an n-hexyl group, etc.; a
branched alkyl group, such as an isopropyl group, a sec-butyl
group, a 2-pentyl group, a 3-pentyl group, a tert-butyl group, a
tert-amyl group, etc.; a halogenated alkyl group, such as a
fluoromethyl group, a difluoromethyl group, a 2-chloroethyl group,
a 2-fluoroethyl group, a 2,2-difluoroethyl group, a
2,2,2-trifluoroethyl group, a 3-fluoropropyl group, a
3-chloropropyl group, a 3,3-difluoropropyl group, a
3,3,3-trifluoropropyl group, a 2,2,3,3-tetrafluoropropyl group, a
2,2,3,3,3-pentafluoropropyl group, etc.; a cycloalkyl group, such
as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a
cyclohexyl group, a cycloheptyl group, etc.; a halogenated
cycloalkyl group, such as a 4-fluorocyclohexyl group, a
4-chlorocyclohexyl group, etc.; an alkenyl group, such as a vinyl
group, a 1-propen-1-yl group, a 2-propen-1-yl group, a 2-buten-1-yl
group, a 3-buten-1-yl group, a 4-penten-1-yl group, a 5-hexen-1-yl
group, a 1-propen-2-yl group, a 1-buten-2-yl group, a
2-methyl-2-propen-1-yl group, etc.; a haloalkenyl group, such as a
3,3-difluoro-2-propen-1-yl group, a 4,4-difluoro-3-buten-1-yl
group, a 3,3-dichloro-2-propen-1-yl group, a
4,4-dichloro-3-buten-1-yl group, etc.; an alkynyl group, such as a
2-propynyl group, a 2-butynyl group, a 3-butynyl group, a
4-heptynyl group, a 1-methyl-2-propynyl group, a
1,1-dimethyl-2-propynyl group, a 1-methyl-3-butynyl group, a
1-methyl-4-heptynyl group, etc.; an alkoxyalkyl group, such as a
methoxymethyl group, an ethoxymethyl group, a methoxyethyl group,
an ethoxyethyl group, an n-propoxyethyl group, an n-butoxyethyl
group, a methoxypropyl group, an ethoxypropyl group, etc.; an
aralkyl group, such as a benzyl group, a 4-methylbenzyl group, a
4-tert-butylbenzyl group, a 4-fluorobenzyl group, a 4-chlorobenzyl
group, a 1-phenylethan-1-yl group, a 2-phenylethan-1-yl group, a
3-phenylpropan-1-yl group, etc.; an aryl group, such as a phenyl
group, a 2-methylphenyl group, a 3-methylphenyl group, a
4-methylphenyl group, a 4-tert-butylphenyl group, a 2-fluorophenyl
group, a 4-fluorophenyl group, a 2-trifluoromethylphenyl group, a
3-trifluoromethylphenyl group, a 4-trifluoromethylphenyl group, a
4-fluoro-2-trifluoromethylphenyl group, a
4-fluoro-3-trifluoromethylphenyl group, a 2,6-difluorophenyl group,
a 3,5-difluorophenyl group, a 2,4,6-trifluorophenyl group, a
2,3,5,6-tetrafluorophenyl group, a perfluorophenyl group, etc.; and
the like.
[0071] In the case of n=1, of the foregoing, L is preferably a
methyl group, an ethyl group, an n-propyl group, an n-butyl group,
an isopropyl group, a sec-butyl group, a 2,2,2-trifluoroethyl
group, a 2,2,3,3-tetrafluoropropyl group, a cyclopropyl group, a
cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a vinyl
group, a 1-propen-1-yl group, a 2-propen-1-yl group, a 2-buten-1-yl
group, a 3-buten-1-yl group, a 1-propen-2-yl group, a 1-buten-2-yl
group, a 2-methyl-2-propen-1-yl group, a 3,3-difluoro-2-propen-1-yl
group, a 4,4-difluoro-3-buten-1-yl group, a
3,3-dichloro-2-propen-1-yl group, a 4,4-dichloro-3-buten-1-yl
group, a 2-propynyl group, a 2-butynyl group, a 3-butynyl group, a
1-methyl-2-propynyl group, a 1,1-dimethyl-2-propynyl group, a
2,3,5,6-tetrafluorophenyl group, or a perfluorophenyl group; and
more preferably a vinyl group, a 1-propen-1-yl group, a
2-propen-1-yl group, a 2-buten-1-yl group, a 1-propen-2-yl group, a
3,3-difluoro-2-propen-1-yl group, a 4,4-difluoro-3-buten-1-yl
group, a 2-propynyl group, a 2-butynyl group, a 3-butynyl group, or
a 1-methyl-2-propynyl group.
(ii) In the case of n=2:
[0072] There are suitably exemplified a straight-chain alkylene
group, such as an ethylene group, a propane-1,3-diyl group, a
butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl
group, etc.; a branched alkylene group, such as a propane-1,2-diyl
group, a butane-1,3-diyl group, a butane-2,3-diyl group, a
2-methylpropane-1,2-diyl group, a 2,2-dimethylpropane-1,3-diyl
group, etc.; a haloalkylene group, such as a
2,2-difluoropropane-1,3-diyl group, a
2,2,3,3-tetrafluorobutane-1,4-diyl group, a
2,2,3,3,4,4-hexafluoropentane-1,5-diyl group, a
2,2,3,3,4,4,5,5-octafluorohexane-1,6-diyl group, a
2,2-dichloropropane-1,3-diyl group, a
2,2,3,3-tetrachlorobutene-1,4-diyl group, etc.; an alkenylene
group, such as a 2-butene-1,4-diyl group, a 2-pentene-1,5-diyl
group, a 3-hexene-1,6-diyl group, a 3-hexene-2,5-diyl group, a
2,5-dimethyl-3-hexene-2,5-diyl group, etc.; an alkynylene group,
such as a 2-butyne-1,4-diyl group, a 2-pentyne-1,5-diyl group, a
3-hexyne-1,6-diyl group, a 3-hexyne-2,5-diyl group, a
2,5-dimethyl-3-hexyne-2,5-diyl group, etc.; a cycloalkylene group,
such as a cyclopentane-1,2-diyl group, a cyclopentane-1,3-diyl
group, a cyclohexane-1,2-diyl group, a cyclohexane-1,3-diyl group,
a cycloheptane-1,3-diyl group, a cyclohexane-1,4-diyl group, a
cycloheptane-1,4-diyl group, etc.; a connecting group having an
ether group, such as --CH.sub.2CH.sub.2OCH.sub.2CH.sub.2--,
--CH.sub.2CH.sub.2OCH.sub.2CH.sub.2OCH.sub.2CH.sub.2--,
--CH.sub.2CH.sub.2CH.sub.2OCH.sub.2CH.sub.2CH.sub.2--,
--CH(CH.sub.3)CH.sub.2OCH.sub.2CH(CH.sub.3)--, etc.; a connecting
group having a thioether bond, such as
--CH.sub.2CH.sub.2SCH.sub.2CH.sub.2--,
--CH.sub.2CH.sub.2CH.sub.2SCH.sub.2CH.sub.2CH.sub.2--, etc.; a
connecting group having an S(.dbd.O).sub.2 bond, such as
--CH.sub.2CH.sub.2S(.dbd.O).sub.2CH.sub.2CH.sub.2--,
--CH.sub.2CH.sub.2CH.sub.2S(.dbd.O).sub.2CH.sub.2CH.sub.2CH.sub.2--,
etc.; and an aromatic connecting group, such as a benzene-1,2-diyl
group, a benzene-1,3-diyl group, a benzene-1,4-diyl group, etc.
[0073] In the case of n=2, of the foregoing, L is preferably an
ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group,
a pentane-1,5-diyl group, a hexane-1,6-diyl group, a
propane-1,2-diyl group, a butane-2,3-diyl group, a
2,2-dimethylpropane-1,3-diyl group, a 2-butene-1,4-diyl group, a
3-hexene-2,5-diyl group, a 2-butyne-1,4-diyl group, a
3-hexyne-2,5-diyl group, a cyclohexane-1,2-diyl group, a
cyclohexane-1,4-diyl group, a cycloheptane-1,2-diyl group,
--CH.sub.2CH.sub.2OCH.sub.2CH.sub.2--,
--CH.sub.2CH.sub.2S(.dbd.O).sub.2CH.sub.2CH.sub.2--, or a
benzene-1,4-diyl group, and more preferably a 2-butene-1,4-diyl
group or a 2-butyne-1,4-diyl group.
(iii) In the case of n=3:
[0074] There are suitably exemplified groups having the following
structures. ("*" in the following structures represents a bonding
site.)
##STR00010##
[0075] As the compound represented by the foregoing general formula
(I-1), specifically, there are suitably exemplified the following
compounds.
##STR00011## ##STR00012## ##STR00013## ##STR00014## ##STR00015##
##STR00016## ##STR00017## ##STR00018## ##STR00019## ##STR00020##
##STR00021## ##STR00022## ##STR00023## ##STR00024## ##STR00025##
##STR00026## ##STR00027## ##STR00028## ##STR00029## ##STR00030##
##STR00031## ##STR00032## ##STR00033## ##STR00034## ##STR00035##
##STR00036##
[0076] Among the aforementioned compounds, as the compound
represented by the general formula (I-1), the compounds having any
one of the structural formulae of 1 to 4, 6, 7, 12 to 15, 19 to 23,
26, 27, 29 to 31, 33, 34, 41, 42, 46 to 49, 81, 82, 84, 85, 88, 89,
112, 115 to 131, 133 to 136, 138, 140 to 143, 146, 147, and 148 are
more preferred; the compounds having any one of the structural
formulae of 19 to 21, 26, 29, 30, 33, 46, 47, 81, 82, 84, 85, 88,
115 to 118, 123, 124, and 140 to 143 are still more preferred; and
2-propenyl 2-oxo-1,3-dioxolane-4-carboxylate (structural formula
21), 2-propynyl 2-oxo-1,3-dioxolane-4-carboxylate (structural
formula 29), 2-propynyl 5-fluoro-2-oxo-1,3-dioxolane-4-carboxylate
(structural formula 116), 2-propynyl
4-fluoro-2-oxo-1,3-dioxolane-4-carboxylate (structural formula
118), di(2-propenyl) 2-oxo-1,3-dioxolane-4,5-dicarboxylate
(structural formula 123), di(2-propynyl)
2-oxo-1,3-dioxolane-4,5-dicarboxylate (structural formula 124),
2-butene-1,4-diyl bis(2-oxo-1,3-dioxolane-4-carboxylate)
(structural formula 140), and 2-butyne-1,4-diyl
bis(2-oxo-1,3-dioxolane-4-carboxylate) (structural formula 142) are
especially preferred.
[0077] In the nonaqueous electrolytic solution of the present
invention, a content of the carboxylic acid ester compound
represented by the foregoing general formula (I-1) is preferably
0.001 to 30% by mass in the nonaqueous electrolytic solution. So
long as the content is 30% by mass or less, there is less concern
that a surface film is excessively formed on an electrode, so that
in the case of using a battery at a high temperature and at a high
voltage, the storage characteristics are worsened. So long as the
content is 0.001% by mass or more, the formation of a surface film
is sufficient, and in the case of using a battery at a high
temperature and at a high voltage, an improving effect of the
storage characteristics is enhanced. The content is preferably
0.01% by mass or more, and more preferably 0.3% by mass or more in
the nonaqueous electrolytic solution. An upper limit thereof is
preferably 20% by mass or less, more preferably 10% by mass or
less, and especially preferably 5% by mass or less.
[Nonaqueous Electrolytic Solution of Embodiment 2]
[0078] According to the nonaqueous electrolytic solution of
Embodiment 2 of the present invention, in the nonaqueous
electrolytic solution having an electrolyte salt dissolved in a
nonaqueous solvent, the compound represented by the foregoing
general formula (I) wherein X is an --S(.dbd.O)-- group, an
--S(.dbd.O).sub.2-- group, or a --CR.sup.6R.sup.7 group, and n is
1, more specifically the carboxylic acid ester compound represented
by the foregoing general formula (I-2) is contained in the
nonaqueous electrolytic solution.
[0079] Although the reasons why the nonaqueous electrolytic
solution of Embodiment 2 is able to greatly improve the
electrochemical characteristics of an energy storage device when
used at a high temperature and at a high voltage are not always
elucidated yet, the following may be considered.
[0080] The compound represented by the general formula (I-2), which
is used in Embodiment 2, has an --S(.dbd.O)-- group, an
--S(.dbd.O).sub.2-- group, or a --CR.sup.6R.sup.7 group and at
least one carboxylic acid ester group that is an electron
attractive group. For this reason, as compared with the compounds
not having a carboxylic acid ester group but having only the ring
structure as described in PTLs 4 to 6, it may be considered that
the reactivity on the electrode becomes much higher, the compound
represented by the general formula (I-2) quickly reacts with active
sites of both the positive electrode and the negative electrode.
Furthermore, it may be considered that in view of the fact that the
carboxylic acid ester is contained in the surface film, the
compound forms a firmer surface film, improves the storage
characteristics at a high temperature and at a high voltage, and
inhibits the gas generation to de caused due to decomposition of
the solvent.
[0081] The carboxylic acid ester compound which is contained in the
nonaqueous electrolytic solution of Embodiment 2 is represented by
the following general formula (I-2).
##STR00037##
[0082] In the formula, each of R.sup.21 and R.sup.22 independently
represents a hydrogen atom, a halogen atom, an alkyl group having 1
to 6 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, a cycloalkyl group having 3 to 6
carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an
alkynyl group having 3 to 6 carbon atoms, an aralkyl group having 7
to 13 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, an aryl group having 6 to 12
carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, or a --C(.dbd.O)--OR.sup.25 group,
and when R.sup.21 and R.sup.22 are each an alkyl group, then
R.sup.21 and R.sup.22 may be bonded to each other to form a ring
structure. R.sup.23 represents a hydrogen atom, a halogen atom, or
an alkyl group having 1 to 6 carbon atoms, and R.sup.24 and
R.sup.25 may be the same as or different from each other and
represent an alkyl group having 1 to 6 carbon atoms, in which at
least one hydrogen atom may be substituted with a halogen atom, a
cycloalkyl group having 3 to 6 carbon atoms, in which at least one
hydrogen atom may be substituted with a halogen atom, an alkenyl
group having 2 to 6 carbon atoms, in which at least one hydrogen
atom may be substituted with a halogen atom, an alkynyl group
having 3 to 6 carbon atoms, an alkoxyalkyl group having 2 to 6
carbon atoms, a cyanoalkyl group having 2 to 6 carbon atoms, an
aralkyl group having 7 to 13 carbon atoms, in which at least one
hydrogen atom may be substituted with a halogen atom, or an aryl
group having 6 to 12 carbon atoms, in which at least one hydrogen
atom may be substituted with a halogen atom. X.sup.1 represents an
--S(.dbd.O) group, an --S(.dbd.O).sub.2 group, or a
--CR.sup.26R.sup.27 group, and each of R.sup.26 and R.sup.27
independently represents a hydrogen atom or an alkyl group having 1
to 6 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom.
[0083] As specific examples of R.sup.21 and R.sup.22, there are
suitably exemplified a hydrogen atom; a halogen atom, such as a
fluorine atom, a chlorine atom, a bromine atom, etc.; a
straight-chain alkyl group, such as a methyl group, an ethyl group,
an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl
group, etc.; a branched alkyl group, such as an isopropyl group, a
sec-butyl group, a 2-pentyl group, a 3-pentyl group, a tert-butyl
group, a tert-amyl group, etc.; a halogenated alkyl group, such as
a fluoromethyl group, a difluoromethyl group, a trifluoromethyl
group, a 2-chloroethyl group, a 2-fluoroethyl group, a
2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, a
3-fluoropropyl group, a 3-chloropropyl group, a 3,3-difluoropropyl
group, a 3,3,3-trifluoropropyl group, a 2,2,3,3-tetrafluoropropyl
group, a 2,2,3,3,3-pentafluoropropyl group, etc.; a cycloalkyl
group, such as a cyclopropyl group, a cyclobutyl group, a
cyclopentyl group, a cyclohexyl group, a cycloheptyl group, etc.;
an alkenyl group, such as vinyl group, a 1-propen-1-yl group, a
2-propen-1-yl group, a 2-buten-1-yl group, a 3-buten-1-yl group, a
4-penten-1-yl group, a 5-hexen-1-yl group, a 1-propen-2-yl group, a
1-buten-2-yl group, a 2-methyl-2-propen-1-yl group, etc.; an
alkynyl group, such as an ethynyl group, a 2-propynyl group, a
2-butynyl group, a 3-butynyl group, a 4-heptynyl group, a
1-methyl-2-propynyl group, a 1,1-dimethyl-2-propynyl group, a
1-methyl-3-butynyl group, a 1-methyl-4-heptynyl group, etc.; an
aralkyl group, such as a benzyl group, a 4-methylbenzyl group, a
4-tert-butylbenzyl group, a 4-fluorobenzyl group, a 4-chlorobenzyl
group, a 1-phenylethan-1-yl group, a 2-phenylethan-1-yl group, a
3-phenylpropan-1-yl group, etc.; and an aryl group, such as a
phenyl group, a 2-methylphenyl group, a 3-methylphenyl group, a
4-methylphenyl group, a 4-tert-butylphenyl group, a 2-fluorophenyl
group, a 4-fluorophenyl group, a 2-trifluoromethylphenyl group, a
3-trifluoromethylphenyl group, a 4-trifluoromethylphenyl group, a
4-fluoro-2-trifluoromethylphenyl group, a
4-fluoro-3-trifluoromethylphenyl group, a 2,6-difluorophenyl group,
a 3,5-difluorophenyl group, a 2,4,6-trifluorophenyl group, a
2,3,5,6-tetrafluorophenyl group, a perfluorophenyl group, etc.; and
also a methoxycarbonyl group, an ethoxycarbonyl group, a
2,2,2-trifluoroethoxycarbonyl group, a
2,2,3,3-tetrafluoropropoxycarbonyl group, a cyclopentyloxycarbonyl
group, a cyclohexyloxycarbonyl group, a vinyloxycarbonyl group, a
1-propen-1-yloxycarbonyl group, a 2-propen-1-yloxycarbonyl group, a
2-propynyloxycarbonyl group, a 1-methyl-2-propynyloxycarbonyl
group, a benzyloxycarbonyl group, a phenyloxycarbonyl group, a
4-fluorophenyloxycarbonyl group, a
2-trifluoromethylphenyloxycarbonyl group, a
4-fluoro-3-trifluoromethylphenyloxycarbonyl group, a
2,3,5,6-tetrafluorophenyloxycarbonyl group, a
perfluorophenyloxycarbonyl group, and the like.
[0084] Of the foregoing, R.sup.21 and R.sup.22 are preferably a
hydrogen atom, a fluorine atom, a chlorine atom, a methyl group, an
ethyl group, an n-propyl group, an n-butyl group, an n-pentyl
group, an n-hexyl group, an isopropyl group, a sec-butyl group, a
tert-butyl group, a trifluoromethyl group, a 2,2,2-trifluoroethyl
group, a 2,2,3,3-tetrafluoropropyl group, a cyclopentyl group, a
cyclohexyl group, a vinyl group, a 1-propen-1-yl group, a
2-propen-1-yl group, a 2-buten-1-yl group, a 1-propen-2-yl group, a
2-methyl-2-propen-1-yl group, an ethynyl group, a 2-propynyl group,
a 1-methyl-2-propynyl group, a methoxycarbonyl group, an
ethoxycarbonyl group, a 2,2,2-trifluoroethoxycarbonyl group, a
2,2,3,3-tetrafluoropropoxycarbonyl group, a vinyloxycarbonyl group,
a 1-propen-1-yloxycarbonyl group, a 2-propen-1-yloxycarbonyl group,
a 2-propynyloxycarbonyl group, a 1-methyl-2-propynyloxycarbonyl
group, a phenyloxycarbonyl group, a
2-trifluoromethylphenyloxycarbonyl group, a
4-fluoro-3-trifluoromethylphenyloxycarbonyl group, a
2,3,5,6-tetrafluorophenyloxycarbonyl group, or a
perfluorophenyloxycarbonyl group; and more preferably a hydrogen
atom, a fluorine atom, a methyl group, an ethyl group, a
trifluoromethyl group, a methoxycarbonyl group, an ethoxycarbonyl
group, a 2,2,2-trifluoroethoxycarbonyl group, a
2-propen-1-yloxycarbonyl group, or a 2-propynyloxycarbonyl
group.
[0085] When R.sup.21 and R.sup.22 are each an alkyl group, as
examples of a ring structure which R.sup.21 and R.sup.22 may be
bonded to each other, there are suitably exemplified an
ethane-1,2-diyl group, a propane-1,3-diyl group, a butane-1,4-diyl
group, and a pentane-1,5-diyl group, with a butane-1,4-diyl group
or a pentane-1,5-diyl group being preferred.
[0086] As specific examples of R.sup.23, there are suitably
exemplified a hydrogen atom; a halogen atom, such as a fluorine
atom, a chlorine atom, a bromine atom, etc.; a straight-chain alkyl
group, such as a methyl group, an ethyl group, an n-propyl group,
an n-butyl group, an n-pentyl group, an n-hexyl group, etc.; and a
branched alkyl group, such as an isopropyl group, a sec-butyl
group, a 2-pentyl group, a pentan-3-yl group, a tert-butyl group, a
tert-amyl group, etc. Above all, a hydrogen atom, a fluorine atom,
a chlorine atom, a methyl group, an ethyl group, an n-propyl group,
an n-butyl group, an isopropyl group, a sec-butyl group, or a
tert-butyl group is preferred, with a hydrogen atom, a fluorine
atom, a methyl group, or an ethyl group being more preferred.
[0087] As specific examples of R.sup.24, there are suitably
exemplified a straight-chain alkyl group, such as a methyl group,
an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl
group, an n-hexyl group, etc.; a branched alkyl group, such as an
isopropyl group, a sec-butyl group, a 2-pentyl group, a 3-pentyl
group, a tert-butyl group, a tert-amyl group, etc.; a halogenated
alkyl group, such as a fluoromethyl group, a difluoromethyl group,
a 2-chloroethyl group, a 2-fluoroethyl group, a 2,2-difluoroethyl
group, a 2,2,2-trifluoroethyl group, a 3-fluoropropyl group, a
3-chloropropyl group, a 3,3-difluoropropyl group, a
3,3,3-trifluoropropyl group, a 2,2,3,3-tetrafluoropropyl group, a
2,2,3,3,3-pentafluoropropyl group, etc.; a cycloalkyl group, such
as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a
cyclohexyl group, a cycloheptyl group, etc.; a halogenated
cycloalkyl group, such as a 4-fluorocyclohexyl group, a
4-chlorocyclohexyl group, etc.; an alkenyl group, such as a vinyl
group, a 1-propen-1-yl group, a 2-propen-1-yl group, a 2-buten-1-yl
group, a 3-buten-1-yl group, a 4-penten-1-yl group, a 5-hexen-1-yl
group, a 1-propen-2-yl group, a 1-buten-2-yl group, a
2-methyl-2-propen-1-yl group, etc.; a haloalkenyl group, such as a
3,3-difluoro-2-propen-1-yl group, a 4,4-difluoro-3-buten-1-yl
group, a 3,3-dichloro-2-propen-1-yl group, a
4,4-dichloro-3-buten-1-yl group, etc.; an alkynyl group, such as a
2-propynyl group, a 2-butynyl group, a 3-butynyl group, a
4-heptynyl group, a 1-methyl-2-propynyl group, a
1,1-dimethyl-2-propynyl group, a 1-methyl-3-butynyl group, a
1-methyl-4-heptynyl group, etc.; an alkoxyalkyl group, such as a
methoxymethyl group, an ethoxymethyl group, a methoxyethyl group,
an ethoxyethyl group, an n-propoxyethyl group, an n-butoxyethyl
group, a methoxypropyl group, an ethoxypropyl group, etc.; an
aralkyl group, such as a benzyl group, a 4-methylbenzyl group, a
4-tert-butylbenzyl group, a 4-fluorobenzyl group, a 4-chlorobenzyl
group, a 1-phenylethan-1-yl group, a 2-phenylethan-1-yl group, a
3-phenylpropan-1-yl group, etc.; an aryl group, such as a phenyl
group, a 2-methylphenyl group, a 3-methylphenyl group, a
4-methylphenyl group, a 4-tert-butylphenyl group, a 2-fluorophenyl
group, a 4-fluorophenyl group, a 2-trifluoromethylphenyl group, a
3-trifluoromethylphenyl group, a 4-trifluoromethylphenyl group, a
4-fluoro-2-trifluoromethylphenyl group, a
4-fluoro-3-trifluoromethylphenyl group, a 2,4-difluorophenyl group,
a 2,6-difluorophenyl group, a 3,5-difluorophenyl group, a
2,4,6-trifluorophenyl group, a 2,3,5,6-tetrafluorophenyl group, a
perfluorophenyl group, etc.; and the like.
[0088] Of the foregoing, R.sup.24 is preferably a methyl group, an
ethyl group, an n-propyl group, an n-butyl group, an isopropyl
group, a sec-butyl group, a 2,2,2-trifluoroethyl group, a
2,2,3,3-tetrafluoropropyl group, a cyclopropyl group, a cyclobutyl
group, a cyclopentyl group, a cyclohexyl group, a vinyl group, a
1-propen-1-yl group, a 2-propen-1-yl group, a 2-buten-1-yl group, a
3-buten-1-yl group, a 1-propen-2-yl group, a 1-buten-2-yl group, a
2-methyl-2-propen-1-yl group, a 3,3-difluoro-2-propen-1-yl group, a
4,4-difluoro-3-buten-1-yl group, a 3,3-dichloro-2-propen-1-yl
group, a 4,4-dichloro-3-buten-1-yl group, a 2-propynyl group, a
2-butynyl group, a 3-butynyl group, a 1-methyl-2-propynyl group, a
1,1-dimethyl-2-propynyl group, a 4-fluoro-3-trifluoromethylphenyl
group, or a perfluorophenyl group, and more preferably a methyl
group, an ethyl group, a 2,2,2-trifluoroethyl group, a
2,2,3,3-tetrafluoropropyl group, a 2-propen-1-yl group, a
2-propynyl group, a 2-butynyl group, or a 1-methyl-2-propynyl
group.
[0089] X.sup.1 represents an --S(.dbd.O) group, an
--S(.dbd.O).sub.2 group, or a --CR.sup.26R.sup.27 group. Specific
examples of R.sup.26 and R.sup.27 include a hydrogen atom; a
straight-chain alkyl group, such as a methyl group, an ethyl group,
an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl
group, etc.; a branched alkyl group, such as an isopropyl group, a
sec-butyl group, a 2-pentyl group, a 3-pentyl group, a tert-butyl
group, a tert-amyl group, etc.; or a halogenated alkyl group, such
as a trifluoromethyl group, a 2,2,2-trifluoroethyl group, a
2,2,3,3-tetrafluoropropyl group, a perfluorobutyl group, a
1,1,1,3,3,3-hexafluoroisopropyl group, etc., with a hydrogen atom
or a methyl group being preferred, and it is more preferred that
R.sup.26 and R.sup.27 each are a hydrogen atom.
[0090] Among the foregoing, X.sup.1 is more preferably an
--S(.dbd.O) group or an --S(.dbd.O).sub.2 group, and especially
preferably an --S(.dbd.O).sub.2 group.
[0091] As the compound represented by the foregoing general formula
(I-2), specifically, there are suitably exemplified the following
compounds.
(A) In the case where X.sup.1 is an --S(.dbd.O) group:
##STR00038## ##STR00039## ##STR00040## ##STR00041## ##STR00042##
##STR00043## ##STR00044##
(B) In the case where X.sup.1 is an --S(.dbd.O).sub.2 group:
##STR00045## ##STR00046## ##STR00047## ##STR00048## ##STR00049##
##STR00050## ##STR00051## ##STR00052## ##STR00053## ##STR00054##
##STR00055## ##STR00056## ##STR00057## ##STR00058## ##STR00059##
##STR00060##
(C) In the case where X.sup.1 is a --CR.sup.26R.sup.27 group:
##STR00061## ##STR00062## ##STR00063## ##STR00064## ##STR00065##
##STR00066## ##STR00067## ##STR00068## ##STR00069##
[0092] Among the aforementioned compounds, as the compound
represented by the general formula (I-2), the compounds having any
one of the structural formulae of A1 to A3, A7 to A17, A22 to A26,
A30 to A40, A43, B1 to B4, B6, B12 to B13, B16 to B17, B20 to B22,
B24, B26 to B33, B41 to B53, B63 to B78, C1 to C3, C7 to C17, C22
to C26, C30 to C46, and C49 to C50 are preferred; the compounds
having any one of the structural formulae of A1 to A2, A8, A9, A14
to A15, A31 to A36, A39, A40, B1 to B2, B13, B16, B26 to B28, B65
to B70, B74 to B75, C1 to C2, C8, C9, C14, C31 to C35, C39 to C40,
and C49 to C50 are more preferred; and at least one selected from
methyl 1,3,2-dioxathiolane-4-carboxylate 2-oxide (structural
formula A1), ethyl 1,3,2-dioxathiolane-4-carboxylate 2-oxide
(structural formula A2), 2-propenyl
1,3,2-dioxathiolane-4-carboxylate 2-oxide (structural formula A8),
2-propynyl 1,3,2-dioxathiolane-4-carboxylate 2-oxide (structural
formula A9), 2,2,2-trifluoroethyl 1,3,2-dioxathiolane-4-carboxylate
2-oxide (structural formula A14), methyl
5-fluoro1-1,3,2-dioxathiolane-4-carboxylate 2-oxide (structural
formula A31), dimethyl 1,3,2-dioxathiolane-4,5-dicarboxylate
2-oxide (structural formula A33), diethyl
1,3,2-dioxathiolane-4,5-dicarboxylate 2-oxide (structural formula
A34), methyl 1,3,2-dioxathiolane-4-carboxylate 2,2-dioxide
(structural formula B1), ethyl 1,3,2-dioxathiolane-4-carboxylate
2,2-dioxide (structural formula B2), 2-propenyl
1,3,2-dioxathiolane-4-carboxylate 2,2-dioxide (structural formula
B13), 2-propynyl 1,3,2-dioxathiolane-4-carboxylate 2,2-dioxide
(structural formula B16), 2,2,2-trifluoroethyl
1,3,2-dioxathiolane-4-carboxylate 2,2-dioxide (structural formula
B26), methyl 5-fluoro-1,3,2-dioxathiolane-4-carboxylate 2,2-dioxide
(structural formula B65), dimethyl
1,3,2-dioxathiolane-4,5-dicarboxylate 2,2-dioxide (structural
formula B68), diethyl 1,3,2-dioxathiolane-4,5-dicarboxylate
2,2-dioxide (structural formula B69), methyl
1,3-dioxolane-4-carboxylate (structural formula C1), ethyl
1,3-dioxolane-4-carboxylate (structural formula C2), 2-propenyl
1,3-dioxolane-4-carboxylate (structural formula C8), 2-propynyl
1,3-dioxolane-4-carboxylate (structural formula C9),
2,2,2-trifluoroethyl 1,3-dioxolane-4-carboxylate (structural
formula C14), methyl 5-fluoro-1,3-dioxolane-4-carboxylate
(structural formula C31), dimethyl 1,3-dioxolane-4,5-dicarboxylate
(structural formula C33), diethyl 1,3-dioxolane-4,5-dicarboxylate
(structural formula C34), and dimethyl
2,2-dimethyl-1,3-dioxolane-4,5-dicarboxylate (structural formula
C49) is especially preferred.
[0093] In the nonaqueous electrolytic solution of the present
invention, a content of the carboxylic acid ester compound
represented by the general formula (I-2) is preferably 0.001 to 10%
by mass in the nonaqueous electrolytic solution. So long as the
content is 10% by mass or less, there is less concern that a
surface film is excessively formed on an electrode, so that in the
case of using a battery at a high temperature and at a high
voltage, the storage characteristics are worsened. So long as the
content is 0.001% by mass or more, the formation of a surface film
is sufficient, and in the case of using a battery at a high
temperature and at a high voltage, an improving effect of the
storage characteristics is enhanced. The content is preferably
0.05% by mass or more, and more preferably 0.3% by mass or more in
the nonaqueous electrolytic solution. An upper limit thereof is
preferably 8% by mass or less, more preferably 5% by mass or less,
and especially preferably 3% by mass or less.
[Nonaqueous Electrolytic Solution of Embodiment 3]
[0094] According to the nonaqueous electrolytic solution of
Embodiment 3 of the present invention, in the nonaqueous
electrolytic solution having an electrolyte salt dissolved in a
nonaqueous solvent, the compound represented by the foregoing
general formula (I) wherein X is an
--S(.dbd.O).sub.2--R.sup.5--S(.dbd.O).sub.2-- group, and n is 1 or
2, more specifically the carboxylic acid ester compound represented
by the foregoing general formula (I-3) is contained in the
nonaqueous electrolytic solution.
[0095] Although the reasons why the nonaqueous electrolytic
solution of Embodiment 3 is able to greatly improve the
electrochemical characteristics of an energy storage device when
used at a high temperature and at a high voltage are not always
elucidated yet, the following may be considered.
[0096] In view of the fact that the compound represented by the
general formula (I-3), which is used in Embodiment 3, has a hetero
ring which is reductively decomposed at the .alpha.-position of the
carbonyl group to form a surface film, it has high reactivity and
quickly reacts with active sites of both a positive electrode and a
negative electrode, thereby forming a firmer surface film.
Therefore, it may be considered that not only the storage
characteristics at a high temperature and at a high voltage are
improved, but also the gas generation to be caused due to
decomposition of the solvent is inhibited.
[0097] The carboxylic acid ester compound which is contained in the
nonaqueous electrolytic solution of Embodiment 3 is represented by
the following general formula (I-3).
##STR00070##
[0098] In the formula, each of R.sup.31 and R.sup.32 independently
represents a hydrogen atom, a halogen atom, an alkyl group having 1
to 6 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, an aryl group having 6 to 12
carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, or a --C(.dbd.O)--OR.sup.34 group.
R.sup.33 represents a hydrogen atom, a halogen atom, or an alkyl
group having 1 to 6 carbon atoms, and m represents 1 or 2.
[0099] When m is 1, then L.sup.3 and R.sup.34 may be the same as or
different from each other and represent an alkyl group having 1 to
6 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, a cycloalkyl group having 3 to 6
carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, an alkenyl group having 2 to 6
carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, an alkynyl group having 3 to 6
carbon atoms, an alkoxyalkyl group having 2 to 6 carbon atoms, a
cyanoalkyl group having 2 to 6 carbon atoms, an aralkyl group
having 7 to 13 carbon atoms, in which at least one hydrogen atom
may be substituted with a halogen atom, or an aryl group having 6
to 12 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, and when m is 2, then L.sup.3
represents an alkylene group having 2 to 8 carbon atoms, an
alkenylene group having 4 to 8 carbon atoms, or an alkynylene group
having 4 to 8 carbon atoms, at least one hydrogen atom of L.sup.3
may be substituted with a halogen atom, and R.sup.34 is the same as
described above.
[0100] X.sup.2 represents an
--S(.dbd.O).sub.2--R.sup.35--S(.dbd.O).sub.2-- group, and R.sup.35
represents an alkylene group having 1 to 4 carbon atoms, in which
at least one hydrogen atom may be substituted with a halogen atom
or an alkyl group having 1 to 4 carbon atoms.
[0101] In the foregoing general formula (I-3), each of R.sup.31 and
R.sup.32 is independently preferably a hydrogen atom, a halogen
atom, an alkyl group having 1 to 6 carbon atoms, in which at least
one hydrogen atom may be substituted with a halogen atom, or a
--C(.dbd.O)--OR.sup.34 group, and more preferably a hydrogen atom,
a halogen atom, an alkyl group having 1 to 4 carbon atoms, in which
at least one hydrogen atom may be substituted with a halogen atom,
or a --C(.dbd.O)--OR.sup.34 group.
[0102] R.sup.33 is preferably a hydrogen atom or a halogen atom,
and more preferably a hydrogen atom. m represents 1 or 2, and
preferably 1. When m is 1, then L.sup.3 and R.sup.34 may be the
same as or different from each other and are preferably an alkyl
group having 1 to 6 carbon atoms, in which at least one hydrogen
atom may be substituted with a halogen atom, a cycloalkyl group
having 3 to 6 carbon atoms, in which at least one hydrogen atom may
be substituted with a halogen atom, an alkenyl group having 2 to 6
carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, an alkynyl group having 3 to 6
carbon atoms, or an aryl group having 6 to 12 carbon atoms, in
which at least one hydrogen atom may be substituted with a halogen
atom, and more preferably an alkenyl group having 2 to 6 carbon
atoms or an alkynyl group having 3 to 6 carbon atoms. When m is 2,
then L.sup.3 is preferably an alkylene group having 2 to 6 carbon
atoms, an alkenylene group having 4 to 8 carbon atoms, or an
alkynylene group having 4 to 8 carbon atoms, and more preferably an
alkylene group having 2 to 4 carbon atoms, an alkenylene group
having 4 to 6 carbon atoms, or an alkynylene group having 4 to 6
carbon atoms.
[0103] R.sup.35 is preferably an alkylene group having 1 to 2
carbon atoms, in which at least one hydrogen atom may be
substituted with a fluorine atom or a methyl group, and more
preferably a methylene group.
[0104] As specific examples of R.sup.31 and R.sup.32, there are
suitably exemplified a hydrogen atom; a halogen atom, such as a
fluorine atom, a chlorine atom, a bromine atom, etc.; a
straight-chain alkyl group, such as a methyl group, an ethyl group,
an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl
group, etc.; a branched alkyl group, such as an isopropyl group, a
sec-butyl group, a 2-pentyl group, a 3-pentyl group, a tert-butyl
group, a tert-amyl group, etc.; a halogenated alkyl group, such as
a fluoromethyl group, a difluoromethyl group, a trifluoromethyl
group, a 2-chloroethyl group, a 2-fluoroethyl group, a
2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, a
3-fluoropropyl group, a 3-chloropropyl group, a 3,3-difluoropropyl
group, a 3,3,3-trifluoropropyl group, a 2,2,3,3-tetrafluoropropyl
group, a 2,2,3,3,3-pentafluoropropyl group, etc.; and an aryl
group, such as a phenyl group, a 2-methylphenyl group, a
3-methylphenyl group, a 4-methylphenyl group, a 4-tert-butylphenyl
group, a 2-fluorophenyl group, a 4-fluorophenyl group, a
2-trifluoromethylphenyl group, a 3-trifluoromethylphenyl group, a
4-trifluoromethylphenyl group, a 4-fluoro-2-trifluoromethylphenyl
group, a 4-fluoro-3-trifluoromethylphenyl group, a
2,6-difluorophenyl group, a 3,5-difluorophenyl group, a
2,4,6-trifluorophenyl group, a 2,3,5,6-tetrafluorophenyl group, a
perfluorophenyl group, etc.; and also a methoxycarbonyl group, an
ethoxycarbonyl group, a 2,2,2-trifluoroethoxycarbonyl group, a
2,2,3,3-tetrafluoropropoxycarbonyl group, a cyclopentyloxycarbonyl
group, a cyclohexyloxycarbonyl group, a vinyloxycarbonyl group, a
1-propen-1-yloxycarbonyl group, a 2-propen-1-yloxycarbonyl group, a
2-propynyloxycarbonyl group, a 1-methyl-2-propynyloxycarbonyl
group, a benzyloxycarbonyl group, a phenyloxycarbonyl group, a
4-fluorophenyloxycarbonyl group, a
2-trifluoromethylphenyloxycarbonyl group, a
4-fluoro-3-trifluoromethylphenyloxycarbonyl group, a
2,3,5,6-tetrafluorophenyloxycarbonyl group, a
perfluorophenyloxycarbonyl group, and the like.
[0105] Of the foregoing, R.sup.31 and R.sup.32 are preferably a
hydrogen atom, a fluorine atom, a chlorine atom, a methyl group, an
ethyl group, an n-propyl group, an n-butyl group, an n-pentyl
group, an n-hexyl group, an isopropyl group, a sec-butyl group, a
tert-butyl group, a trifluoromethyl group, a 2,2,2-trifluoroethyl
group, a 2,2,3,3-tetrafluoropropyl group, a methoxycarbonyl group,
an ethoxycarbonyl group, a 2,2,2-trifluoroethoxycarbonyl group, a
2,2,3,3-tetrafluoropropoxycarbonyl group, a vinyloxycarbonyl group,
a 1-propen-1-yloxycarbonyl group, a 2-propen-1-yloxycarbonyl group,
a 2-propynyloxycarbonyl group, a 1-methyl-2-propynyloxycarbonyl
group, a phenyloxycarbonyl group, a
2-trifluoromethylphenyloxycarbonyl group, a
4-fluoro-3-trifluoromethylphenyloxycarbonyl group, a
2,3,5,6-tetrafluorophenyloxycarbonyl group, or a
perfluorophenyloxycarbonyl group; and more preferably a hydrogen
atom, a fluorine atom, a methyl group, an ethyl group, a
trifluoromethyl group, a 2-propen-1-yloxycarbonyl group, or a
2-propynyloxycarbonyl group.
[0106] As specific examples of R.sup.33, there are suitably
exemplified a hydrogen atom; a halogen atom, such as a fluorine
atom, a chlorine atom, a bromine atom, etc.; a straight-chain alkyl
group, such as a methyl group, an ethyl group, an n-propyl group,
an n-butyl group, an n-pentyl group, an n-hexyl group, etc.; and a
branched alkyl group, such as an isopropyl group, a sec-butyl
group, a 2-pentyl group, a pentan-3-yl group, a tert-butyl group, a
tert-amyl group, etc. Above all, a hydrogen atom, a fluorine atom,
a chlorine atom, a methyl group, an ethyl group, an n-propyl group,
an n-butyl group, an isopropyl group, a sec-butyl group, or a
tert-butyl group is preferred, with a hydrogen atom, a fluorine
atom, a methyl group, or an ethyl group being more preferred.
[0107] As specific examples of L.sup.3, there are suitably
exemplified the following groups.
(i) In the case of m=1:
[0108] There are suitably exemplified a straight-chain alkyl group,
such as a methyl group, an ethyl group, an n-propyl group, an
n-butyl group, an n-pentyl group, an n-hexyl group, etc.; a
branched alkyl group, such as an isopropyl group, a sec-butyl
group, a 2-pentyl group, a 3-pentyl group, a tert-butyl group, a
tert-amyl group, etc.; a halogenated alkyl group, such as a
fluoromethyl group, a difluoromethyl group, a 2-chloroethyl group,
a 2-fluoroethyl group, a 2,2-difluoroethyl group, a
2,2,2-trifluoroethyl group, a 3-fluoropropyl group, a
3-chloropropyl group, a 3,3-difluoropropyl group, a
3,3,3-trifluoropropyl group, a 2,2,3,3-tetrafluoropropyl group, a
2,2,3,3,3-pentafluoropropyl group, etc.; a cycloalkyl group, such
as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a
cyclohexyl group, a cycloheptyl group, etc.; a halogenated
cycloalkyl group, such as a 4-fluorocyclohexyl group, a
4-chlorocyclohexyl group, etc.; an alkenyl group, such as a vinyl
group, a 1-propen-1-yl group, a 2-propen-1-yl group, a 2-buten-1-yl
group, a 3-buten-1-yl group, a 4-penten-1-yl group, a 5-hexen-1-yl
group, a 1-propen-2-yl group, a 1-buten-2-yl group, a
2-methyl-2-propen-1-yl group, etc.; a haloalkenyl group, such as a
3,3-difluoro-2-propen-1-yl group, a 4,4-difluoro-3-buten-1-yl
group, a 3,3-dichloro-2-propen-1-yl group, a
4,4-dichloro-3-buten-1-yl group, etc.; an alkynyl group, such as a
2-propynyl group, a 2-butynyl group, a 3-butynyl group, a
4-heptynyl group, a 1-methyl-2-propynyl group, a
1,1-dimethyl-2-propynyl group, a 1-methyl-3-butynyl group, a
1-methyl-4-heptynyl group, etc.; an alkoxyalkyl group, such as a
methoxymethyl group, an ethoxymethyl group, a methoxyethyl group,
an ethoxyethyl group, an n-propoxyethyl group, an n-butoxyethyl
group, a methoxypropyl group, an ethoxypropyl group, etc.; a
cyanoalkyl group, such as a cyanomethyl group, a 2-cyanoethyl
group, a 3-cyanopropyl group, a 4-cyanobutyl group. etc.; an
aralkyl group, such as a benzyl group, a 4-methylbenzyl group, a
4-tert-butylbenzyl group, a 4-fluorobenzyl group, a 4-chlorobenzyl
group, a 1-phenylethan-1-yl group, a 2-phenylethan-1-yl group, a
3-phenylpropan-1-yl group, etc.; an aryl group, such as a phenyl
group, a 2-methylphenyl group, a 3-methylphenyl group, a
4-methylphenyl group, a 4-tert-butylphenyl group, a 2-fluorophenyl
group, a 4-fluorophenyl group, a 2-trifluoromethylphenyl group, a
3-trifluoromethylphenyl group, a 4-trifluoromethylphenyl group, a
4-fluoro-2-trifluoromethylphenyl group, a
4-fluoro-3-trifluoromethylphenyl group, a 2,6-difluorophenyl group,
a 3,5-difluorophenyl group, a 2,4,6-trifluorophenyl group, a
2,3,5,6-tetrafluorophenyl group, a perfluorophenyl group, etc.; and
the like.
[0109] In the case of m=1, of the foregoing, L.sup.3 is preferably
a methyl group, an ethyl group, an n-propyl group, an n-butyl
group, an isopropyl group, a sec-butyl group, a
2,2,2-trifluoroethyl group, a 2,2,3,3-tetrafluoropropyl group, a
cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a
cyclohexyl group, a vinyl group, a 1-propen-1-yl group, a
2-propen-1-yl group, a 2-buten-1-yl group, a 3-buten-1-yl group, a
1-propen-2-yl group, a 1-buten-2-yl group, a 2-methyl-2-propen-1-yl
group, a 3,3-difluoro-2-propen-1-yl group, a
4,4-difluoro-3-buten-1-yl group, a 3,3-dichloro-2-propen-1-yl
group, a 4,4-dichloro-3-buten-1-yl group, a 2-propynyl group, a
2-butynyl group, a 3-butynyl group, a 1-methyl-2-propynyl group, a
1,1-dimethyl-2-propynyl group, a 2,3,5,6-tetrafluorophenyl group,
or a perfluorophenyl group; and more preferably a methyl group, an
ethyl group, a 2,2,2-trifluoroethyl group, a
2,2,3,3-tetrafluoropropyl group, a 2-propen-1-yl group, a
2-propynyl group, a 2-butynyl group, or a 1-methyl-2-propynyl
group.
(ii) In the case of m=2:
[0110] There are suitably exemplified a straight-chain alkylene
group, such as an ethylene group, a propane-1,3-diyl group, a
butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl
group, etc.; a branched alkylene group, such as a propane-1,2-diyl
group, a butane-1,3-diyl group, a butane-2,3-diyl group, a
2-methylpropane-1,2-diyl group, a 2,2-dimethylpropane-1,3-diyl
group, etc.; a haloalkylene group, such as a
2,2-difluoropropane-1,3-diyl group, a
2,2,3,3-tetrafluorobutane-1,4-diyl group, a
2,2,3,3,4,4-hexafluoropentane-1,5-diyl group, a
2,2,3,3,4,4,5,5-octafluorohexane-1,6-diyl group, a
2,2-dichloropropane-1,3-diyl group, a
2,2,3,3-tetrachlorobutene-1,4-diyl group, etc.; an alkenylene
group, such as a 2-butene-1,4-diyl group, a 2-pentene-1,5-diyl
group, a 3-hexene-1,6-diyl group, a 3-hexene-2,5-diyl group, a
2,5-dimethyl-3-hexene-2,5-diyl group, etc.; and an alkynylene
group, such as a 2-butyne-1,4-diyl group, a 2-pentyne-1,5-diyl
group, a 3-hexyne-1,6-diyl group, a 3-hexyne-2,5-diyl group, a
2,5-dimethyl-3-hexyne-2,5-diyl group, etc.
[0111] In the case of m=2, of the foregoing, L.sup.3 is preferably
an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl
group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a
propane-1,2-diyl group, a butane-2,3-diyl group, a
2,2-dimethylpropane-1,3-diyl group, a 2-butene-1,4-diyl group, a
3-hexene-2,5-diyl group, a 2-butyne-1,4-diyl group, or a
3-hexyne-2,5-diyl group; and more preferably a 2-buten-1,4-diyl
group or a 2-butyne-1,4-diyl group.
[0112] As specific examples of X.sup.2, there are suitably
exemplified a bis(sulfonyl)methyl group, a 1,1-bis(sulfonyl)ethyl
group, a 1,1-bis(sulfonyl)propyl group, a 1,1-bis(sulfonyl)butyl
group, a 2,2-bis(sulfonyl)propyl group, a 2,2-bis(sulfonyl)butyl
group, a 3,3-bis(sulfonyl)pentyl group, a bis(sulfonyl)fluoromethyl
group, a bis(sulfonyl)difluoromethyl group, a
1,2-bis(sulfonyl)ethyl group, a 1,2-bis(sulfonyl)propyl group, a
2,3-bis(sulfonyl)butyl group, a 1,3-bis(sulfonyl)propyl group, and
a 1,4-bis(sulfonyl)butyl group. Among those, a bis(sulfonyl)methyl
group, a 1,1-bis(sulfonyl)ethyl group, a bis(sulfonyl)fluoromethyl
group, or a 1,2-bis(sulfonyl)ethyl group is preferred, with a
bis(sulfonyl)methyl group being more preferred.
[0113] As the carboxylic acid ester compound represented by the
foregoing general formula (I-3), specifically, there are suitably
exemplified the following compounds.
##STR00071## ##STR00072## ##STR00073## ##STR00074## ##STR00075##
##STR00076## ##STR00077## ##STR00078## ##STR00079## ##STR00080##
##STR00081## ##STR00082## ##STR00083## ##STR00084## ##STR00085##
##STR00086##
[0114] Among the aforementioned compounds, as the compound
represented by the general formula (I-3), the compounds having any
one of the structural formulae of D1 to D4, D6, D11 to D13, D17,
D18, D20 to D22, D24 to D26, D30, D31, D37 to D40, D49 to D64, and
D73 to D75 are more preferred; the compounds having any one of the
structural formulae of D1, D2, D13, D17, D24, D25, D49 to D55, D58,
and D59 are still more preferred; and methyl
1,5,2,4-dioxadithiepane-6-carboxylate 2,2,4,4-tetraoxide
(structural formula D1), ethyl
1,5,2,4-dioxadithiepane-6-carboxylate 2,2,4,4-tetraoxide
(structural formula D2), 2-propenyl
1,5,2,4-dioxadithiepane-6-carboxylate 2,2,4,4-tetraoxide
(structural formula D13), 2-propynyl
1,5,2,4-dioxadithiepane-6-carboxylate 2,2,4,4-tetraoxide
(structural formula D17), 2,2,2-trifluoroethyl
1,5,2,4-dioxadithiepane-6-carboxylate 2,2,4,4-tetraoxide
(structural formula D24), methyl
1,5,2,4-dioxadithiepane-7-fluoro-6-carboxylate 2,2,4,4-tetraoxide
(structural formula D49), dimethyl
1,5,2,4-dioxadithiepane-6,7-dicarboxylate 2,2,4,4-tetraoxide
(structural formula D53), and diethyl
1,5,2,4-dioxadithiepane-6,7-dicarboxylate 2,2,4,4-tetraoxide
(structural formula D54) are especially preferred.
[0115] In the nonaqueous electrolytic solution of the present
invention, a content of the carboxylic acid ester compound
represented by the foregoing general formula (I-3) is preferably
0.001 to 10% by mass in the nonaqueous electrolytic solution. So
long as the content is 10% by mass or less, there is less concern
that a surface film is excessively formed on an electrode, so that
in the case of using a battery at a high temperature and at a high
voltage, the storage characteristics are worsened. So long as the
content is 0.001% by mass or more, the formation of a surface film
is sufficient, and in the case of using a battery at a high
temperature and at a high voltage, an improving effect of the
storage characteristics is enhanced. The content is preferably
0.01% by mass or more, and more preferably 0.3% by mass or more in
the nonaqueous electrolytic solution. An upper limit thereof is
preferably 8% by mass or less, more preferably 7% by mass or less,
and especially preferably 5% by mass or less.
[Nonaqueous Solvent]
[0116] As the nonaqueous solvent which is used for the nonaqueous
electrolytic solution of the present invention, there are suitably
exemplified one or more selected from cyclic carbonates, linear
esters, lactones, ethers, and amides. In order that the
electrochemical characteristics may be synergistically improved at
a high temperature, it is preferred to include a linear ester, it
is more preferred to include a linear carbonate, and it is most
preferred to include both a cyclic carbonate and a linear
carbonate.
[0117] The term "linear ester" is used as a concept including a
linear carbonate and a linear carboxylic acid ester.
[0118] As the cyclic carbonate, there is exemplified one or more
selected from ethylene carbonate (EC), propylene carbonate (PC),
1,2-butylene carbonate, 2,3-butylene carbonate,
4-fluoro-1,3-dioxolan-2-one (FEC), trans- or
cis-4,5-difluoro-1,3-dioxolan-2-one (the both will be hereunder
named generically as "DFEC"), vinylene carbonate (VC), vinyl
ethylene carbonate (VEC), and 4-ethynyl-1,3-dioxolan-2-one (EEC).
One or more selected from ethylene carbonate, propylene carbonate,
4-fluoro-1,3-dioxolan-2-one, vinylene carbonate, and
4-ethynyl-1,3-dioxolan-2-one (EEC) are more suitable.
[0119] Use of at least one of cyclic carbonates having an
unsaturated bond, such as a carbon-carbon double bond, a
carbon-carbon triple bond, etc., or a fluorine atom is preferred
because the electrochemical characteristics are much more improved
at a high temperature, and it is more preferred to contain both a
cyclic carbonate having an unsaturated bond, such as a
carbon-carbon double bond, a carbon-carbon triple bond, etc., and a
cyclic carbonate having a fluorine atom. As the cyclic carbonate
having an unsaturated bond, such as a carbon-carbon double bond, a
carbon-carbon triple bond, etc., VC, VEC, or EEC is more preferred,
and as the cyclic carbonate having a fluorine atom, FEC or DFEC is
more preferred.
[0120] A content of the cyclic carbonate having an unsaturated
bond, such as a carbon-carbon double bond, a carbon-carbon triple
bond, etc., is preferably 0.07% by volume or more, more preferably
0.2% by volume or more, and still more preferably 0.7% by volume or
more relative to a total volume of the nonaqueous solvent, and when
an upper limit thereof is preferably 7% by volume or less, more
preferably 4% by volume or less, and still more preferably 2.5% by
volume or less, stability of a surface film can be much more
increased at a high temperature without impairing Li ion
permeability, and hence, such is preferred.
[0121] A content of the cyclic carbonate having a fluorine atom is
preferably 0.07% by volume or more, more preferably 4% by volume or
more, and still more preferably 7% by volume or more relative to a
total volume of the nonaqueous solvent, and when an upper limit
thereof is preferably 35% by volume or less, more preferably 25% by
volume or less, and still more preferably 15% by volume or less,
stability of a surface film can be much more increased at a high
temperature without impairing Li ion permeability, and hence, such
is preferred.
[0122] In the case where the nonaqueous solvent includes both the
cyclic carbonate having an unsaturated bond, such as a
carbon-carbon double bond, a carbon-carbon triple bond, etc., and
the cyclic carbonate having a fluorine atom, the content of the
cyclic carbonate having an unsaturated bond, such as a
carbon-carbon double bond, a carbon-carbon triple bond, etc., is
preferably 0.2% by volume or more, more preferably 3% by volume or
more, and still more preferably 7% by volume or more relative to
the content of the cyclic carbonate having a fluorine atom, and
when an upper limit thereof is preferably 40% by volume or less,
more preferably 30% by volume or less, and still more preferably
15% by volume or less, stability of a surface film can be much more
increased at a high temperature without impairing Li ion
permeability, and hence, such is especially preferred.
[0123] When the nonaqueous solvent includes both ethylene carbonate
and the cyclic carbonate having an unsaturated bond, such as a
carbon-carbon double bond, a carbon-carbon triple bond, etc.,
stability of a surface film to be formed on an electrode at a high
temperature is increased, and hence, such is preferred. A content
of ethylene carbonate and the cyclic carbonate having an
unsaturated bond, such as a carbon-carbon double bond, a
carbon-carbon triple bond, etc., is preferably 3% by volume or
more, more preferably 5% by volume or more, and still more
preferably 7% by volume relative to a total volume of the
nonaqueous solvent. An upper limit thereof is preferably 45% by
volume or less, more preferably 35% by volume or less, and still
more preferably 25% by volume or less.
[0124] These solvents may be used solely; in the case where a
combination of two or more of the solvents is used, the
electrochemical characteristics at a high temperature are more
improved, and hence, such is preferred; and use of a combination of
three or more thereof is especially preferred. As suitable
combinations of these cyclic carbonates, EC and PC; EC and VC; PC
and VC; VC and FEC; EC and FEC; PC and FEC; FEC and DFEC; EC and
DFEC; PC and DFEC; VC and DFEC; VEC and DFEC; VC and EEC; EC and
EEC; EC, PC and VC; EC, PC and FEC; EC, VC and FEC; EC, VC and VEC;
EC, VC and EEC; EC, EEC and FEC; PC, VC and FEC; EC, VC and DFEC;
PC, VC and DFEC; EC, PC, VC and FEC; EC, PC, VC and DFEC; and the
like are preferred. Among the aforementioned combinations,
combinations, such as EC and VC; EC and FEC; PC and FEC; EC, PC and
VC; EC, PC and FEC; EC, VC and FEC; EC, VC and EEC; EC, EEC and
FEC; PC, VC and FEC; EC, PC, VC and FEC; etc., are more
preferred.
[0125] In the case of Embodiment 2, namely in the case of using the
carboxylic acid ester compound represented by the foregoing general
formula (I-2), combinations including PC, such as PC and FEC; EC,
PC and VC; EC, PC and FEC; PC, VC and FEC; EC, PC, VC and FEC;
etc., are still more preferred because battery characteristics at a
high voltage are improved.
[0126] As the linear ester, there are suitably exemplified one or
more asymmetric linear carbonates selected from methyl ethyl
carbonate (MEC), methyl propyl carbonate (MPC), methyl isopropyl
carbonate (MIPC), methyl butyl carbonate, and ethyl propyl
carbonate; one or more symmetric linear carbonates selected from
dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl
carbonate, and dibutyl carbonate; one or more linear carboxylic
acid esters selected from methyl pivalate (MPiv), ethyl pivalate
(EPiv), propyl pivalate (PPiv), methyl propionate (MP), ethyl
propionate (EP), propyl propionate (PP), methyl acetate (MA), and
ethyl acetate (EA); one or more asymmetric fluorinated linear
carbonates selected from methyl (2,2,2-trifluoroethyl) carbonate
(MTFEC), ethyl (2,2,2-trifluoroethyl) carbonate, fluoromethyl
(methyl) carbonate (FMMC), methyl (2,2,3,3-tetrafluoropropyl)
carbonate (MTEFPC), ethyl (2,2,3,3-tetrafluoropropyl) carbonate,
2-fluoroethyl (methyl) carbonate (2-FEMC), and difluoromethyl
(fluoromethyl) carbonate; and one or more symmetric fluorinated
linear carbonates selected from bis(2-fluoroethyl) carbonate,
bis(2,2,3,3-tetrafluoropropyl) carbonate, bis(2,2,2-trifluoroethyl)
carbonate, and bis(fluoromethyl) carbonate.
[0127] Among the aforementioned linear esters, linear esters having
a methyl group selected from linear carbonates, such as dimethyl
carbonate (DMC), methyl ethyl carbonate (MEC), methyl propyl
carbonate (MPC), methyl isopropyl carbonate (MIPC), methyl butyl
carbonate, etc.; and linear carboxylic acid esters, such as methyl
propionate (MP), ethyl propionate (EP), propyl propionate (PP),
methyl acetate (MA), ethyl acetate (EA), etc., are preferred, and
linear carbonates having a methyl group are especially
preferred.
[0128] In the case of using a linear carbonate, it is preferred to
use two or more thereof. Furthermore, it is more preferred that
both the symmetric linear carbonate and the asymmetric linear
carbonate are included, and it is still more preferred that a
content of the symmetric linear carbonate is more than a content of
the asymmetric linear carbonate.
[0129] Although the content of the linear ester is not particularly
limited, it is preferred to use the linear ester in an amount in
the range of from 60 to 90% by volume relative to a total volume of
the nonaqueous solvent. When the content is 60% by volume or more,
the viscosity of the nonaqueous electrolytic solution does not
become excessively high, and when it is 90% by volume or less,
there is less concern that an electroconductivity of the nonaqueous
electrolytic solution is decreased, whereby the electrochemical
characteristics at a high temperature are worsened, and therefore,
it is preferred that the content of the linear ester falls within
the aforementioned range.
[0130] From the viewpoint of improving the electrochemical
characteristics at a high voltage, it is preferred that at least
one selected from symmetric fluorinated linear carbonates and
asymmetric fluorinated linear carbonates is included, and an
asymmetric fluorinated linear carbonate having a methyl group,
which is selected from methyl (2,2,2-trifluoroethyl) carbonate
(MTFEC), 2-fluoroethyl (methyl) carbonate (2-FEMC), methyl
(2,2,3,3-tetrafluoropropyl) carbonate (MTEFPC), and difluoromethyl
(fluoromethyl) carbonate, is more preferred.
[0131] A proportion of the volume occupied by the symmetric linear
carbonate in the linear carbonate is preferably 51% by volume or
more, and more preferably 55% by volume or more. An upper limit
thereof is preferably 95% by volume or less, and more preferably
85% by volume or less. It is especially preferred that dimethyl
carbonate is included in the symmetric linear carbonate. It is more
preferred that the asymmetric linear carbonate has a methyl group,
and methyl ethyl carbonate is especially preferred. The
aforementioned case is preferred because the electrochemical
characteristics at a high temperature are much more improved.
[0132] As for a proportion of the cyclic carbonate and the linear
ester, from the viewpoint of improving the electrochemical
characteristics at a high temperature, a ratio of the cyclic
carbonate to the linear ester (volume ratio) is preferably from
10/90 to 45/55, more preferably from 15/85 to 40/60, and especially
preferably from 20/80 to 35/65.
[0133] As other nonaqueous solvents, there are suitably exemplified
one or more selected from cyclic ethers, such as tetrahydrofuran,
2-methyltetrahydrofuran, 1,4-dioxane, etc.; linear ethers, such as
1,2-dimethoxyethane, 1,2-diethoxyethane, 1,2-butoxyethane, etc.;
amides, such as dimethylformamide, etc.; sulfones, such as
sulfolane, etc.; and lactones, such as .gamma.-butyrolactone (GBL),
.gamma.-valerolactone, .alpha.-angelicalactone, etc.
[0134] The aforementioned nonaqueous solvents are generally mixed
and used for the purpose of achieving appropriate physical
properties. As for a combination thereof, for example, there are
suitably exemplified a combination of a cyclic carbonate and a
linear carbonate, a combination of a cyclic carbonate and a linear
carboxylic acid ester, a combination of a cyclic carbonate, a
linear carbonate, and a lactone, a combination of a cyclic
carbonate, a linear carbonate, and an ether, a combination of a
cyclic carbonate, a linear carbonate, and a linear carboxylic acid
ester, and the like.
[0135] For the purpose of much more improving stability of a
surface film at a high temperature, it is preferred to further add
other additives in the nonaqueous electrolytic solution.
[0136] As specific examples of other additives, there are
exemplified compounds of the following (A) to (I).
[0137] (A) One or more nitriles selected from acetonitrile,
propionitrile, succinonitrile, glutaronitrile, adiponitrile,
pimelonitrile, suberonitrile, and sebaconitrile.
[0138] (B) Aromatic compounds having a branched alkyl group, such
as cyclohexylbenzene, fluorocyclohexylbenzene compounds (e.g.,
1-fluoro-2-cyclohexylbenzene, 1-fluoro-3-cyclohexylbenzene, and
1-fluoro-4-cyclohexylbenzene), tert-butylbenzene, tert-amylbenzene,
1-fluoro-4-tert-butylbenzene, etc., and aromatic compounds, such as
biphenyl, terphenyl (including o-, m-, and p-forms), diphenyl
ether, fluorobenzene, difluorobenzene (including o-, m-, and
p-forms), anisole, 2,4-difluoroanisole, a partial hydride of
terphenyl (e.g., 1,2-dicyclohexylbenzene, 2-phenylbicyclohexyl,
1,2-diphenylcyclohexane, and o-cyclohexylbiphenyl), etc.
[0139] (C) One or more isocyanate compounds selected from methyl
isocyanate, ethyl isocyanate, butyl isocyanate, phenyl isocyanate,
tetramethylene diisocyanate, hexamethylene diisocyanate,
octamethylene diisocyanate, 1,4-phenylene diisocyanate,
2-isocyanatoethyl acrylate, and 2-isocyanatoethyl methacrylate.
[0140] (D) One or more triple bond-containing compounds selected
from 2-propynyl methyl carbonate, 2-propynyl acetate, 2-propynyl
formate, 2-propynyl methacrylate, 2-propynyl methanesulfonate,
2-propynyl vinylsulfonate, 2-propynyl
2-(methanesulfonyloxy)propionate, di(2-propynyl) oxalate, methyl
2-propynyl oxalate, ethyl 2-propynyl oxalate, di(2-propynyl)
glutarate, 2-butyne-1,4-diyl dimethanesulfonate, 2-butyne-1,4-diyl
diformate, and 2,4-hexadiyne-1,6-diyl dimethanesulfonate.
[0141] (E) One or more cyclic or linear S.dbd.O group-containing
compounds selected from sultones, such as 1,3-propanesultone,
1,3-butanesultone, 2,4-butanesultone, 1,4-butanesultone,
1,3-propenesultone, 2,2-dioxide-1,2-oxathiolane-4-yl acetate,
5,5-dimethyl-1,2-oxathiolane-4-one 2,2-dioxide, etc.; cyclic
sulfites, such as ethylene sulfite,
hexahydrobenzo[1,3,2]dioxathiolane-2-oxide (also called
1,2-cyclohexanediol cyclic sulfite),
5-vinyl-hexahydro-1,3,2-benzodioxathiol-2-oxide,
4-(methylsulfonylmethyl)-1,3,2-dioxathiolane-2-oxide, etc.;
sulfonic acid esters, such as butane-2,3-diyl dimethanesulfonate,
butane-1,4-diyl dimethanesulfonate, methylene methanedisulfonate,
dimethyl methanedisulfonate, pentafluorophenyl methanesulfonate,
etc.; and vinylsulfone compounds, such as divinylsulfone,
1,2-bis(vinylsulfonyl)ethane, bis(2-vinylsulfonylethyl) ether,
etc.
[0142] (F) Cyclic acetal compounds, such as 1,3-dioxolane,
1,3-dioxane, 1,3,5-trioxane, etc.
[0143] (G) One or more phosphorus-containing compounds selected
from trimethyl phosphate, tributyl phosphate, trioctyl phosphate,
tris(2,2,2-trifluoroethyl) phosphate, bis(2,2,2-trifluoroethyl)
methyl phosphate, bis(2,2,2-trifluoroethyl) ethyl phosphate,
bis(2,2,2-trifluoroethyl) 2,2-difluoroethyl phosphate,
bis(2,2,2-trifluoroethyl) 2,2,3,3-tetrafluoropropyl phosphate,
bis(2,2-difluoroethyl) 2,2,2-trifluoroethyl phosphate,
bis(2,2,3,3-tetrafluoropropyl) 2,2,2-trifluoroethyl phosphate,
(2,2,2-trifluoroethyl) (2,2,3,3-tetrafluoropropyl)methyl phosphate,
tris(1,1,1,3,3,3-hexafluoropropan-2-yl) phosphate, methyl
methylenebisphosphonate, ethyl methylenebisphosphonate, methyl
ethylenebisphosphonate, ethyl ethylenebisphosphonate, methyl
butylenebisphosphonate, ethyl butylenebisphosphonate, methyl
2-(dimethylphosphoryl)acetate, ethyl 2-(dimethylphosphoryl)acetate,
methyl 2-(diethylphosphoryl) acetate, ethyl 2-(diethylphosphoryl)
acetate, 2-propynyl 2-(dimethylphosphoryl)acetate, 2-propynyl
2-(diethylphosphoryl)acetate, methyl
2-(dimethoxyphosphoryl)acetate, ethyl
2-(dimethoxyphosphoryl)acetate, methyl
2-(diethoxyphosphoryl)acetate, ethyl 2-(diethoxyphosphoryl)
acetate, 2-propynyl 2-(dimethoxyphosphoryl) acetate, 2-propynyl
2-(diethoxyphosphoryl)acetate, methyl pyrophosphate, and ethyl
pyrophosphate.
[0144] (H) Linear carboxylic acid anhydrides, such as acetic
anhydride, propionic anhydride, etc., and cyclic acid anhydrides,
such as succinic anhydride, maleic anhydride, 3-allylsuccinic
anhydride, glutaric anhydride, itaconic anhydride,
3-sulfo-propionic anhydride, etc.
[0145] (I) Cyclic phosphazene compounds, such as
methoxypentafluorocyclotriphosphazene,
ethoxypentafluorocyclotriphosphazene,
phenoxypentafluorocyclotriphosphazene,
ethoxyheptafluorocyclotetraphosphazene, etc.
[0146] Of the foregoing, when at least one selected from (A) the
nitriles, (B) the aromatic compounds, and (C) the isocyanate
compounds is included, the electrochemical characteristics at a
high temperature and at a high voltage are much more improved, and
hence, such is preferred.
[0147] Of (A) the nitriles, one or more selected from
succinonitrile, glutaronitrile, adiponitrile, and pimelonitrile are
more preferred.
[0148] Of (B) the aromatic compounds, one or more selected from
biphenyl, terphenyl (including o-, m-, and p-forms), fluorobenzene,
cyclohexylbenzene, tert-butylbenzene, and tert-amylbenzene are more
preferred; and one or more selected from biphenyl, o-terphenyl,
fluorobenzene, cyclohexylbenzene, and tert-amylbenzene are
especially preferred.
[0149] Of (C) the isocyanate compounds, one or more selected from
hexamethylene diisocyanate, octamethylene diisocyanate,
2-isocyanatoethyl acrylate, and 2-isocyanatoethyl methacrylate are
more preferred.
[0150] A content of each of the aforementioned additives (A) to (C)
is preferably 0.01 to 7% by mass in the nonaqueous electrolytic
solution. When the content falls within this range, a surface film
is sufficiently formed without causing an excessive increase of the
thickness, and stability of the surface film at a high temperature
is much more improved. The content is more preferably 0.05% by mass
or more, and still more preferably 0.1% by mass or more in the
nonaqueous electrolytic solution, and an upper limited thereof is
more preferably 5% by mass or less, and still more preferably 3% by
mass or less.
[0151] When (D) the triple bond-containing compound, (E) the cyclic
or linear S.dbd.O group-containing compound selected from sultones,
cyclic sulfites, sulfonic acid esters, and vinylsulfones, (F) the
cyclic acetal compound, (G) the phosphorus-containing compound, (H)
the cyclic acid anhydride, or (I) the cyclic phosphazene compound
is included, stability of a surface film at a high temperature is
much more improved, and hence, such is preferred.
[0152] As (D) the triple bond-containing compound, one or more
selected from 2-propynyl methyl carbonate, 2-propynyl methacrylate,
2-propynyl methanesulfonate, 2-propynyl vinylsulfonate, 2-propynyl
2-(methanesulfonyloxy)propionate, di(2-propynyl) oxalate, methyl
2-propynyl oxalate, ethyl 2-propynyl oxalate, and 2-butyne-1,4-diyl
dimethanesulfonate are preferred; and one or more selected from
2-propynyl methanesulfonate, 2-propynyl vinylsulfonate, 2-propynyl
2-(methanesulfonyloxy)propionate, di(2-propynyl) oxalate, and
2-butyne-1,4-diyl dimethanesulfonate are more preferred.
[0153] It is preferred to use (E) the cyclic or linear S.dbd.O
group-containing compound selected from sultones, cyclic sulfites,
sulfonic acid esters, and vinylsulfones, (provided that triple
bond-containing compounds are not included).
[0154] As the cyclic S.dbd.O group-containing compound, there are
suitably exemplified one or more selected from sultones, such as
1,3-propanesultone, 1,3-butanesultone, 1,4-butanesultone,
2,4-butanesultone, 1,3-propenesultone,
2,2-dioxide-1,2-oxathiolane-4-yl acetate,
5,5-dimethyl-1,2-oxathiolane-4-one 2,2-dioxide, etc.; sulfonic acid
esters, such as methylene methanedisulfonate, etc.; and cyclic
sulfites, such as ethylene sulfite,
4-(methylsulfonylmethyl)-1,3,2-dioxathiolane 2-oxide, etc.
[0155] As the linear S.dbd.O group-containing compound, there are
suitably exemplified one or more selected from butane-2,3-diyl
dimethanesulfonate, butane-1,4-diyl dimethanesulfonate, dimethyl
methanedisulfonate, pentafluorophenyl methanesulfonate,
divinylsulfone, and bis(2-vinylsulfonylethyl) ether.
[0156] Of the aforementioned cyclic or linear S.dbd.O
group-containing compounds, one or more selected from
1,3-propanesultone, 1,4-butanesultone, 2,4-butanesultone,
2,2-dioxide-1,2-oxathiolane-4-yl acetate,
5,5-dimethyl-1,2-oxathiolane-4-one 2,2-dioxide, butane-2,3-diyl
dimethanesulfonate, pentafluorophenyl methanesulfonate, and
divinylsulfone are more preferred.
[0157] As (F) the cyclic acetal compound, 1,3-dioxolane and
1,3-dioxane are preferred, and 1,3-dioxane is more preferred.
[0158] As (G) the phosphorus-containing compound,
tris(2,2,2-trifluoroethyl) phosphate,
tris(1,1,1,3,3,3-hexafluoropropan-2-yl) phosphate, methyl
2-(dimethylphosphoryl) acetate, ethyl
2-(dimethylphosphoryl)acetate, methyl 2-(diethylphosphoryl)
acetate, ethyl 2-(diethylphosphoryl) acetate, 2-propynyl
2-(dimethylphosphoryl)acetate, 2-propynyl
2-(diethylphosphoryl)acetate, methyl 2-(dimethoxyphosphoryl)
acetate, ethyl 2-(dimethoxyphosphoryl)acetate, methyl
2-(diethoxyphosphoryl)acetate, ethyl 2-(diethoxyphosphoryl)
acetate, 2-propynyl 2-(dimethoxyphosphoryl)acetate, and 2-propynyl
2-(diethoxyphosphoryl)acetate are preferred; and
tris(2,2,2-trifluoroethyl) phosphate,
tris(1,1,1,3,3,3-hexafluoropropan-2-yl) phosphate, ethyl
2-(diethylphosphoryl) acetate, 2-propynyl 2-(dimethylphosphoryl)
acetate, 2-propynyl 2-(diethylphosphoryl)acetate, ethyl
2-(diethoxyphosphoryl)acetate, 2-propynyl 2-(dimethoxyphosphoryl)
acetate, and 2-propynyl 2-(diethoxyphosphoryl) acetate are more
preferred.
[0159] As (H) the cyclic acid anhydride, succinic anhydride, maleic
anhydride, and 3-allylsuccinic anhydride are preferred, and
succinic anhydride and 3-allylsuccinic anhydride are more
preferred.
[0160] As (I) the cyclic phosphazene compound, cyclic phosphazene
compounds, such as methoxypentafluorocyclotriphosphazene,
ethoxypentafluorocyclotriphosphazene,
phenoxypentafluorocyclotriphosphazene, etc., are preferred, and
methoxypentafluorocyclotriphosphazene and
ethoxypentafluorocyclotriphosphazene are more preferred.
[0161] A content of each of the aforementioned additives (D) to (I)
is preferably 0.001 to 5% by mass in the nonaqueous electrolytic
solution. When the content falls within this range, a surface film
is sufficiently formed without causing an excessive increase of the
thickness, and stability of the surface film at a high temperature
is much more improved. The content is more preferably 0.01% by mass
or more, and still more preferably 0.1% by mass or more in the
nonaqueous electrolytic solution, and an upper limited thereof is
more preferably 3% by mass or less, and still more preferably 2% by
mass or less.
[0162] For the purpose of much more improving stability of a
surface film at a high temperature, it is preferred that at least
one selected from lithium salts having an oxalate skeleton, lithium
salts having a phosphate skeleton, and lithium salts having an
S.dbd.O group is included in the nonaqueous electrolytic
solution.
[0163] As specific examples of the lithium salt, there are suitably
exemplified at least one lithium salt having an oxalate skeleton,
which is selected from lithium bis(oxalate)borate (LiBOB), lithium
difluoro(oxalate)borate (LiDFOB), lithium
tetrafluoro(oxalate)phosphate (LiTFOP), and lithium
difluorobis(oxalate)phosphate (LiDFOP); a lithium salt having a
phosphate skeleton, such as LiPO.sub.2F.sub.2, Li.sub.2PO.sub.3F,
etc.; and at least one lithium salt having an S.dbd.O group, which
is selected from lithium trifluoro((methanesulfonyl)oxy)borate
(LiTFMSB), lithium pentafluoro((methanesulfonyl)oxy)phosphate
(LiPFMSP), lithium methyl sulfate (LMS), lithium ethyl sulfate
(LES), lithium 2,2,2-trifluoroethyl sulfate (LFES), and
FSO.sub.3Li.
[0164] Among those, it is more preferred that a lithium salt
selected from LiBOB, LiDFOB, LiTFOP, LiDFOP, LiPO.sub.2F.sub.2,
LiTFMSB, LMS, LES, LFES, and FSO.sub.3Li is included.
[0165] A total content of at least one selected from lithium salts
having an oxalate skeleton, lithium salts having a phosphate
skeleton, and lithium salts having an S.dbd.O group, in particular
at least one lithium salt selected from LiBOB, LiDFOB, LiTFOP,
LiDFOP, LiPO.sub.2F.sub.2, Li.sub.2PO.sub.3F, LiTFMSB, LiPFMSP,
LMS, LES, LFES, and FSO.sub.3Li, is preferably 0.001 to 10% by mass
in the nonaqueous electrolytic solution. When the content is 10% by
mass or less, there is less concern that a surface film is
excessively formed on an electrode, so that the storage
characteristics are worsened, and when it is 0.001% by mass or
more, the formation of a surface film is sufficient, and in the
case of using a battery at a high temperature and at a high
voltage, an improving effect of the characteristics is enhanced.
The content is preferably 0.05% by mass or more, more preferably
0.1% by mass or more, and still more preferably 0.3% by mass or
more in the nonaqueous electrolytic solution. An upper limit
thereof is preferably 5% by mass or less, more preferably 3% by
mass or less, and especially preferably 2% by mass or less.
(Lithium Salt)
[0166] As the electrolyte salt which is used in the present
invention, there are suitably exemplified the following lithium
salts.
[0167] As the lithium salt, there are suitably exemplified
inorganic lithium salts, such as LiPF.sub.6, LiBF.sub.4,
LiClO.sub.4, etc.; linear fluoroalkyl group-containing lithium
salts, such as LiN(SO.sub.2F).sub.2, LiN(SO.sub.2CF.sub.3).sub.2,
LiN(SO.sub.2C.sub.2F.sub.5).sub.2, LiCF.sub.3SO.sub.3,
LiC(SO.sub.2CF.sub.3).sub.3, LiPF.sub.4(CF.sub.3).sub.2,
LiPF.sub.3(C.sub.2F.sub.5).sub.3, LiPF.sub.3(CF.sub.3).sub.3,
LiPF.sub.3(iso-C.sub.3F.sub.7).sub.3,
LiPF.sub.5(iso-C.sub.3F.sub.7), etc.; and cyclic fluoroalkylene
chain-containing lithium salts, such as
(CF.sub.2).sub.2(SO.sub.2).sub.2NLi,
(CF.sub.2).sub.3(SO.sub.2).sub.2NLi, etc.; and the like. At least
one lithium salt selected from these lithium salts is suitably
exemplified, and one or more thereof may be solely or in
admixture.
[0168] Among those, one or more selected from LiPF.sub.6,
LiBF.sub.4, LiN(SO.sub.2CF.sub.3).sub.2,
LiN(SO.sub.2C.sub.2F.sub.5).sub.2, and LiN(SO.sub.2F).sub.2 are
preferred, and it is most preferred to use LiPF.sub.6.
[0169] In general, a concentration of the lithium salt is
preferably 0.3 M or more, more preferably 0.7 M or more, and still
more preferably 1.1 M or more relative to the nonaqueous solvent.
An upper limit thereof is preferably 2.5 M or less, more preferably
2.0 M or less, and still more preferably 1.6 M or less.
[0170] As for a suitable combination of these lithium salts, the
case of including LiPF.sub.6 and further including at least one
lithium salt selected from LiBF.sub.4. LiN(SO.sub.2CF.sub.3).sub.2,
and LiN(SO.sub.2F).sub.2 in the nonaqueous electrolytic solution is
preferred.
[0171] When a proportion of the lithium salt other than LiPF.sub.6
occupying in the nonaqueous solvent is 0.001 M or more, an
improving effect of the electrochemical characteristics in the case
of using the battery at a high temperature is liable to be
exhibited, and when it is 1.0 M or less, there is less concern that
the improving effect of the electrochemical characteristics in the
case of using the battery at a high temperature is worsened, and
hence, such is preferred. The proportion is preferably 0.01 M or
more, especially preferably 0.03 M or more, and most preferably
0.04 M or more. An upper limit thereof is preferably 0.8 M or less,
more preferably 0.6 M or less, and especially preferably 0.4 M or
less.
[Production of Nonaqueous Electrolytic Solution]
[0172] The nonaqueous electrolytic solution of the present
invention may be obtained, for example, by mixing the
aforementioned nonaqueous solvent, adding the aforementioned
electrolyte salt thereto, and further adding the carboxylic acid
ester compound represented by the foregoing general formula (I), in
particular the carboxylic acid ester compound represented by the
foregoing general formula (I-1), (I-2), or (I-3) to the resulting
nonaqueous electrolytic solution.
[0173] At this time, the nonaqueous solvent to be used and the
compounds to be added to the nonaqueous electrolytic solution are
preferably purified in advance to decrease impurities as far as
possible within the range where the productivity is not remarkably
worsened.
[0174] The nonaqueous electrolytic solution of the present
invention may be used in first to fourth energy storage devices
shown below, in which the nonaqueous electrolytic solution may be
used as the nonaqueous electrolyte not only in the form of a liquid
but also in the form of gel. Furthermore, the nonaqueous
electrolytic solution of the present invention may also be used for
a solid polymer electrolyte. Above all, the nonaqueous electrolytic
solution is preferably used in the first energy storage device
using a lithium salt as the electrolyte salt (namely, for a lithium
battery) or in the fourth energy storage device (namely, for a
lithium ion capacitor), more preferably used in a lithium battery,
and still more preferably used in a lithium secondary battery.
[First Storage Device (Lithium Battery)]
[0175] The lithium battery as referred to in the present
specification is a generic name for a lithium primary battery and a
lithium secondary battery. In the present specification, the term
"lithium secondary battery" is used as a concept also including a
so-called lithium ion secondary battery. The lithium battery of the
present invention includes a positive electrode, a negative
electrode, and the aforementioned nonaqueous electrolytic solution
having an electrolyte salt dissolved in a nonaqueous solvent. Other
constitutional members than the nonaqueous electrolytic solution,
such as the positive electrode, the negative electrode, etc., may
be used without being particularly limited.
[0176] For example, examples of a positive electrode active
material used for a lithium secondary battery include a complex
metal oxide containing lithium and one or more selected from
cobalt, manganese, and nickel. These positive electrode active
materials may be used solely or in combination of two or more
thereof.
[0177] Examples of the lithium complex metal oxide include one or
more selected from LiCoO.sub.2, LiMn.sub.2O.sub.4, LiNiO.sub.2,
LiCo.sub.1-xNixO.sub.2 (0.01<x<1),
LiCo.sub.1/3Ni.sub.1/3Mn.sub.1/3O.sub.2,
LiNi.sub.1/2Mn.sub.3/2O.sub.4, and LiCo.sub.0.98Mg.sub.0.02O.sub.2.
These materials may be used as a combination, such as a combination
of LiCoO.sub.2 and LiMn.sub.2O.sub.4, a combination of LiCoO.sub.2
and LiNiO.sub.2, and a combination of LiMn.sub.2O.sub.4 and
LiNiO.sub.2.
[0178] For improving the safety on overcharging and the cycle
characteristics, and for enabling the use at a charge potential of
4.3 V or more, a part of the lithium complex metal oxide may be
substituted with other elements. For example, a part of cobalt,
manganese, or nickel may be substituted with at least one element
selected from Sn, Mg, Fe, Ti, Al, Zr, Cr, V, Ga, Zn, Cu, Bi, Mo,
and La, a part of O may be substituted with S or F, or the oxide
may be coated with a compound containing any of such other
elements.
[0179] Among those, a lithium complex metal oxide capable of being
used at a charge potential of the positive electrode in a
fully-charged state of 4.3 V or more based on Li, such as
LiCoO.sub.2, LiMn.sub.2O.sub.4, and LiNiO.sub.2, is preferred; and
a lithium complex metal oxide capable of being used at 4.4 V or
more, such as LiCo.sub.1-xM.sub.xO.sub.2 (wherein M represents one
or more elements selected from Sn, Mg, Fe, Ti, Al, Zr, Cr, V, Ga,
Zn, and Cu, and 0.001.ltoreq.x.ltoreq.0.05),
LiCo.sub.1/3Ni.sub.1/3Mn.sub.1/3O.sub.2,
LiNi.sub.1/2Mn.sub.3/2O.sub.4, and a solid solution of
Li.sub.2MnO.sub.3 and LiMO.sub.2 (wherein M represents a transition
metal, such as Co, Ni, Mn, Fe, etc.), is more preferred. The use of
the lithium complex metal oxide capable of acting at a high charge
voltage is liable to worsen the electrochemical characteristics
particularly in a broad temperature range due to the reaction with
the electrolytic solution on charging, but in the lithium secondary
battery according to the present invention, worsening of the
electrochemical characteristics can be inhibited. In particular, a
battery with a positive electrode containing Mn tends to have an
increased resistance due to elution of Mn ions from the positive
electrode, thereby providing the tendency of worsening the
electrochemical characteristics in a broad temperature range.
However, the lithium secondary battery according to the present
invention is preferred because worsening of the electrochemical
characteristics can be inhibited.
[0180] Furthermore, a lithium-containing olivine-type phosphate may
also be used as the positive electrode active material. In
particular, a lithium-containing olivine-type phosphate including
one or more selected from iron, cobalt, nickel, and manganese is
preferred. As specific examples thereof, there are exemplified one
or more selected from LiFePO.sub.4, LiCoPO.sub.4, LiNiPO.sub.4, and
LiMnPO.sub.4. A part of such a lithium-containing olivine-type
phosphate may be substituted with other element. A part of iron,
cobalt, nickel, or manganese may be substituted with one or more
elements selected from Co, Mn, Ni, Mg, Al, B, Ti, V, Nb, Cu, Zn,
Mo, Ca, Sr, W, Zr, and the like, or the phosphate may be coated
with a compound containing any of these other elements or with a
carbon material. Among those, LiFePO.sub.4 and LiMnPO.sub.4 are
preferred. The lithium-containing olivine-type phosphate may also
be used, for example, in admixture with the aforementioned positive
electrode active material.
[0181] Examples of the positive electrode for a lithium primary
battery include oxides or chalcogen compounds of one or more metal
elements, such as CuO, Cu.sub.2O, Ag.sub.2O, Ag.sub.2CrO.sub.4,
CuS, CuSO.sub.4, TiO.sub.2, TiS.sub.2, SiO.sub.2, SnO,
V.sub.2O.sub.5, V.sub.6O.sub.12, VO.sub.x, Nb.sub.2O.sub.5,
Bi.sub.2O.sub.3, Bi.sub.2Pb.sub.2O.sub.5, Sb.sub.2O.sub.3,
CrO.sub.3, Cr.sub.2O.sub.3, MoO.sub.3, WO.sub.3, SeO.sub.2,
MnO.sub.2, Mn.sub.2O.sub.3, Fe.sub.2O.sub.3, FeO, Fe.sub.3O.sub.4,
Ni.sub.2O.sub.3, NiO, CoO.sub.3, CoO, and the like; a sulfur
compound, such as SO.sub.2, SOCl.sub.2, etc.; and a carbon fluoride
(graphite fluoride) represented by a general formula
(CF.sub.x).sub.n. Among those, MnO.sub.2, V.sub.2O.sub.5, graphite
fluoride, and the like are preferred.
[0182] In the case where when 10 g of the aforementioned positive
electrode active material is dispersed in 100 mL of distilled
water, a pH of a supernatant thereof is 10.0 to 12.5, the improving
effect of the electrochemical characteristics in a much broader
temperature range is liable to be obtained, and hence, such is
preferred. The case where the pH is 10.5 to 12.0 is more
preferred.
[0183] In the case where Ni is included as an element in the
positive electrode, the content of impurities, such as LiOH, etc.,
in the positive electrode active material tends to increase, and
the improving effect of the electrochemical characteristics in a
much broader temperature range is liable to be obtained, and hence,
such is preferred. The case where an atomic concentration of Ni in
the positive electrode active material is 5 to 25 atomic % is more
preferred, and the case where the atomic concentration of Ni is 8
to 21 atomic % is especially preferred.
[0184] An electroconductive agent of the positive electrode is not
particularly limited as far as it is an electron-conductive
material that does not undergo chemical change. Examples thereof
include graphite, such as natural graphite (e.g., flaky graphite,
etc.), artificial graphite, etc.; one or more carbon blacks
selected from acetylene black, Ketjen black, channel black, furnace
black, lamp black, and thermal black; and the like. The graphite
and the carbon black may be appropriately mixed and used. An amount
of the electroconductive agent added to a positive electrode
mixture is preferably from 1 to 10% by mass, and especially
preferably from 2 to 5% by mass.
[0185] The positive electrode can be produced in such a manner that
the positive electrode active material is mixed with an
electroconductive agent, such as acetylene black, carbon black,
etc., and then mixed with a binder, such as polytetrafluoroethylene
(PTFE), polyvinylidene fluoride (PVDF), a copolymer of styrene and
butadiene (SBR), a copolymer of acrylonitrile and butadiene (NBR),
carboxymethyl cellulose (CMC), an ethylene-propylene-diene
terpolymer, etc., to which is then added a high-boiling point
solvent, such as 1-methyl-2-pyrrolidone, etc., followed by kneading
to provide a positive electrode mixture, and the positive electrode
mixture is applied onto a collector, such as an aluminum foil, a
stainless steel-made lath plate, etc., dried, shaped under
pressure, and then heat-treated in vacuum at a temperature of about
50.degree. C. to 250.degree. C. for about 2 hours.
[0186] A density of the positive electrode except for the collector
is generally 1.5 g/cm.sup.3 or more, and for the purpose of further
increasing a capacity of the battery, the density is preferably 2
g/cm.sup.3 or more, more preferably 3 g/cm.sup.3 or more, and still
more preferably 3.6 g/cm.sup.3 or more. An upper limit thereof is
preferably 4 g/cm.sup.3 or less.
[0187] As a negative electrode active material for a lithium
secondary battery, one or more selected from lithium metal, a
lithium alloy, a carbon material capable of absorbing and releasing
lithium [e.g., graphitizable carbon, non-graphitizable carbon
having a spacing of a (002) plane of 0.37 nm or more, graphite
having a spacing of the (002) plane of 0.34 nm or less, etc.], tin
(elemental substance), a tin compound, silicon (elemental
substance), a silicon compound, and a lithium titanate compound,
such as Li.sub.4Ti.sub.5O.sub.12, etc., may be used.
[0188] Among the aforementioned negative electrode active
materials, in the ability of absorbing and releasing lithium ions,
the use of a high-crystalline carbon material, such as artificial
graphite, natural graphite, etc., is more preferred, and the use of
a carbon material having a graphite-type crystal structure in which
a lattice (002) spacing (d.sub.002) is 0.340 nm (nanometers) or
less, and especially from 0.335 to 0.337 nm, is still more
preferred. In particular, the use of artificial graphite particles
having a bulky structure containing plural flattened graphite fine
particles that are aggregated or bonded non-parallel to each other,
or graphite particles produced through a spheroidizing treatment of
flaky natural graphite particles by repeatedly applying a
mechanical action, such as a compression force, a friction force, a
shear force, etc., is preferred.
[0189] When a ratio I(110)/I(004) of a peak intensity I(110) of the
(110) plane to a peak intensity I(004) of the (004) plane of the
graphite crystal obtained through X-ray diffractometry of a
negative electrode sheet that is shaped under pressure to such an
extent that a density of the negative electrode except for the
collector is 1.5 g/cm.sup.3 or more, is 0.01 or more, the
electrochemical characteristics are improved in a much broader
temperature range, and hence, such is preferred. The ratio
I(110)/I(004) is more preferably 0.05 or more, and still more
preferably 0.1 or more. An upper limit of the ratio I(110)/I(004)
of the peak intensity is preferably 0.5 or less, and more
preferably 0.3 or less because there may be the case where the
crystallinity is worsened to lower the discharge capacity of the
battery due to an excessive treatment.
[0190] When the high-crystalline carbon material (core material) is
coated with a carbon material having lower crystallinity than the
core material, the electrochemical characteristics in a broad
temperature range become much more favorable, and hence, such is
preferred. The crystallinity of the carbon material in the coating
may be confirmed through TEM.
[0191] When the high-crystalline carbon material is used, there is
a tendency that it reacts with the nonaqueous electrolytic solution
on charging, thereby worsening the electrochemical characteristics
at a low temperature or a high temperature due to an increase of
interfacial resistance. However, in the lithium secondary battery
according to the present invention, the electrochemical
characteristics in a broad temperature range become favorable.
[0192] As the metal compound capable of absorbing and releasing
lithium as a negative electrode active material, there are suitably
exemplified compounds containing at least one metal element, such
as Si, Ge, Sn, Pb, P, Sb, Bi, Al, Ga, In, Ti, Mn, Fe, Co, Ni, Cu,
Zn, Ag, Mg, Sr, Ba, etc. The metal compound may be in any form
including an elemental substance, an alloy, an oxide, a nitride, a
sulfide, a boride, an alloy with lithium, and the like, and any of
an elemental substance, an alloy, an oxide, and an alloy with
lithium is preferred because the battery capacity can be increased.
Above all, compounds containing at least one element selected from
Si, Ge, and Sn are preferred, and compounds containing at least one
element selected from Si and Sn are more preferred because the
battery capacity can be increased.
[0193] The negative electrode can be produced in such a manner that
the same electroconductive agent, binder, and high-boiling point
solvent as in the production of the positive electrode as described
above are used and kneaded to provide a negative electrode mixture,
and the negative electrode mixture is then applied on a collector,
such as a copper foil, etc., dried, shaped under pressure, and then
heat-treated in vacuum at a temperature of about from 50.degree. C.
to 250.degree. C. for about 2 hours.
[0194] A density of the negative electrode except for the collector
is generally 1.1 g/cm.sup.3 or more, and for the purpose of further
increasing a capacity of the battery, the density is preferably 1.5
g/cm.sup.3 or more, and more preferably 1.7 g/cm.sup.3 or more. An
upper limit thereof is preferably 2 g/cm.sup.3 or less.
[0195] Examples of the negative electrode active material for a
lithium primary battery include lithium metal and a lithium
alloy.
[0196] The structure of the lithium battery is not particularly
limited, and may be a coin-type battery, a cylinder-type battery, a
prismatic battery, a laminate-type battery, or the like, each
having a single-layered or multi-layered separator.
[0197] The separator for the battery is not particularly limited,
and a single-layered or laminated micro-porous film of a
polyolefin, such as polypropylene, polyethylene, etc., a woven
fabric, a nonwoven fabric, and the like may be used.
[0198] The lithium secondary battery in the present invention has
excellent electrochemical characteristics in a broad temperature
range even when a final charging voltage is 4.2 V or more,
particularly 4.3 V or more, and furthermore, the characteristics
are favorable even at 4.4 V or more. A final discharging voltage
may be generally 2.8 V or more, and further 2.5 V or more, and the
final discharging voltage of the lithium secondary battery in the
present invention may be 2.0 V or more. An electric current is not
particularly limited, and in general, the battery may be used
within a range of from 0.1 to 30 C. The lithium battery in the
present invention may be charged and discharged at from -40 to
100.degree. C., and preferably from -10 to 80.degree. C.
[0199] In the present invention, as a countermeasure against the
increase in the internal pressure of the lithium battery, there may
also be adopted such a method that a safety valve is provided in a
battery cap, or a cutout is provided in a component, such as a
battery can, a gasket, etc. As a safety countermeasure for
prevention of overcharging, a circuit cut-off mechanism capable of
detecting the internal pressure of the battery to cut off the
current may be provided in the battery cap.
[Second Energy Storage Device (Electric Double Layer
Capacitor)]
[0200] The second energy storage device of the present invention is
an energy storage device including the nonaqueous electrolytic
solution of the present invention and storing energy by utilizing
an electric double layer capacitance in an interface between the
electrolytic solution and the electrode. One example of the present
invention is an electric double layer capacitor. A most typical
electrode active material which is used in this energy storage
device is active carbon. The double layer capacitance increases
substantially in proportion to a surface area.
[Third Energy Storage Device]
[0201] The third energy storage device of the present invention is
an energy storage device including the nonaqueous electrolytic
solution of the present invention and storing energy by utilizing a
doping/dedoping reaction of the electrode. Examples of the
electrode active material which is used in this energy storage
device include a metal oxide, such as ruthenium oxide, iridium
oxide, tungsten oxide, molybdenum oxide, copper oxide, etc., and a
Tn-conjugated polymer, such as polyacene, a polythiophene
derivative, etc. A capacitor using such an electrode active
material is capable of storing energy following the doping/dedoping
reaction of the electrode.
[Fourth Energy Storage Device (Lithium Ion Capacitor)]
[0202] The fourth energy storage device of the present invention is
an energy storage device including the nonaqueous electrolytic
solution of the present invention and storing energy by utilizing
intercalation of lithium ions into a carbon material, such as
graphite, etc., as the negative electrode. This energy storage
device is called a lithium ion capacitor (LIC). Examples of the
positive electrode include one utilizing an electric double layer
between an active carbon electrode and an electrolytic solution,
one utilizing a doping/dedoping reaction of a n-conjugated polymer
electrode, and the like. The electrolytic solution contains at
least a lithium salt, such as LiPF.sub.6, etc.
[0203] One of the carboxylic acid ester compounds as a novel
compound of the present invention is represented by the following
general formula (II).
##STR00087##
[0204] In the formula, each of R.sup.41 and R.sup.42 independently
represents a hydrogen atom, a halogen atom, an alkyl group having 1
to 6 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, a cycloalkyl group having 3 to 6
carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an
alkynyl group having 3 to 6 carbon atoms, an aralkyl group having 7
to 13 carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, an aryl group having 6 to 12
carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, or a --C(.dbd.O)--OR.sup.44 group,
and when R.sup.41 and R.sup.42 are each an alkyl group, then
R.sup.41 and R.sup.42 may be bonded to each other to form a ring
structure. R.sup.43 represents a hydrogen atom, a halogen atom, or
an alkyl group having 1 to 6 carbon atoms, and m represents 1 or
2.
[0205] When m is 1, then L.sup.4 and R.sup.44 may be the same as or
different from each other and represent a halogenated alkyl group
having 1 to 6 carbon atoms, in which at least one hydrogen atom is
substituted with a halogen atom, a halogenated cycloalkyl group
having 3 to 6 carbon atoms, in which at least one hydrogen atom is
substituted with a halogen atom, an alkenyl group having 2 to 6
carbon atoms, in which at least one hydrogen atom may be
substituted with a halogen atom, an alkynyl group having 3 to 6
carbon atoms, an alkoxyalkyl group having 3 to 6 carbon atoms, a
cyanoalkyl group having 2 to 6 carbon atoms, a halogenated aralkyl
group having 7 to 13 carbon atoms, in which at least one hydrogen
atom is substituted with a halogen atom, or a halogenated aryl
group having 6 to 12 carbon atoms, in which at least one hydrogen
atom is substituted with a halogen atom, and when m is 2, then
L.sup.4 represents an alkylene group having 2 to 6 carbon atoms, in
which at least one hydrogen atom is substituted with a halogen
atom, an alkenylene group having 4 to 8 carbon atoms, or an
alkynylene group having 4 to 8 carbon atoms, and R.sup.44 is the
same as described above, provided that when m is 1, then L.sup.4 is
not a 3-methyl-2-buten-1-yl group.
[0206] In the general formula (II), the substituents R.sup.41,
R.sup.42, and R.sup.43 are synonymous with R.sup.1, R.sup.2, and
R.sup.3 in the general formula (I), respectively.
[0207] m is corresponding to a part of n of the general formula (I)
and represents 1 or 2. Detailed thereof have already been explained
in the foregoing general formula (I), and hence, in this section,
the explanation is omitted in order to avoid overlapping. In this
case, the substituents R.sup.4 and L of the general formula (I) can
be designated as the substituents R.sup.44 and L.sup.4 of the
general formula (II), respectively.
[0208] Specific carboxylic ester compounds represented by the
foregoing general formula (II) are the same as the specific
compounds and preferred compounds described with respect to the
general formula (I), exclusive of the compounds having any one of
the structural formulae of 1 to 11, 56 to 58, 61 to 63, 64 to 68,
83, 87, 89, 91, 93, 95, 91, 97, 101, 103, 105, 107, 109, 111, 113,
115, 117, 119 to 121, 128 to 136, and 147 to 149.
[0209] The carboxylic acid ester compound represented by the
general formula (II) of the present invention may be synthesized by
the following two methods, but the present invention is not limited
to these production methods.
(a) Dehydration Condensation Method:
[0210] The carboxylic acid ester compound is obtained by subjecting
a carboxylic acid compound obtained by the method described in
WO2013/092011 and an alcohol compound to dehydration condensation
in a solvent or non-solvent in the presence of a dehydration
condensing agent.
(b) Acid Chloride Method:
[0211] The carboxylic acid ester compound is obtained by allowing
an acid chloride of a carboxylic acid compound to react with an
alcohol compound in a solvent in the presence or absence of a
base.
[0212] Another one of the carboxylic acid ester compounds as a
novel compound of the present invention is represented by the
following general formula (III).
##STR00088##
[0213] In the formula, each of R.sup.51 and R.sup.52 independently
represents a hydrogen atom, a halogen atom, an alkyl group having 1
to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms,
an alkenyl group having 2 to 6 carbon atoms, an alkynyl group
having 3 to 6 carbon atoms, an aralkyl group having 7 to 13 carbon
atoms, an aryl group having 6 to 12 carbon atoms, or a
--C(.dbd.O)--OR.sup.54 group, and when R.sup.51 and R.sup.52 are
each an alkyl group, then R.sup.51 and R.sup.52 may be bonded to
each other to form a ring structure. R.sup.53 represents a hydrogen
atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms,
and m represents 1 or 2.
[0214] When m is 1, then L.sup.5 and R.sup.54 may be the same as or
different from each other and represent an alkyl group having 1 to
6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, an
alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 3
to 6 carbon atoms, an alkoxyalkyl group having 2 to 6 carbon atoms,
a cyanoalkyl group having 2 to 6 carbon atoms, an aralkyl group
having 7 to 13 carbon atoms, or an aryl group having 6 to 12 carbon
atoms, and when m is 2, then L.sup.5 represents an alkylene group
having 2 to 8 carbon atoms, an alkenylene group having 4 to 8
carbon atoms, or an alkynylene group having 4 to 8 carbon atoms, at
least one hydrogen atom of L.sup.5 may be substituted with a
halogen atom, and R.sup.54 is the same as described above.
[0215] X.sup.3 represents an
--S(.dbd.O).sub.2--R.sup.55--S(.dbd.O).sub.2-- group, and R.sup.55
represents an alkylene group having 1 to 4 carbon atoms, in which
at least one hydrogen atom may be substituted with a halogen atom
or an alkyl group having 1 to 4 carbon atoms.
[0216] At least one hydrogen atom of the alkyl group having 1 to 6
carbon atoms, the cycloalkyl group having 3 to 6 carbon atoms, the
alkenyl group having 2 to 6 carbon atoms, the alkynyl group having
3 to 6 carbon atoms, the alkoxyalkyl group having 2 to 6 carbon
atoms, the cyanoalkyl group having 2 to 6 carbon atoms, the aralkyl
group having 7 to 13 carbon atoms, or the aryl group having 6 to 12
carbon atoms as R.sup.51, R.sup.52, R.sup.54, or L.sup.5, may be
substituted with a halogen atom.
[0217] Specific compounds represented by the foregoing general
formula (III) are the same as the description of specific compounds
and preferred description for the general formula (I).
[0218] The compound represented by the general formula (III) may be
synthesized by a method of allowing an alkanedisulfonyl dihalide
compound to react with a corresponding diol compound in a solvent
or non-solvent in the presence of a base, but the present invention
is not limited to such a method.
[0219] As for effects of the compound represented by the general
formula (III), for example, an effect as an additive for an energy
storage device shown in the following Examples, but the invention
is not limited thereto.
[0220] The compound represented by the general formula (III) is a
novel carboxylic acid ester compound, and in view of a special
structure thereof, it includes an application as an electrolyte,
and so on in the fields of general chemistry, particularly organic
chemistry, electrochemistry, biochemistry, and polymer
chemistry.
[0221] In consequence, the compound represented by the general
formula (III) is a useful compound as intermediate raw materials of
drugs, agricultural chemicals, electronic materials, polymer
materials, and the like, and also as electronic materials.
EXAMPLES
[0222] Synthesis Examples of the carboxylic acid ester compound
which is used in the present invention and Examples of the
electrolytic solution of the present invention are hereunder
described, but it should not be construed that the present
invention is limited to these Synthesis Examples and Examples.
Synthesis Example I-1 [Synthesis of 2-Propynyl
2-Oxo-1,3-dioxolane-4-carboxylate (Synthetic Compound 1)]
[0223] 7.1 g (0.054 mol) of 2-oxo-1,3-dioxolane-4-carboxylic acid,
30 mL of ethyl acetate, and 3.0 g (0.054 mol) of propargyl alcohol
were added at room temperature and then cooled to 10.degree. C. To
this solution, 12.4 g (0.065 mol) of
1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride was
added at 10 to 20.degree. C. over 10 minutes, followed by stirring
at room temperature for 3 hours. The reaction solution was washed
with water and extracted with ethyl acetate, and the solvent was
concentrated under reduced pressure. The resulting residue was
purified by means of silica gel column chromatography (elution with
ethyl acetate/hexane=1/2), thereby obtaining 4.9 g (yield: 53%) of
the targeted 2-propynyl 2-oxo-1,3-dioxolane-4-carboxylate.
[0224] The obtained 2-propynyl 2-oxo-1,3-dioxolane-4-carboxylate
was subjected to .sup.1H-NMR and melting point measurement, thereby
confirming its structure. The results are shown below.
[0225] .sup.1H-NMR (400 MHz, CDCl.sub.3): .delta.=5.14 (dd, J=5.4
Hz, 9.0 Hz, 1H), 6=4.86 (d, J=2.5 Hz, 2H), .delta.=4.71 (t, J=9.0
Hz, 1H), .delta.=4.56 (dd, J=5.4 Hz, 9.0 Hz, 1H), 2.58 (t, J=2.5
Hz, 1H)
[0226] Melting point: 35.degree. C.
Examples I-1 to 1-46 and Comparative Examples I-1 to I-3
[Production of Lithium Ion Secondary Battery]
[0227] 94% by mass of LiNi.sub.1/3Mn.sub.1/3Co.sub.1/3O.sub.2 and
3% by mass of acetylene black (electroconductive agent) were mixed
and then added to and mixed with a solution which had been prepared
by dissolving 3% by mass of polyvinylidene fluoride (binder) in
1-methyl-2-pyrrolidone in advance, thereby preparing a positive
electrode mixture paste. This positive electrode mixture paste was
applied onto one surface of an aluminum foil (collector), dried,
and treated under pressure, followed by cutting into a
predetermined size, thereby producing a positive electrode sheet in
a belt-like form. A density of the positive electrode except for
the collector was 3.6 g/cm.sup.3.
[0228] 10% by mass of silicon (elemental substance), 80% by mass of
artificial graphite (d.sub.002=0.335 nm, negative electrode active
material), and 5% by mass of acetylene black (electroconductive
agent) were mixed and then added to and mixed with a solution which
had been prepared by dissolving 5% by mass of polyvinylidene
fluoride (binder) in 1-methyl-2-pyrrolidone in advance, thereby
preparing a negative electrode mixture paste. This negative
electrode mixture paste was applied onto one surface of a copper
foil (collector), dried, and treated under pressure, followed by
cutting into a predetermined size, thereby producing a negative
electrode sheet. A density of the negative electrode except for the
collector was 1.5 g/cm.sup.3.
[0229] The electrode sheet was analyzed by X-ray diffractometry,
and a ratio [I(110)/I(004)] of the peak intensity I(110) of the
(110) plane to the peak intensity I(004) of the (004) plane of the
graphite crystal was 0.1.
[0230] The above-obtained positive electrode sheet, a micro-porous
polyethylene-made film separator and the above-obtained negative
electrode sheet were laminated in this order, and the nonaqueous
electrolytic solution having each of compositions shown in Tables 1
and 2 was added, thereby producing a laminate-type battery.
[Discharge Capacity Retention Rate after High-Temperature Charged
Storage]
<Initial Discharge Capacity>
[0231] In a thermostatic chamber at 25.degree. C., the
laminate-type battery produced by the aforementioned method was
charged up to a final voltage of 4.35 V with a constant current of
1 C and under a constant voltage for 3 hours and then discharged
down to a final voltage of 2.75 V with a constant current of 1 C,
thereby determining an initial discharge capacity.
<High-Temperature Charged Storage Test>
[0232] Subsequently, in a thermostatic chamber at 60.degree. C.,
this laminate-type battery was charged up to a final voltage of
4.35 V with a constant current of 1 C and under a constant voltage
for 3 hours, and then stored for 7 days while being kept at 4.35 V.
Thereafter, the battery was placed in a thermostatic chamber at
25.degree. C., and once discharged under a constant current of 1 C
to a final voltage of 2.75 V.
<Discharge Capacity after High-Temperature Charged
Storage>
[0233] Further thereafter, the discharge capacity after the
high-temperature charged storage was determined in the same manner
as in the measurement of the initial discharge capacity.
<Discharge Capacity Retention Rate after High-Temperature
Charged Storage>
[0234] A discharge capacity retention rate (%) after the
high-temperature charged storage was determined according to the
following equation.
Discharge capacity retention rate (%) after high-temperature
charged storage=(Discharge capacity after high-temperature charged
storage)/(Initial discharge capacity).times.100
[Evaluation of Gas Generation Amount after High-Temperature Charged
Storage]
[0235] A gas generation amount after the high-temperature charged
storage was measured by the Archimedean method. As for the gas
generation amount, a relative gas generation amount was evaluated
on the basis of defining the gas generation amount of Comparative
Example I-1 as 100%.
[0236] In addition, the production condition and battery
characteristics of each of the batteries are shown in Tables 1 to
4.
[0237] In Table 2, LiBOB (Example I-25) is lithium
bis(oxalate)borate, GBL (Example I-26) is .gamma.-butyrolactone,
and EA (Example I-27) is ethyl acetate.
TABLE-US-00001 TABLE 1 Compound represented by formula (I-1)
Composition of electrolyte salt Content in Discharge Composition of
nonaqueous nonaqueous capacity Gas generation electrolytic solution
electrolytic solution retention rate amount (volume ratio of
solvent) Kind (% by mass) (%) (%) Example I-1 Example I-2 Example
I-3 1.15M LiPF.sub.6 EC/DMC/MEC (30/40/30) 1.15M LiPF.sub.6 EC/MEC
(30/70) 1.15M LiPF.sub.6 EC/VC/DMC/MEC (29/1/40/30) ##STR00089## 1
1 0.05 80 77 72 55 58 62 Example I-4 1.15M LiPF.sub.6 0.1 76 58
EC/VC/DMC/MEC (29/1/40/30) Example I-5 1.15M LiPF.sub.6 0.5 80 55
EC/VC/DMC/MEC (29/1/40/30) Example I-6 1.15M LiPF.sub.6 1 82 52
EC/VC/DMC/MEC (29/1/40/30) Example I-7 1.15M LiPF.sub.6 3 76 57
EC/VC/DMC/MEC (29/1/40/30) Example I-8 1.15M LiPF.sub.6 5 72 63
EC/VC/DMC/MEC (29/1/40/30) Example I-9 1.15M LiPF.sub.6 10 70 65
EC/VC/DMC/MEC (29/1/40/30) Example I-10 Example I-11 1.15M
LiPF.sub.6 EC/VC/DMC/MEC (29/1/40/30) 1.15M LiPF.sub.6
EC/VC/DMC/MEC (29/1/40/30) ##STR00090## 20 30 68 66 70 75
TABLE-US-00002 TABLE 2 Composition of Compound represented by
formula (I-1) electrolyte salt Content in Discharge Composition
nonaqueous capacity Gas of nonaqueous electrolytic retention
generation electrolytic solution solution rate amount (volume ratio
of solvent) Kind (% by mass) (%) (%) Example I-12 1.15M LiPF.sub.6
EC/VC/DMC/MEC (29/1/40/30) ##STR00091## 1 77 56 Example I-13 1.15M
LiPF.sub.6 EC/VC/DMC/MEC (29/1/40/30) ##STR00092## 1 76 58 Example
I-14 1.15M LiPF.sub.6 EC/VC/DMC/MEC (29/1/40/30) ##STR00093## 1 75
59 Example I-15 1.15M LiPF.sub.6 EC/VC/DMC/MEC (29/1/40/30)
##STR00094## 1 78 54 Example I-16 1.15M LiPF.sub.6 EC/VC/DMC/MEC
(29/1/40/30) ##STR00095## 1 78 55 Example I-17 1.15M LiPF.sub.6
EC/VC/DMC/MEC (29/1/40/30) ##STR00096## 1 80 53 Example I-18 1.15M
LiPF.sub.6 EC/VC/DMC/MEC (29/1/40/30) ##STR00097## 1 80 54 Example
I-19 1.15M LiPF.sub.6 EC/VC/DMC/MEC (29/1/40/30) ##STR00098## 1 73
57 Example I-20 1.15M LiPF.sub.6 EC/VC/DMC/MEC (29/1/40/30)
##STR00099## 1 79 56 Example I-21 1.15M LiPF.sub.6 EC/VC/DMC/MEC
(29/1/40/30) ##STR00100## 1 81 53 Example I-22 1.15M LiPF.sub.6
EC/VC/DMC/MEC (29/1/40/30) ##STR00101## 1 74 55 Example I-23 1.15M
LiPF.sub.6 EC/VC/DMC/MEC (29/1/40/30) ##STR00102## 1 73 53 Example
I-24 1.15M LiPF.sub.6 EC/VC/DMC/MEC (29/1/40/30) ##STR00103## 1 80
54 Example I-25 1.15M LiPF.sub.6 + 0.05M LiBOB EC/FEC/VC/DMC/MEC
(19/10/1/40/30) ##STR00104## 1 84 52 Example I-26 1.15M LiPF.sub.6
+ 0.05M LiPO.sub.2F.sub.2 EC/VC/DMC/MEC/GBL (29/1/37/30/3)
##STR00105## 1 82 51 Example I-27 1.1M LiPF.sub.6 + 0.05M LES
EC/VC/DMC/MEC/EA (29/1/35/30/5) ##STR00106## 1 85 51
TABLE-US-00003 TABLE 3 Composition of Compound represented by
formula (I-1) electrolyte salt Content in Discharge Gas Composition
of nonaqueous nonaqueous capacity generation electrolytic solution
electrolytic solution retention rate amount (volume ratio of
solvent) Kind (% by mass) (%) (%) Example I-28 Example I-29 Example
I-30 1.15M LiPF.sub.6 EC/VC/DMC/MEC (29/1/40/30) 1.15M LiPF.sub.6
EC/VC/DMC/MEC (29/1/40/30) 1.15M LiPF.sub.6 EC/VC/DMC/MEC
(29/1/40/30) ##STR00107## 0.1 0.5 1 70 74 76 65 62 59 Example I-31
1.15M LiPF.sub.6 3 71 64 EC/VC/DMC/MEC (29/1/40/30) Example I-32
1.15M LiPF.sub.6 5 67 68 EC/VC/DMC/MEC (29/1/40/30) Example I-33
1.15M LiPF.sub.6 10 65 70 EC/VC/DMC/MEC (29/1/40/30) Example I-34
1.15M LiPF.sub.6 20 66 73 EC/VC/DMC/MEC (29/1/40/30) Example I-35
1.15M LiPF.sub.6 30 64 79 EC/VC/DMC/MEC (29/1/40/30) Example I-36
1.15M LiPF.sub.6 EC/VC/DMC/MEC (29/1/40/30) ##STR00108## 1 77 54
Example I-37 1.15M LiPF.sub.6 EC/VC/DMC/MEC (29/1/40/30)
##STR00109## 1 81 54 Comparative 1.15M LiPF.sub.6 None -- 56 100
Example I-1 EC/VC/DMC/MEC (29/1/40/30) Comparative Example I-2
1.15M LiPF.sub.6 EC/VC/DMC/MEC (29/1/40/30) ##STR00110## 1 55 101
Comparative Example I-3 1.15M LiPF.sub.6 EC/VC/DMC/MEC (29/1/40/30)
##STR00111## 1 61 98
TABLE-US-00004 TABLE 4 Composition of Compound represented by
electrolyte salt formula (I-1) Composition of Content in Discharge
nonaqueous nonaqueous capacity Gas electrolytic solution
electrolytic Group of Other additive (content in retention
generation (volume ratio of solution other nonaqueous electrolytic
rate amount solvent) Kind (% by mass) additive solution (% by
mass)) (%) (%) Example I-38 Example I-39 Example I-40 Example 1-41
Example I-42 1.15M LiPF.sub.6 EC/VC/DMC/MEC (29/1/40/30)
##STR00112## 1 A B C D E Adiponitrile (1) Cyclohexylbenzene (2) +
o-terphenyl (1) 1,6-Hexamethylene diisocyanate (1)
2-Butyne-1,4-diyl dimethanesulfonate (1) 5.5-Dimethyl-
1,2-oxathiolane-4-one 2,2-dioxide (0.5) 79 85 80 87 81 45 54 46 52
49 Example F 1,3-Dioxane (1) 82 44 I-43 Example G
Tris(2,2,2-trifluoroethyl) 81 46 I-44 phosphate (1.5) Example H
Succinic anhydride (1) 86 54 1-45 Example I Ethoxypentafluoro- 83
50 I-46 cyclotriphosphazene (1)
Examples I-47 and Comparative Example I-4
[0238] A positive electrode sheet was produced by using
LiNi.sub.1/2Mn.sub.3/2O.sub.4 (positive electrode active material)
in place of the positive electrode active material used in Example
I-1 and Comparative Example I-1. 94% by mass of
LiNi.sub.1/2Mn.sub.3/2O.sub.4 coated with amorphous carbon and 3%
by mass of acetylene black (electroconductive agent) were mixed and
then added to and mixed with a solution which had been prepared by
dissolving 3% by mass of polyvinylidene fluoride (binder) in
1-methyl-2-pyrrolidone in advance, thereby preparing a positive
electrode mixture paste. A laminate-type battery was produced and
subjected to battery evaluation in the same manners as in Example
I-1 and Comparative Example I-1, except that this positive
electrode mixture paste was applied onto one surface of an aluminum
foil (collector), dried, and treated under pressure, followed by
cutting into a predetermined size, thereby producing a positive
electrode sheet; and that in evaluating the battery, the final
charging voltage and the final discharging voltage were set to 4.9
V and 2.7 V, respectively. The results are shown in Table 5.
TABLE-US-00005 TABLE 5 Composition of Compound represented by
formula (I-1) electrolyte salt Content in Discharge Composition of
nonaqueous nonaqueous capacity Gas generation electrolytic solution
electrolytic solution retention rate amount (volume ratio of
solvent) Kind (% by mass) (%) (%) Example I-47 1.15M LiPF.sub.6
EC/FEC/MEC/DEC (20/10/45/25) ##STR00113## 1 77 62 Comparative None
-- 49 100 Example I-4
Example I-48 and Comparative Example I-5
[0239] A negative electrode sheet was produced by using lithium
titanate Li.sub.4Ti.sub.5O.sub.12 (negative electrode active
material) in place of the negative electrode active material used
in Example I-1 and Comparative Example I-1. 80% by mass of lithium
titanate Li.sub.4Ti.sub.5O.sub.12 and 15% by mass of acetylene
black (electroconductive agent) were mixed and then added to and
mixed with a solution which had been prepared by dissolving 5% by
mass of polyvinylidene fluoride (binder) in 1-methyl-2-pyrrolidone
in advance, thereby preparing a negative electrode mixture paste. A
laminate-type battery was produced and subjected to battery
evaluation in the same manners as in Example I-1 and Comparative
Example I-1, except that this negative electrode mixture paste was
applied onto one surface of a copper foil (collector), dried, and
treated under pressure, followed by cutting into a predetermined
size, thereby producing a negative electrode sheet; that in
evaluating the battery, the final charging voltage and the final
discharging voltage were set to 2.8 V and 1.2 V, respectively; and
that the composition of the nonaqueous electrolyte was changed to a
predetermined composition. The results are shown in Table 6.
TABLE-US-00006 [TABLE 6 Composition of Compound represented by
formula (I-1) electrolyte salt Content in Discharge Composition of
nonaqueous nonaqueous capacity Gas generation electrolytic solution
electrolytic solution retention rate amount (volume ratio of
solvent) Kind (% by mass) (%) (%) Example I-48 1.15M LiPF.sub.6
PC/DEC (30/70) ##STR00114## 1 89 42 Comparative None -- 79 100
Example I-5
[0240] All of the lithium secondary batteries of Examples I-1 to
1-46 as described above are improved in the storage characteristics
at a high temperature and at a high voltage and inhibited in the
gas generation amount, as compared with the lithium secondary
batteries of Comparative Example I-1 which is in the case of not
containing the compound represented by the general formula (I-1)
and Comparative Examples I-2 and I-3 which are in the case of
adding the compounds described in PTLs 1 and 2, respectively.
[0241] In the light of the above, it has become clear that the
effects brought in the case of using the energy storage device of
the present invention at a high voltage are peculiar effects
brought in the case where the nonaqueous electrolytic solution
contains the compound represented by the general formula (I-1).
[0242] In addition, from the comparison of Example I-47 with
Comparative Example I-4 in the case of using lithium nickel
manganate (LiN.sub.1/2Mn.sub.3/2O.sub.4) for the positive electrode
and also from the comparison of Example I-48 with Comparative
Example I-5 in the case of using lithium titanate
(Li.sub.4Ti.sub.5O.sub.12) for the negative electrode, the same
effects are brought.
[0243] In consequence, it is evident that the effects of the
present invention according to Embodiment 1 are not an effect
relying upon a specified positive electrode or negative
electrode.
[0244] Furthermore, the nonaqueous electrolytic solution containing
the compound represented by the general formula (I-1) of the
present invention also has an effect for improving the discharging
properties in the case of using a lithium primary battery at a high
voltage.
Examples II-1 to II-25 and Comparative Examples II-1 to II-4
[Production of Lithium Ion Secondary Battery]
[0245] 94% by mass of LiNi.sub.1/3Mn.sub.1/3Co.sub.1/3O.sub.2 and
3% by mass of acetylene black (electroconductive agent) were mixed
and then added to and mixed with a solution which had been prepared
by dissolving 3% by mass of polyvinylidene fluoride (binder) in
1-methyl-2-pyrrolidone in advance, thereby preparing a positive
electrode mixture paste. This positive electrode mixture paste was
applied onto one surface of an aluminum foil (collector), dried,
and treated under pressure, followed by cutting into a
predetermined size, thereby producing a positive electrode sheet in
a belt-like form. A density of the positive electrode except for
the collector was 3.6 g/cm.sup.3.
[0246] 10% by mass of silicon (elemental substance), 80% by mass of
artificial graphite (d.sub.002=0.335 nm, negative electrode active
material), and 5% by mass of acetylene black (electroconductive
agent) were mixed and then added to and mixed with a solution which
had been prepared by dissolving 5% by mass of polyvinylidene
fluoride (binder) in 1-methyl-2-pyrrolidone in advance, thereby
preparing a negative electrode mixture paste. This negative
electrode mixture paste was applied onto one surface of a copper
foil (collector), dried, and treated under pressure, followed by
cutting into a predetermined size, thereby producing a negative
electrode sheet. A density of the negative electrode except for the
collector was 1.5 g/cm.sup.3.
[0247] The electrode sheet was analyzed by X-ray diffractometry,
and a ratio [I(110)/I(004)] of the peak intensity I(110) of the
(110) plane to the peak intensity I(004) of the (004) plane of the
graphite crystal was 0.1.
[0248] The above-obtained positive electrode sheet, a micro-porous
polyethylene-made film separator and the above-obtained negative
electrode sheet were laminated in this order, and the nonaqueous
electrolytic solution having each of compositions shown in Tables 7
and 8 was added, thereby producing a laminate-type battery.
[Discharge Capacity Retention Rate after High-Temperature Charged
Storage]
<Initial Discharge Capacity>
[0249] In a thermostatic chamber at 25.degree. C., the
laminate-type battery produced by the aforementioned method was
charged up to a final voltage of 4.35 V with a constant current of
1 C and under a constant voltage for 3 hours and then discharged
down to a final voltage of 2.75 V with a constant current of 1 C,
thereby determining an initial discharge capacity.
<High-Temperature Charged Storage Test>
[0250] Subsequently, in a thermostatic chamber at 65.degree. C.,
this laminate-type battery was charged up to a final voltage of
4.35 V with a constant current of 1 C and under a constant voltage
for 3 hours, and then stored for 5 days while being kept at 4.35 V.
Thereafter, the battery was placed in a thermostatic chamber at
25.degree. C., and once discharged under a constant current of 1 C
to a final voltage of 2.75 V.
<Discharge Capacity after High-Temperature Charged
Storage>
[0251] Further thereafter, the discharge capacity after the
high-temperature charged storage was determined in the same manner
as in the measurement of the initial discharge capacity.
<Discharge Capacity Retention Rate after High-Temperature
Charged Storage>
[0252] A discharge capacity retention rate (%) after the
high-temperature charged storage was determined according to the
following equation.
Discharge capacity retention rate (%) after high-temperature
charged storage=(Discharge capacity after high-temperature charged
storage)/(Initial discharge capacity).times.100
[Evaluation of Gas Generation Amount after High-Temperature Charged
Storage]
[0253] A gas generation amount after the high-temperature charged
storage was measured by the Archimedean method. As for the gas
generation amount, a relative gas generation amount was evaluated
on the basis of defining the gas generation amount of Comparative
Example II-1 as 100%.
[0254] In addition, the production condition and battery
characteristics of each of the batteries are shown in Tables 7 and
8.
[0255] In Table 7, GBL (Example II-14) is .gamma.-butyrolactone,
MPiv (Example II-15) is methyl pivalate, and MP (Example II-16) is
methyl propionate.
TABLE-US-00007 TABLE 7 Compound represented by formula (I-2)
Composition of electrolyte salt Content in Discharge Composition of
nonaqueous nonaqueous capacity Gas generation electrolytic solution
electrolytic solution retention rate amount (volume ratio of
solvent) Kind (% by mass) (%) (%) Example II-1 Example II-2 Example
II-3 1M LiPF.sub.6 EC/PC/MEC/DEC (26/4/30/40) 1M LiPF.sub.6 EC/MEC
(30/70) 1M LiPF.sub.6 EC/PC/VC/MEC/DEC (20/9/1/30/40) ##STR00115##
1 1 0.01 71 67 63 64 67 72 Example II-4 1M LiPF.sub.6 0.1 72 64
EC/PC/VC/MEC/DEC (20/9/1/30/40) Example II-5 1M LiPF.sub.6 1 78 59
EC/PC/VC/MEC/DEC (20/9/1/30/40) Example II-6 1M LiPF.sub.6 4 73 57
EC/PC/VC/MEC/DEC (20/9/1/30/40) Example II-7 1M LiPF.sub.6
EC/PC/VC/MEC/DEC (20/9/1/30/40) ##STR00116## 1 75 61 Example II-8
1M LiPF.sub.6 EC/PC/VC/MEC/DEC (20/9/1/30/40) ##STR00117## 1 81 60
Example II-9 1M LiPF.sub.6 EC/PC/VC/MEC/DEC (20/9/1/30/40)
##STR00118## 1 77 59 Example II-10 1M LiPF.sub.6 EC/PC/VC/MEC/DEC
(20/9/1/30/40) ##STR00119## 1 79 58 Example II-11 1M LiPF.sub.6
EC/PC/VC/MEC/DEC (20/9/1/30/40) ##STR00120## 1 79 66 Example II-12
1M LiPF.sub.6 EC/PC/VC/MEC/DEC (20/9/1/30/40) ##STR00121## 1 76 63
Example II-13 Example II-14 Example II-15 Example II-16 1M
LiPF.sub.6 + 0.05M LiFOP EC/PC/FEC/VC/DEC/MEC (16/3/10/1/45/25) 1M
LiPF.sub.6 + 0.05M LiPO.sub.2F.sub.2 EC/PC/VC/DEC/MEC/GBL
(26/3/1/42/25/3) 1M LiPF.sub.6 + 0.05M LES EC/PC/VC/DEC/MEC/MPiv
(20/9/1/40/25/5) 0.70M LiPF.sub.6 + 0.35M FSI EC/PC/VC/DMC/MEC/MP
(20/9/1/40/25/5) ##STR00122## 1 1 1 1 81 80 83 84 58 55 54 56
TABLE-US-00008 TABLE 8 Compound represented by formula (I-2)
Composition of electrolyte salt Content in Discharge Composition of
nonaqueous nonaqueous capacity Gas generation electrolytic solution
electrolytic solution retention rate amount (volume ratio of
solvent) Kind (% by mass) (%) (%) Example II-17 Example II-18
Example II-19 1M LiPF.sub.6 EC/PC/MEC/DMC (20/10/30/40) 1M
LiPF.sub.6 EC/MEC (30/70) 1M LiPF.sub.6 EC/PC/VC/MEC/DEC
(20/9/1/30/40) ##STR00123## 1 1 0.01 68 65 61 68 70 73 Example
II-20 1M LiPF.sub.6 0.1 69 70 EC/PC/VC/MEC/DEC (20/9/1/30/40)
Example II-21 1M LiPF.sub.6 1 74 65 EC/PC/VC/MEC/DEC (20/9/1/30/40)
Example II-22 1M LiPF.sub.6 4 71 62 EC/PC/VC/MEC/DEC (20/9/1/30/40)
Example II-23 1M LiPF.sub.6 EC/PC/VC/MEC/DEC (20/9/1/30/40)
##STR00124## 1 73 68 Example II-24 1M LiPF.sub.6 EC/PC/VC/MEC/DEC
(20/9/1/30/40) ##STR00125## 1 72 70 Example II-25 1M LiPF.sub.6
EC/PC/VC/MEC/DEC (20/9/1/30/40) ##STR00126## 1 70 67 Comparative 1M
LiPF.sub.6 None 1 51 100 Example II-1 EC/PC/VC/MEC/DEC
(20/9/1/30/40) Comparative Example II-2 1M LiPF.sub.6
EC/PC/VC/MEC/DEC (20/9/1/30/40) ##STR00127## 1 59 88 Comparative
Example II-3 1M LiPF.sub.6 EC/PC/VC/MEC/DEC (20/9/1/30/40)
##STR00128## 1 54 92 Comparative Example II-4 1M LiPF.sub.6
EC/PC/VC/MEC/DEC (20/9/1/30/40) ##STR00129## 1 51 83
Examples II-26 and II-27 and Comparative Example II-5
[0256] A positive electrode sheet was produced by using
LiNi.sub.1/2Mn.sub.3/2O.sub.4 (positive electrode active material)
in place of the positive electrode active material used in Example
II-1 and Comparative Example II-1. 94% by mass of
LiNi.sub.1/2Mn.sub.3/2O.sub.4 coated with amorphous carbon and 3%
by mass of acetylene black (electroconductive agent) were mixed and
then added to and mixed with a solution which had been prepared by
dissolving 3% by mass of polyvinylidene fluoride (binder) in
1-methyl-2-pyrrolidone in advance, thereby preparing a positive
electrode mixture paste. A laminate-type battery was produced and
subjected to battery evaluation in the same manners as in Example
II-1 and Comparative Example II-1, except that this positive
electrode mixture paste was applied onto one surface of an aluminum
foil (collector), dried, and treated under pressure, followed by
cutting into a predetermined size, thereby producing a positive
electrode sheet; and that in evaluating the battery, the final
charging voltage and the final discharging voltage were set to 4.9
V and 2.7 V, respectively. The results are shown in Table 9.
[0257] In Table 9, FEC is 4-fluoro-1,3-dioxolan-2-one, and MTFEC is
methyl (2,2,2-trifluoroethyl)carbonate.
TABLE-US-00009 TABLE 9 Composition of Compound represented by
formula (I-2) electrolyte salt Content in Discharge Composition of
nonaqueous nonaqueous capacity Gas generation electrolytic solution
electrolytic solution retention rate amount (volume ratio of
solvent) Kind (% by mass) (%) (%) Example II-26 1M LiPF.sub.6
FEC/MTFEC (30/70) ##STR00130## 1 71 75 Example II-27 ##STR00131## 1
64 78 Comparative None -- 45 100 Example II-5
Examples II-28 and II-29 and Comparative Example II-6
[0258] A negative electrode sheet was produced by using lithium
titanate Li.sub.4Ti.sub.5O.sub.12 (negative electrode active
material) in place of the negative electrode active material used
in Example II-1 and Comparative Example II-1. 80% by mass of
lithium titanate Li.sub.4Ti.sub.5O.sub.12 and 15% by mass of
acetylene black (electroconductive agent) were mixed and then added
to and mixed with a solution which had been prepared by dissolving
5% by mass of polyvinylidene fluoride (binder) in
1-methyl-2-pyrrolidone in advance, thereby preparing a negative
electrode mixture paste. A laminate-type battery was produced and
subjected to battery evaluation in the same manners as in Example
II-1 and Comparative Example II-1, except that this negative
electrode mixture paste was applied onto one surface of a copper
foil (collector), dried, and treated under pressure, followed by
cutting into a predetermined size, thereby producing a negative
electrode sheet; and that in evaluating the battery, the final
charging voltage and the final discharging voltage were set to 2.8
V and 1.2 V, respectively; and that the composition of the
nonaqueous electrolyte was changed to a predetermined composition.
The results are shown in Table 10.
TABLE-US-00010 TABLE 10 Composition of Compound represented by
formula (I-2) electrolyte salt Content in Discharge Composition of
nonaqueous nonaqueous capacity Gas generation electrolytic solution
electrolytic solution retention rate amount (volume ratio of
solvent) Kind (% by mass) (%) (%) Example II-28 1M LiPF.sub.6
PC/DEC (30/70) ##STR00132## 1 87 64 Example II-29 ##STR00133## 1 82
68 Comparative None -- 74 100 Example II-6
[0259] All of the lithium secondary batteries of Examples II-1 to
II-25 as described above are improved in the storage
characteristics at a high temperature and at a high voltage and
inhibited in the gas generation amount, as compared with the
lithium secondary batteries of Comparative Example II-1 which is in
the case of not containing the compound represented by the general
formula (I-2) and Comparative Example II-2 which is in the case of
adding the compound described in PTL 4, respectively, the lithium
secondary battery of Comparative Example II-3 which is in the case
of adding the compound described in PTL 5, and the lithium
secondary battery of Comparative Example II-4 which is in the case
of adding the compound described in PTL 6.
[0260] In the light of the above, it has become clear that the
effects brought in the case of using the energy storage device of
the present invention at a high voltage are peculiar effects
brought in the case where the nonaqueous electrolytic solution
contains the compound represented by the general formula (I-2).
[0261] In addition, from the comparison of Examples II-26 and II-27
with Comparative Example II-5 in the case of using lithium nickel
manganate (LiNi.sub.1/2Mn.sub.3/2O.sub.4) for the positive
electrode and also from the comparison of Examples II-28 and II-29
with Comparative Example II-6 in the case of using lithium titanate
(Li.sub.4Ti.sub.5O.sub.12) for the negative electrode, the same
effects are brought.
[0262] In consequence, it is evident that the effects of the
present invention according to Embodiment 2 are not an effect
relying upon a specified positive electrode or negative
electrode.
[0263] Furthermore, the nonaqueous electrolytic solution containing
the compound represented by the general formula (I-2) of the
present invention also has an effect for improving the discharging
properties in the case of using a lithium primary battery at a high
voltage.
Synthesis Example III-1 [Synthesis of Dimethyl
1,5,2,4-Dioxadithiepane-6,7-dicarboxylate 2,2,4,4-Tetraoxide
(Synthetic Compound 3)]
[0264] 4.19 g (23.5 mmol) of dimethyl tartrate and 5.00 g (23.5
mmol) of methanedisulfonyl dichloride were dissolved in 140 mL of
ethyl acetate and then cooled to 15.degree. C. To this solution,
4.93 g (48.7 mmol) of triethylamine was added dropwise at 13 to
17.degree. C. over 10 minutes, followed by stirring at room
temperature for 3 hours. The produced salt was filtered off, the
solvent was concentrated under reduced pressure, and the resulting
residue was purified by means of silica gel column chromatography
(elution with ethyl acetate/hexane=1/5), thereby obtaining 1.72 g
(yield: 23%) of dimethyl 1,5,2,4-dioxadithiepane-6,7-dicarboxylate
2,2,4,4-tetraoxide as a white solid.
[0265] The obtained dimethyl
1,5,2,4-dioxadithiepane-6,7-dicarboxylate 2,2,4,4-tetraoxide was
subjected to 1H-NMR and melting point measurement. The results are
shown below. 1H-NMR (400 MHz, CDCl.sub.3): .delta.=5.73 (s, 2H),
.delta.=5.04 (s, 2H), .delta.=3.90 (s, 6H)
Examples III-1 to III-15 and Comparative Examples III-1 to
III-2
[Production of Lithium Ion Secondary Battery]
[0266] 94% by mass of LiCoO.sub.2 and 3% by mass of acetylene black
(electroconductive agent) were mixed and then added to and mixed
with a solution which had been prepared by dissolving 3% by mass of
polyvinylidene fluoride (binder) in 1-methyl-2-pyrrolidone in
advance, thereby preparing a positive electrode mixture paste. This
positive electrode mixture paste was applied onto one surface of an
aluminum foil (collector), dried, and treated under pressure,
followed by cutting into a predetermined size, thereby producing a
positive electrode sheet in a belt-like form. A density of the
positive electrode except for the collector was 3.6 g/cm.sup.3.
[0267] 10% by mass of silicon (elemental substance), 80% by mass of
artificial graphite (d.sub.002=0.335 nm, negative electrode active
material), and 5% by mass of acetylene black (electroconductive
agent) were mixed and then added to and mixed with a solution which
had been prepared by dissolving 5% by mass of polyvinylidene
fluoride (binder) in 1-methyl-2-pyrrolidone in advance, thereby
preparing a negative electrode mixture paste. This negative
electrode mixture paste was applied onto one surface of a copper
foil (collector), dried, and treated under pressure, followed by
cutting into a predetermined size, thereby producing a negative
electrode sheet. A density of the negative electrode except for the
collector was 1.5 g/cm.sup.3.
[0268] The electrode sheet was analyzed by X-ray diffractometry,
and a ratio [I(110)/I(004)] of the peak intensity I(110) of the
(110) plane to the peak intensity I(004) of the (004) plane of the
graphite crystal was 0.1.
[0269] The above-obtained positive electrode sheet, a micro-porous
polyethylene-made film separator and the above-obtained negative
electrode sheet were laminated in this order, and the nonaqueous
electrolytic solution having each of compositions shown in Tables
11 and 12 was added, thereby producing a laminate-type battery.
[Discharge Capacity Retention Rate after High-Temperature Charged
Storage]
<Initial Discharge Capacity>
[0270] In a thermostatic chamber at 25.degree. C., the
laminate-type battery produced by the aforementioned method was
charged up to a final voltage of 4.35 V with a constant current of
1 C and under a constant voltage for 3 hours and then discharged
down to a final voltage of 2.75 V with a constant current of 1 C,
thereby determining an initial discharge capacity.
<High-Temperature Charged Storage Test>
[0271] Subsequently, in a thermostatic chamber at 55.degree. C.,
this laminate-type battery was charged up to a final voltage of
4.35 V with a constant current of 1 C and under a constant voltage
for 3 hours, and then stored for 10 days while being kept at 4.35
V. Thereafter, the battery was placed in a thermostatic chamber at
25.degree. C., and once discharged under a constant current of 1 C
to a final voltage of 2.75 V.
<Discharge Capacity after High-Temperature Charged
Storage>
[0272] Further thereafter, the discharge capacity after the
high-temperature charged storage was determined in the same manner
as in the measurement of the initial discharge capacity.
<Discharge Capacity Retention Rate after High-Temperature
Charged Storage>
[0273] A discharge capacity retention rate (%) after the
high-temperature charged storage was determined according to the
following equation.
Discharge capacity retention rate (%) after high-temperature
charged storage=(Discharge capacity after high-temperature charged
storage)/(Initial discharge capacity).times.100
[Evaluation of Gas Generation Amount after High-Temperature Charged
Storage]
[0274] A gas generation amount after the high-temperature charged
storage was measured by the Archimedean method. As for the gas
generation amount, a relative gas generation amount was evaluated
on the basis of defining the gas generation amount of Comparative
Example III-1 as 100%.
[0275] In addition, the production condition and battery
characteristics of each of the batteries are shown in Tables 11 to
12.
TABLE-US-00011 TABLE 11 Compound represented by formula (I-3)
Composition of electrolyte salt Content in Discharge Gas
Composition of nonaqueous nonaqueous capacity generation
electrolytic solution electrolytic solution retention rate amount
(volume ratio of solvent) Kind (% by mass) (%) (%) Example III-1
Example III-2 Example III-3 Example III-4 1.2M LiPF.sub.6
EC/DMC/MEC (30/45/25) 1.2M LiPF.sub.6 EC/MEC (30/70) 1.2M
LiPF.sub.6 EC/VC/DMC/MEC (29/1/45/25) 1.2M LiPF.sub.6 EC/VC/DMC/MEC
(29/1/45/25) ##STR00134## 1 1 0.005 0.1 73 71 66 75 62 64 65 56
Example III-5 1.2M LiPF.sub.6 1 81 51 EC/VC/DMC/MEC (29/1/45/25)
Example III-6 1.2M LiPF.sub.6 3 75 55 EC/VC/DMC/MEC (29/1/45/25)
Example III-7 1.2M LiPF.sub.6 6 69 60 EC/VC/DMC/MEC (29/1/45/25)
Example III-8 1.2M LiPF.sub.6 EC/VC/DMC/MEC (29/1/45/25)
##STR00135## 1 77 53 Example III-9 1.2M LiPF.sub.6 EC/VC/DMC/MEC
(29/1/45/25) ##STR00136## 1 83 53 Example III-10 1.2M LiPF.sub.6
EC/VC/DMC/MEC (29/1/45/25) ##STR00137## 1 80 51 Example III-11 1.2M
LiPF.sub.6 EC/VC/DMC/MEC (29/1/45/25) ##STR00138## 1 81 53
TABLE-US-00012 TABLE 12 Composition of Compound represented by
formula (I-3) electrolyte salt Content in Discharge Gas Composition
of nonaqueous nonaqueous capacity generation electrolytic solution
electrolytic solution retention rate amount (volume ratio of
solvent) Kind (% by mass) (%) (%) Example III-8 1.2M LiPF.sub.6
EC/VC/DMC/MEC (29/1/45/25) ##STR00139## 1 77 53 Example III-9 1.2M
LiPF.sub.6 EC/VC/DMC/MEC (29/1/45/25) ##STR00140## 1 83 53 Example
III-10 1.2M LiPF.sub.6 EC/VC/DMC/MEC (29/1/45/25) ##STR00141## 1 80
51 Example III-11 1.2M LiPF.sub.6 EC/VC/DMC/MEC (29/1/45/25)
##STR00142## 1 81 53 Example III-12 Example III-13 Example III-14
Example III-15 1.2M LiPF.sub.6 + 0.05M LiFOP EC/FEC/VC/DMC/MEC
(19/10/1/45/25) 1.2M LiPF.sub.6 + 0.05M LiPO.sub.2F.sub.2
EC/VC/DMC/MEC/GBL (29/1/42/25/3) 1.2M LiPF.sub.6 + 0.05M LES
EC/VC/DMC/MEC/EA (29/1/40/25/5) 0.7M LiPF.sub.6 + 0.55M FSI
EC/VC/DMC/MEC (29/1/45/25) ##STR00143## 1 1 1 1 83 82 85 84 53 50
49 46 Comparative 1.2M LiPF.sub.6 None -- 54 100 Example III-1
EC/VC/DMC/MEC (29/1/45/25) Comparative Example III-2 1.2M
LiPF.sub.6 EC/VC/DMC/MEC (29/1/45/25) ##STR00144## 1 60 85
Example III-16 and Comparative Example III-3
[0276] A positive electrode sheet was produced by using
LiNi.sub.1/2Mn.sub.3/2O.sub.4 (positive electrode active material)
in place of the positive electrode active material used in Example
III-1 and Comparative Example III-1. 94% by mass of
LiNi.sub.1/2Mn.sub.3/2O.sub.4 coated with amorphous carbon and 3%
by mass of acetylene black (electroconductive agent) were mixed and
then added to and mixed with a solution which had been prepared by
dissolving 3% by mass of polyvinylidene fluoride (binder) in
1-methyl-2-pyrrolidone in advance, thereby preparing a positive
electrode mixture paste. A laminate-type battery was produced and
subjected to battery evaluation in the same manners as in Example
III-1 and Comparative Example III-1, except that this positive
electrode mixture paste was applied onto one surface of an aluminum
foil (collector), dried, and treated under pressure, followed by
cutting into a predetermined size, thereby producing a positive
electrode sheet; and that in evaluating the battery, the final
charging voltage and the final discharging voltage were set to 4.9
V and 2.7 V, respectively. The results are shown in Table 13.
TABLE-US-00013 TABLE 13 Composition of Compound represented by
formula (I-3) electrolyte salt Content in Discharge Composition of
nonaqueous nonaqueous capacity Gas generation electrolytic solution
electrolytic solution retention rate amount (volume ratio of
solvent) Kind (% by mass) (%) (%) Example III-16 1.2M LiPF.sub.6
EC/FEC/MEC/DEC (20/10/40/30) ##STR00145## 1 77 68 Comparative None
-- 51 100 Example III-3
Example III-17 and Comparative Example III-4
[0277] A negative electrode sheet was produced by using lithium
titanate Li.sub.4Ti.sub.5O.sub.12 (negative electrode active
material) in place of the negative electrode active material used
in Example III-1 and Comparative Example III-1. 80% by mass of
lithium titanate Li.sub.4Ti.sub.5O.sub.12 and 15% by mass of
acetylene black (electroconductive agent) were mixed and then added
to and mixed with a solution which had been prepared by dissolving
5% by mass of polyvinylidene fluoride (binder) in
1-methyl-2-pyrrolidone in advance, thereby preparing a negative
electrode mixture paste. A laminate-type battery was produced and
subjected to battery evaluation in the same manners as in Example
III-1 and Comparative Example III-1, except that this negative
electrode mixture paste was applied onto one surface of a copper
foil (collector), dried, and treated under pressure, followed by
cutting into a predetermined size, thereby producing a negative
electrode sheet; and that in evaluating the battery, the final
charging voltage and the final discharging voltage were set to 2.8
V and 1.2 V, respectively; and that the composition of the
nonaqueous electrolytic solution was changed to a predetermined
composition. The results are shown in Table 14.
TABLE-US-00014 TABLE 14 Composition of Compound represented by
formula (I-3) electrolyte salt Content in Discharge Composition of
nonaqueous nonaqueous capacity Gas generation electrolytic solution
electrolytic solution retention rate amount (volume ratio of
solvent) Kind (% by mass) (%) (%) Example III-17 1.15M LiPF.sub.6
PC/DEC (30/70) ##STR00146## 1 90 52 Comparative None -- 80 100
Example III-4
[0278] All of the lithium secondary batteries of Examples III-1 to
III-15 as described above are improved in the storage
characteristics at a high temperature and at a high voltage and
inhibited in the gas generation amount, as compared with the
lithium secondary batteries of Comparative Example III-1 which is
in the case of not containing the compound represented by the
general formula (I-3) and Comparative Example III-2 which is in the
case of adding the compound described in PTL 7, respectively.
[0279] In the light of the above, it has become clear that the
effects brought in the case of using the energy storage device of
the present invention at a high voltage are peculiar effects
brought in the case where the nonaqueous electrolytic solution
contains the compound represented by the general formula (I-3).
[0280] In addition, from the comparison of Example III-16 with
Comparative Example III-3 in the case of using lithium nickel
manganate (LiNi.sub.1/2Mn.sub.3/2O.sub.4) for the positive
electrode and also from the comparison of Example III-17 with
Comparative Example 111-4 in the case of using lithium titanate
(Li.sub.4Ti.sub.5O.sub.12) for the negative electrode, the same
effects are brought.
[0281] In consequence, it is evident that the effects of the
present invention according to Embodiment 3 are not an effect
relying upon a specified positive electrode or negative
electrode.
[0282] Furthermore, the nonaqueous electrolytic solution containing
the compound represented by the general formula (I-3) of the
present invention also has an effect for improving the discharging
properties in the case of using a lithium primary battery at a high
voltage.
INDUSTRIAL APPLICABILITY
[0283] The energy storage device using the nonaqueous electrolytic
solution of the present invention is useful as an energy storage
device, such as a lithium secondary battery, etc., having excellent
electrochemical characteristics in the case of using a battery at a
high temperature and at a high voltage.
* * * * *