U.S. patent application number 14/572683 was filed with the patent office on 2015-04-16 for accumulator material and accumulator device.
The applicant listed for this patent is PANASONIC CORPORATION. Invention is credited to Nobuhiko HOJO, Yu OHTSUKA, Takayuki SASAKI, Takahisa SHIMIZU, Takakazu YAMAMOTO, Tomoaki YANAGIDA.
Application Number | 20150104702 14/572683 |
Document ID | / |
Family ID | 41610201 |
Filed Date | 2015-04-16 |
United States Patent
Application |
20150104702 |
Kind Code |
A1 |
HOJO; Nobuhiko ; et
al. |
April 16, 2015 |
ACCUMULATOR MATERIAL AND ACCUMULATOR DEVICE
Abstract
An electricity storage device including a positive electrode, a
negative electrode, and an electrolytic solution located between
the positive electrode and the negative electrode. At least one of
the positive electrode 31 and the negative electrode contains an
electricity storage material containing a polymerization product
having a tetrachalcogenofulvalene structure in a repeat unit of a
main chain.
Inventors: |
HOJO; Nobuhiko; (Osaka,
JP) ; OHTSUKA; Yu; (Osaka, JP) ; YAMAMOTO;
Takakazu; (Kanagawa, JP) ; SHIMIZU; Takahisa;
(Kanagawa, JP) ; SASAKI; Takayuki; (Kanagawa,
JP) ; YANAGIDA; Tomoaki; (Kanagawa, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
PANASONIC CORPORATION |
Osaka |
|
JP |
|
|
Family ID: |
41610201 |
Appl. No.: |
14/572683 |
Filed: |
December 16, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12997516 |
Dec 10, 2010 |
8945769 |
|
|
PCT/JP2009/003648 |
Jul 31, 2009 |
|
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14572683 |
|
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Current U.S.
Class: |
429/188 ;
429/213; 526/256 |
Current CPC
Class: |
C08G 61/123 20130101;
H01M 4/60 20130101; H01M 4/602 20130101; Y02E 60/10 20130101; H01M
4/606 20130101; H01M 2220/20 20130101; C08G 2261/3422 20130101;
C08G 2261/148 20130101; H01M 2220/30 20130101; H01M 2300/0025
20130101; C08G 2261/344 20130101; H01M 10/0568 20130101; H01M
4/1399 20130101; H01M 10/052 20130101 |
Class at
Publication: |
429/188 ;
526/256; 429/213 |
International
Class: |
H01M 4/60 20060101
H01M004/60; H01M 10/052 20060101 H01M010/052; H01M 10/0568 20060101
H01M010/0568 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 31, 2008 |
JP |
2008-198502 |
Claims
1. An electricity storage device comprising: a positive electrode;
a negative electrode; and an electrolyte located between the
positive electrode and the negative electrode, wherein at least one
of the positive electrode and the negative electrode comprises an
electricity storage material containing a polymerization product
having a tetrachalcogenofulvalene structure in a repeat unit of a
main chain of the polymerization product, and the polymerization
product has a degree of polymerization of 4 or greater.
2. The electricity storage material of claim 1, wherein the main
chain of the polymerization product is formed of the
tetrachalcogenofulvalene structures directly bonded to each
other.
3. The electricity storage material of claim 2, wherein the
polymerization product is a copolymerization product of two or more
types of monomers which contain the tetrachalcogenofulvalene
structures having different substituents from each other.
4. The electricity storage material of claim 1, wherein the
polymerization product is a copolymerization product of a first
monomer and a second monomer, the first monomer containing at least
one selected from the group consisting of an acetylene structure
and a thiophene structure, and the second monomer containing the
tetrachalcogenofulvalene structure.
5. The electricity storage material of claim 1, wherein the
tetrachalcogenofulvalene structure is a tetrathiafulvalene
structure.
6. The electricity storage material of claim 1, wherein the
polymerization product has a degree of polymerization of 10 or
greater.
7. The electricity storage material of claim 1, wherein: the
tetrachalcogenofulvalene structure is represented by general
formula (1) shown below; and in general formula (1), X is an oxygen
atom, a sulfur atom, a selenium atom or a tellurium atom; two
selected from R1 through R4 each represent a bond with an adjacent
repeat unit; the other two are each independently at least one
selected from the group consisting of a chained saturated
hydrocarbon group, a chained unsaturated hydrocarbon group, a
cyclic saturated hydrocarbon group, a cyclic unsaturated
hydrocarbon group, a phenyl group, a hydrogen atom, a hydroxyl
group, a cyano group, an amino group, a nitro group and a nitroso
group; and the chained saturated hydrocarbon group, the chained
unsaturated hydrocarbon group, the cyclic saturated hydrocarbon
group and the cyclic unsaturated hydrocarbon group each contain at
least one selected from the group consisting of a carbon atom, an
oxygen atom, a nitrogen atom, a sulfur atom and a silicon atom.
##STR00044##
8. The electricity storage material of claim 2, wherein: the
polymerization product is represented by general formula (2) shown
below; and in general formula (2), X is an oxygen atom, a sulfur
atom, a selenium atom or a tellurium atom; R5 and R6 are each
independently at least one selected from the group consisting of a
chained saturated hydrocarbon group, a chained unsaturated
hydrocarbon group, a cyclic saturated hydrocarbon group, a cyclic
unsaturated hydrocarbon group, a phenyl group, a hydrogen atom, a
hydroxyl group, a cyano group, an amino group, a nitro group and a
nitroso group; and the chained saturated hydrocarbon group, the
chained unsaturated hydrocarbon group, the cyclic saturated
hydrocarbon group and the cyclic unsaturated hydrocarbon group each
contain at least one selected from the group consisting of a carbon
atom, an oxygen atom, a nitrogen atom, a sulfur atom and a silicon
atom. ##STR00045##
9. The electricity storage material of claim 8, wherein X is a
sulfur atom; and R5 and R6 are each a chained hydrocarbon group or
an aromatic group.
10. The electricity storage material of claim 8, wherein X is a
sulfur atom; and R5 and R6 are each C.sub.6H.sub.13,
C.sub.10H.sub.21, C.sub.8H.sub.17 or C.sub.6H.sub.5.
11. The electricity storage material of claim 3, wherein: the
polymerization product is a copolymerization product containing
repeat units represented by general formulas (3) and (4) shown
below; and in general formulas (3) and (4), X is an oxygen atom, a
sulfur atom, a selenium atom or a tellurium atom; R5 through R8 are
each independently at least one selected from the group consisting
of a chained saturated hydrocarbon group, a chained unsaturated
hydrocarbon group, a cyclic saturated hydrocarbon group, a cyclic
unsaturated hydrocarbon group, a phenyl group, a hydrogen atom, a
hydroxyl group, a cyano group, an amino group, a nitro group and a
nitroso group; the chained saturated hydrocarbon group, the chained
unsaturated hydrocarbon group, the cyclic saturated hydrocarbon
group and the cyclic unsaturated hydrocarbon group each contain at
least one selected from the group consisting of a carbon atom, an
oxygen atom, a nitrogen atom, a sulfur atom and a silicon atom; and
a combination of R5 and R6 is different from a combination of R7
and R8. ##STR00046##
12. The electricity storage material of claim 11, wherein X is a
sulfur atom; R5 and R6 are each a phenyl group; and R7 and R8 are
each a chained hydrocarbon group.
13. The electricity storage material of claim 4, wherein: the
polymerization product is represented by general formula (5) shown
below; in general formula (5), X is an oxygen atom, a sulfur atom,
a selenium atom or a tellurium atom; and R5 and R6 are each
independently at least one selected from the group consisting of a
chained saturated hydrocarbon group, a chained unsaturated
hydrocarbon group, a cyclic saturated hydrocarbon group, a cyclic
unsaturated hydrocarbon group, a phenyl group, a hydrogen atom, a
hydroxyl group, a cyano group, an amino group, a nitro group and a
nitroso group; the chained saturated hydrocarbon group, the chained
unsaturated hydrocarbon group, the cyclic saturated hydrocarbon
group and the cyclic unsaturated hydrocarbon group each contain at
least one selected from the group consisting of a carbon atom, an
oxygen atom, a nitrogen atom, a sulfur atom and a silicon atom; and
R9 is a chained unsaturated hydrocarbon group or a cyclic
unsaturated hydrocarbon group each containing an acetylene
structure, and contains at least one selected from the group
consisting of a carbon atom, an oxygen atom, a nitrogen atom, a
sulfur atom and a silicon atom. ##STR00047##
14. The electricity storage material of claim 13, wherein X is a
sulfur atom; R5 and R6 are each a phenyl group or a chained
hydrocarbon group; and R9 has a structure represented by chemical
formula (9) shown below. ##STR00048##
15. The electricity storage material of claim 4, wherein: the
polymerization product is represented by general formula (7) shown
below; in general formula (7), X is an oxygen atom, a sulfur atom,
a selenium atom or a tellurium atom; R5 and R6 are each
independently at least one selected from the group consisting of a
chained saturated hydrocarbon group, a chained unsaturated
hydrocarbon group, a cyclic saturated hydrocarbon group, a cyclic
unsaturated hydrocarbon group, a phenyl group, a hydrogen atom, a
hydroxyl group, a cyano group, an amino group, a nitro group and a
nitroso group; and the chained saturated hydrocarbon group, the
chained unsaturated hydrocarbon group, the cyclic saturated
hydrocarbon group and the cyclic unsaturated hydrocarbon group each
contain at least one selected from the group consisting of a carbon
atom, an oxygen atom, a nitrogen atom, a sulfur atom and a silicon
atom; and R10 is a chained unsaturated hydrocarbon group or a
cyclic unsaturated hydrocarbon group each containing a thiophene
structure, and contains at least one selected from the group
consisting of a carbon atom, an oxygen atom, a nitrogen atom, a
sulfur atom and a silicon atom. ##STR00049##
16. The electricity storage material of claim 15, wherein X is a
sulfur atom; R5 and R6 are each a phenyl group or a chained
hydrocarbon group; and R10 has a structure represented by any of
chemical formulas (8) through (12) shown below. ##STR00050##
17. The electricity storage device of claim 1, wherein: at least
one of the positive electrode and the negative electrode comprises
a conductive support and an electricity storage layer provided on
the conductive support that comprises the electricity storage
material.
18. The electricity storage device of claim 17, wherein the
electricity storage layer contains a conductive substance.
19. The electricity storage device of claim 1, wherein the
electrolyte contains a salt of a quaternary ammonium cation and an
anion.
20. The electricity storage device of claim 17, wherein: the
positive electrode includes the conductive support and the
electricity storage layer provided on the conductive support, the
negative electrode contains a negative electrode active substance
capable of occluding and releasing lithium ion, and the electrolyte
contains a salt formed of the lithium ion and an anion and filling
an area between the positive electrode and the negative
electrode.
21. A mobile electronic device, comprising the electricity storage
device defined by claim 20.
22. A vehicle, comprising the electricity storage device defined by
claim 20.
23. The electricity storage device of claim 1, wherein the positive
electrode comprises the electricity storage material.
24. The electricity storage device of claim 1, wherein the negative
electrode comprises the electricity storage material.
Description
RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application
Ser. No. 12/997,516, filed Dec. 10, 2010, which is the U.S.
National Phase under 35 U.S.C. .sctn.371 of International
Application No. PCT/JP2009/003648, filed on Jul. 31, 2009, which in
turn claims the benefit of Japanese Application No. 2008-198502,
filed on Jul. 31, 2008, the disclosures of which are incorporated
by reference herein.
TECHNICAL FIELD
[0002] The present invention relates to an electricity storage
material and an electricity storage device using the same.
BACKGROUND ART
[0003] Recently, mobile electronic devices such as mobile audio
devices, mobile phones, laptop computers and the like have been
widely used, and various types of secondary batteries have been
used as power supplies for such mobile electronic devices. Also, a
demand for secondary batteries having a much larger capacity than
is provided for the mobile electronic devices has been increased.
For example, from the viewpoint of energy savings or reduction of
carbon dioxide emission, hybrid vehicles using an electric driving
power in addition to the conventional engine are becoming popular.
For these reasons, secondary batteries having further improved
characteristics of output, capacity, cycle life and the like are
now desired regardless of the usage.
[0004] A secondary battery accumulates charges using an
oxidation/reduction reaction. Therefore, a substance which is
reversibly oxidation/reduction-reactable, namely, an electricity
storage material which accumulates charges, greatly influences the
above-described characteristics of the secondary battery.
Conventional secondary batteries use metals, carbon, inorganic
compounds and the like as the electricity storage materials. In the
case of, for example, lithium secondary batteries widely used
today, metal oxides, graphite and the like are used as positive
electrode active substances and negative electrode active
substances which are electricity storage materials.
[0005] In place of these inorganic materials, it is now being
studied to use organic compounds as the electricity storage
materials. Organic compounds allow more diversified molecule
designs than inorganic compounds. It is considered that when an
organic compound is used as an active substance, such an active
substance can have various characteristics by molecule design.
[0006] Organic compounds are more lightweight than metals.
Therefore, when a secondary battery is formed using an electricity
storage material formed of an organic compound, the obtained
secondary battery can be lightweight. For this reason, organic
compounds are considered to be preferable for secondary batteries
for hybrid vehicles, which do not need to have a high charging
density but need to be lightweight. It has also been studied to use
capacitors as electricity storage devices for hybrid vehicles. The
above-described advantages of organic compounds are also provided
when electricity storage materials formed of organic compounds are
used for capacitors using a chemical reaction.
[0007] In Patent Documents Nos. 1 and 2, the present inventors have
proposed an organic compound having a .pi.-conjugated electron
cloud as a novel electricity storage material which can provide
high speed charge/discharge, and clarified a reaction mechanism
thereof.
CITATION LIST
Patent Literature
[0008] Patent Document No. 1: Japanese Laid-Open Patent Publication
No. 2004-111374
[0009] Patent Document No. 2: Japanese Laid-Open Patent Publication
No. 2004-342605
SUMMARY OF INVENTION
Technical Problem
[0010] For an electrolytic solution of an electricity storage
device, a non-aqueous solvent is used in order to broaden the
usable voltage range. Therefore, when an organic compound is used
as the electricity storage material, a problem arises that the
electricity storage material may occasionally elute into the
electrolytic solution. Even if the solubility of the electricity
storage material in the electrolytic solution is very low, if the
electricity storage material elutes little by little while the
charge/discharge operation is repeated, a good charge/discharge
cycle characteristic is not obtained.
[0011] The present invention has an object of solving such problems
of the conventional art and providing a novel active substance
containing an organic compound which does not elute into an
electrolytic solution and has excellent characteristics of output,
capacity, cycle life and the like and also an electricity storage
device using the same.
Solution to Problem
[0012] An electricity storage material according to the present
invention contains a polymerization product which has a
tetrachalcogenofulvalene structure in a repeat unit of a main
chain.
[0013] In a preferable embodiment, the main chain of the
polymerization product is formed of the tetrachalcogenofulvalene
structures directly bonded to each other.
[0014] In a preferable embodiment, the polymerization product is a
copolymerization product of two or more types of monomers which
contain the tetrachalcogenofulvalene structures having different
substituents from each other.
[0015] In a preferable embodiment, the polymerization product is a
copolymerization product of a monomer containing at least one of an
acetylene structure and a thiophene structure and a monomer
containing the tetrachalcogenofulvalene structure.
[0016] In a preferable embodiment, the tetrachalcogenofulvalene
structure is a tetrathiafulvalene structure.
[0017] In a preferable embodiment, the polymerization product has a
degree of polymerization of 4 or greater.
[0018] In a preferable embodiment, the tetrachalcogenofulvalene
structure is represented by general formula (1) shown below. In
general formula (1), X is an oxygen atom, a sulfur atom, a selenium
atom or a tellurium atom; two selected from R1 through R4 each
represent a bond with an adjacent repeat unit; and the other two
are each independently at least one selected from the group
consisting of a chained saturated hydrocarbon group, a chained
unsaturated hydrocarbon group, a cyclic saturated hydrocarbon
group, a cyclic unsaturated hydrocarbon group, a phenyl group, a
hydrogen atom, a hydroxyl group, a cyano group, an amino group, a
nitro group and a nitroso group. The chained saturated hydrocarbon
group, the chained unsaturated hydrocarbon group, the cyclic
saturated hydrocarbon group and the cyclic unsaturated hydrocarbon
group each contain at least one selected from the group consisting
of a carbon atom, an oxygen atom, a nitrogen atom, a sulfur atom
and a silicon atom.
##STR00001##
[0019] In a preferable embodiment, the polymerization product is
represented by general formula (2) shown below. In general formula
(2), X is an oxygen atom, a sulfur atom, a selenium atom or a
tellurium atom; and R5 and R6 are each independently at least one
selected from the group consisting of a chained saturated
hydrocarbon group, a chained unsaturated hydrocarbon group, a
cyclic saturated hydrocarbon group, a cyclic unsaturated
hydrocarbon group, a phenyl group, a hydrogen atom, a hydroxyl
group, a cyano group, an amino group, a nitro group and a nitroso
group. The chained saturated hydrocarbon group, the chained
unsaturated hydrocarbon group, the cyclic saturated hydrocarbon
group and the cyclic unsaturated hydrocarbon group each contain at
least one selected from the group consisting of a carbon atom, an
oxygen atom, a nitrogen atom, a sulfur atom and a silicon atom.
##STR00002##
[0020] In a preferable embodiment, X is a sulfur atom; and R5 and
R6 are each a chained hydrocarbon group or an aromatic group.
[0021] In a preferable embodiment, X is a sulfur atom; and R5 and
R6 are each C.sub.6H.sub.13, C.sub.10H.sub.21, C.sub.8H.sub.17 or
C.sub.6H.sub.5.
[0022] In a preferable embodiment, the polymerization product is a
copolymerization product containing repeat units represented by
general formulas (3) and (4) shown below. In general formulas (3)
and (4), X is an oxygen atom, a sulfur atom, a selenium atom or a
tellurium atom; and R5 through R8 are each independently at least
one selected from the group consisting of a chained saturated
hydrocarbon group, a chained unsaturated hydrocarbon group, a
cyclic saturated hydrocarbon group, a cyclic unsaturated
hydrocarbon group, a phenyl group, a hydrogen atom, a hydroxyl
group, a cyano group, an amino group, a nitro group and a nitroso
group. The chained saturated hydrocarbon group, the chained
unsaturated hydrocarbon group, the cyclic saturated hydrocarbon
group and the cyclic unsaturated hydrocarbon group each contain at
least one selected from the group consisting of a carbon atom, an
oxygen atom, a nitrogen atom, a sulfur atom and a silicon atom. It
should be noted that a combination of R5 and R6 is different from a
combination of R7 and R8.
##STR00003##
[0023] In a preferable embodiment, X is a sulfur atom; R5 and R6
are each a phenyl group; and R7 and R8 are each a chained
hydrocarbon group.
[0024] In a preferable embodiment, the polymerization product is
represented by general formula (5) shown below. In general formula
(5), X is an oxygen atom, a sulfur atom, a selenium atom or a
tellurium atom; and R5 and R6 are each independently at least one
selected from the group consisting of a chained saturated
hydrocarbon group, a chained unsaturated hydrocarbon group, a
cyclic saturated hydrocarbon group, a cyclic unsaturated
hydrocarbon group, a phenyl group, a hydrogen atom, a hydroxyl
group, a cyano group, an amino group, a nitro group and a nitroso
group. The chained saturated hydrocarbon group, the chained
unsaturated hydrocarbon group, the cyclic saturated hydrocarbon
group and the cyclic unsaturated hydrocarbon group each contain at
least one selected from the group consisting of a carbon atom, an
oxygen atom, a nitrogen atom, a sulfur atom and a silicon atom. R9
is a chained unsaturated hydrocarbon group or a cyclic unsaturated
hydrocarbon group each containing an acetylene structure, and
contains at least one selected from the group consisting of a
carbon atom, an oxygen atom, a nitrogen atom, a sulfur atom and a
silicon atom.
##STR00004##
[0025] In a preferable embodiment, X is a sulfur atom; R5 and R6
are each a phenyl group or a chained hydrocarbon group; and R9 has
a structure represented by chemical formula (6) shown below.
##STR00005##
[0026] In a preferable embodiment, the polymerization product is
represented by general formula (7) shown below. In general formula
(7), X is an oxygen atom, a sulfur atom, a selenium atom or a
tellurium atom; and R5 and R6 are each independently at least one
selected from the group consisting of a chained saturated
hydrocarbon group, a chained unsaturated hydrocarbon group, a
cyclic saturated hydrocarbon group, a cyclic unsaturated
hydrocarbon group, a phenyl group, a hydrogen atom, a hydroxyl
group, a cyano group, an amino group, a nitro group and a nitroso
group. The chained saturated hydrocarbon group, the chained
unsaturated hydrocarbon group, the cyclic saturated hydrocarbon
group and the cyclic unsaturated hydrocarbon group each contain at
least one selected from the group consisting of a carbon atom, an
oxygen atom, a nitrogen atom, a sulfur atom and a silicon atom. R10
is a chained unsaturated hydrocarbon group or a cyclic unsaturated
hydrocarbon group each containing a thiophene structure, and
contains at least one selected from the group consisting of a
carbon atom, an oxygen atom, a nitrogen atom, a sulfur atom and a
silicon atom.
##STR00006##
[0027] In a preferable embodiment, X is a sulfur atom; R5 and R6
are each a phenyl group or a chained hydrocarbon group; and R10 has
a structure represented by any of chemical formulas (8) through
(12) shown below.
##STR00007##
[0028] In a preferable embodiment, the polymerization product is
represented by general formula (13) shown below. In general formula
(13), X is an oxygen atom, a sulfur atom, a selenium atom or a
tellurium atom; and R5 through R8 are each independently at least
one selected from the group consisting of a chained saturated
hydrocarbon group, a chained unsaturated hydrocarbon group, a
cyclic saturated hydrocarbon group, a cyclic unsaturated
hydrocarbon group, a phenyl group, a hydrogen atom, a hydroxyl
group, a cyano group, an amino group, a nitro group and a nitroso
group. The chained saturated hydrocarbon group, the chained
unsaturated hydrocarbon group, the cyclic saturated hydrocarbon
group and the cyclic unsaturated hydrocarbon group each contain at
least one selected from the group consisting of a carbon atom, an
oxygen atom, a nitrogen atom, a sulfur atom and a silicon atom. R11
and R12 are each independently a chained unsaturated hydrocarbon
group or a cyclic unsaturated hydrocarbon group each containing
either an acetylene structure or a thiophene structure, and
contains at least one selected from the group consisting of a
carbon atom, an oxygen atom, a nitrogen atom, a sulfur atom and a
silicon atom.
##STR00008##
[0029] In a preferable embodiment, X is a sulfur atom; R5 through
R8 are each a phenyl group, a chained hydrocarbon group or a
thioalkyl group; and R11 and R12 each have a structure represented
by chemical formula (14) shown below.
##STR00009##
[0030] In a preferable embodiment, the polymerization product is
represented by general formula (15) shown below. In general formula
(15), Ph is a bivalent aromatic hydrocarbon group; X is an oxygen
atom, a sulfur atom, a selenium atom or a tellurium atom; and R5
and R6 each independently contain at least one selected from the
group consisting of a chained saturated hydrocarbon group, a
chained unsaturated hydrocarbon group, a cyclic saturated
hydrocarbon group, a cyclic unsaturated hydrocarbon group, a phenyl
group, a hydrogen atom, a hydroxyl group, a cyano group, an amino
group, a nitro group and a nitroso group. The chained saturated
hydrocarbon group, the chained unsaturated hydrocarbon group, the
cyclic saturated hydrocarbon group and the cyclic unsaturated
hydrocarbon group each contain at least one selected from the group
consisting of a carbon atom, an oxygen atom, a nitrogen atom, a
sulfur atom and a silicon atom.
##STR00010##
[0031] In a preferable embodiment, the polymerization product is
represented by general formula (16) shown below. In general formula
(16), X is an oxygen atom, a sulfur atom, a selenium atom or a
tellurium atom; and R5, R6 and R13 through R16 each independently
contain at least one selected from the group consisting of a
chained saturated hydrocarbon group, a chained unsaturated
hydrocarbon group, a cyclic saturated hydrocarbon group, a cyclic
unsaturated hydrocarbon group, a phenyl group, a hydrogen atom, a
hydroxyl group, a cyano group, an amino group, a nitro group and a
nitroso group. The chained saturated hydrocarbon group, the chained
unsaturated hydrocarbon group, the cyclic saturated hydrocarbon
group and the cyclic unsaturated hydrocarbon group each contain at
least one selected from the group consisting of a carbon atom, an
oxygen atom, a nitrogen atom, a sulfur atom and a silicon atom.
##STR00011##
[0032] In a preferable embodiment, the polymerization product is
represented by general formula (17) shown below. In general formula
(17), X is an oxygen atom, a sulfur atom, a selenium atom or a
tellurium atom; and R5, R6 and R13 through R16 each independently
contain at least one selected from the group consisting of a
chained saturated hydrocarbon group, a chained unsaturated
hydrocarbon group, a cyclic saturated hydrocarbon group, a cyclic
unsaturated hydrocarbon group, a phenyl group, a hydrogen atom, a
hydroxyl group, a cyano group, an amino group, a nitro group and a
nitroso group. The chained saturated hydrocarbon group, the chained
unsaturated hydrocarbon group, the cyclic saturated hydrocarbon
group and the cyclic unsaturated hydrocarbon group each contain at
least one selected from the group consisting of a carbon atom, an
oxygen atom, a nitrogen atom, a sulfur atom and a silicon atom.
##STR00012##
[0033] In a preferable embodiment, X is a sulfur atom; R5 and R6
are each a thioalkyl group; and R13 through R16 are each a hydrogen
atom.
[0034] An electrode according to the present invention comprises a
conductive support; and an electricity storage layer provided on
the conductive support and containing an electricity storage
material defined by any one of the above.
[0035] In a preferable embodiment, the electricity storage layer
contains a conductive substance.
[0036] An electrochemical element according to the present
invention comprises a positive electrode, a negative electrode, and
an electrolytic solution located between the positive electrode and
the negative electrode. At least one of the positive electrode and
the negative electrode has the above-described electrode.
[0037] In a preferable embodiment, the electrolytic solution
contains a salt of a quaternary ammonium cation and an anion.
[0038] An electricity storage device according to the present
invention comprises a positive electrode, a negative electrode, and
an electrolytic solution located between the positive electrode and
the negative electrode. At least one of the positive electrode and
the negative electrode has the above-described electrode.
[0039] An electricity storage device according to the present
invention comprises a positive electrode having the electrode
defined by any one of the above; a negative electrode containing a
negative electrode active substance capable of occluding and
releasing lithium ion; and an electrolytic solution containing a
salt formed of the lithium ion and an anion and filling an area
between the positive electrode and the negative electrode.
[0040] A mobile electronic device according to the present
invention comprises the above-described electricity storage.
[0041] A vehicle according to the present invention comprises the
above-described electricity storage device.
Advantageous Effects of Invention
[0042] An electricity storage material according to the present
invention contains a polymerization product having a
tetrachalcogenofulvalene structure in a repeat unit of a main
chain. Since the tetrachalcogenofulvalene structure which is
reversibly oxidation/reduction-reactable is polymerized, the
molecular weight of a molecule containing the
tetrachalcogenofulvalene structure is increased, and thus the
solubility thereof in an organic solvent is decreased. For this
reason, an electricity storage material according to the present
invention is difficult to be dissolved in an organic solvent, and
so can be suppressed from eluting into an electrolytic solution
even when being used in an electricity storage device. Therefore,
an electricity storage device having a long cycle life is
realized.
[0043] Since the tetrachalcogenofulvalene structure is contained in
the main chain of the polymerization product, the site which is
subjected to an oxidation/reduction reaction contributes to the
polymerization of the polymerization product without the reversible
oxidation/reduction reactability of tetrachalcogenofulvalene being
spoiled. Therefore, a structure of the polymerization product, in
which a portion that is not subjected to the oxidation/reduction
reaction is as small as possible, can be formed. Owing to this, an
electricity storage material having a high energy density and an
excellent charge/discharge or oxidation/reduction cycle
characteristic can be realized. In addition, an electricity storage
device having a large output, a large capacity and an excellent
cycle characteristic can be provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0044] FIG. 1 is a schematic cross-sectional view showing a
coin-type secondary battery as one embodiment of an electricity
storage device according to the present invention.
[0045] FIG. 2 is a cross-sectional view showing a structure of a
positive electrode of the secondary battery in FIG. 1.
[0046] FIG. 3 shows a charge/discharge curve of electricity storage
device A in an example.
[0047] FIG. 4 shows a charge/discharge curve of electricity storage
device B in an example.
[0048] FIG. 5 shows a charge/discharge curve of electricity storage
device C in an example.
[0049] FIG. 6 shows a charge/discharge curve of electricity storage
device D in an example.
[0050] FIG. 7 shows a charge/discharge curve of electricity storage
device E in an example.
[0051] FIG. 8 shows a charge/discharge curve of electricity storage
device F in an example.
[0052] FIG. 9 shows a charge/discharge curve of electricity storage
device G in an example.
DESCRIPTION OF EMBODIMENTS
[0053] Hereinafter, an embodiment of an electricity storage
material and an electricity storage device according to the present
invention will be described with reference to the drawings. In this
embodiment, an electricity storage material and an electricity
storage device according to the present invention will be described
by way of an example of a lithium secondary battery. However, the
present invention is not limited to a lithium secondary battery or
a positive electrode active substance of the lithium secondary
battery, and is preferably applicable to a capacitor using a
chemical reaction or the like.
[0054] FIG. 1 is a cross-sectional view schematically showing a
lithium secondary battery as an embodiment of an electricity
storage device according to the present invention. The secondary
battery shown in FIG. 1 includes a positive electrode 31, a
negative electrode 32 and a separator 24. The positive electrode 31
includes a positive electrode active substance layer 23 and a
positive electrode current collector 22, and the positive electrode
active substance layer 23 is supported by the positive electrode
current collector 22. Similarly, the negative electrode 32 includes
a negative electrode active substance layer 26 and a negative
electrode current collector 27, and the negative electrode active
substance layer 26 is supported by the negative electrode current
collector 27.
[0055] As described below in detail, the positive electrode active
substance layer 23 contains an electricity storage material
according to the present invention as a positive electrode active
substance. Usable as the positive electrode current collector 22
is, for example, a metal foil or a metal mesh formed of aluminum,
gold, silver, stainless steel, an aluminum alloy or the like, or a
resin film containing a conductive filler formed of such a
metal.
[0056] The negative electrode active substance layer 26 contains a
negative electrode active substance. The negative electrode active
substance used here is a known negative electrode active substance
for reversibly occluding and releasing lithium. Examples of
substances usable as the negative electrode active substance
include materials capable of reversibly occluding and releasing
lithium such as graphite materials, e.g., natural graphite,
artificial graphite, etc., non-amorphous carbon materials, lithium
metal, lithium-containing composite nitrides, lithium-containing
titanium oxides, silicon, alloys containing silicon, silicon
oxides, tin, alloys containing tin, tin oxides, and the like;
carbon materials having an electric double layer capacity such as
activated carbon, etc.; organic compound materials having a
.pi.-conjugated electron cloud; and the like. Such negative
electrode materials may be used independently or as a mixture of a
plurality thereof. Usable for the negative electrode current
collector 27 is a material which is known as being usable for a
current collector of a negative electrode of a lithium ion
secondary battery, for example, copper, nickel, stainless steel, or
the like. Similarly to the positive electrode current collector 22,
the negative electrode current collector 27 is usable in the form
of a metal foil, a metal mesh or a resin film containing a
conductive filler formed of a metal.
[0057] The positive electrode active substance layer 23 and the
negative electrode active substance layer 26 may respectively
contain only a positive electrode active substance and only a
negative electrode active substance, or may each contain either one
of a conductor or a binder, or both of a conductor and a binder. As
the conductor, any of various electron conductive materials which
are not chemically changed at a charge/discharge potential of the
positive electrode active substance or the negative electrode
active substance is usable. Examples of substances usable as the
conductor include carbon materials such as carbon black, graphite,
acetylene black and the like; conductive polymerization products
such as polyaniline, polypyrrole, polythiophene and the like;
conductive fibers such as carbon fiber, metal fiber and the like;
metal powders; conductive whiskers; conductive metal oxides; and
the like. These materials may be used independently or as a mixture
thereof. An ion-conductive assisting agent may be contained in the
positive electrode. Usable as the ion-conductive assisting agent
is, for example, a solid electrolyte formed of polyethylene oxide
or the like, or a gel electrolyte formed of poly(methyl
methacrylate) or the like.
[0058] The binder may be either a thermoplastic resin or a
thermosetting resin. Examples of substances usable as the binder
include polyolefin resins such as polyethylene, polypropylene and
the like; fluorine-based resins such as polytetrafluoroethylene
(PTFE), poly(vinylidene fluoride) (PVDF), hexafluoropropylene (HFP)
and the like, and copolymeric resins thereof; styrene-butadiene
rubber; polyacrylic resin and copolymeric resins thereof; and the
like.
[0059] The positive electrode 31 and the negative electrode 32 are
located such that the positive electrode active substance layer 23
and the negative electrode active substance layer 26 face each
other while sandwiching, and being in contact with, the separator
24. Thus, these elements form an electrode group. The separator 24
is a resin layer formed of a resin which does not have electron
conductivity, and is a porous film having a high level of ion
permeability and prescribed levels of mechanical strength and
electric insulation. For the separator 24, a polyolefin resin
containing polypropylene, polyethylene or the like independently or
as a mixture thereof is preferable because these materials have a
high organic solvent resistance and a high hydrophobicity. The
separator 24 may be replaced with an ion-conductive resin layer
which is swollen with an electrolytic solution and acts as a gel
electrolyte.
[0060] The electrode group is accommodated in a space inside a case
21. Into the space inside the case 21, an electrolytic solution 29
is injected. The positive electrode 31, the negative electrode 32
and the separator 24 are impregnated with the electrolytic solution
29. The separator 24 contains tiny spaces for holding the
electrolytic solution 29. Therefore, the electrolytic solution 29
is held in the tiny spaces, and thus is located between the
positive electrode 31 and the negative electrode 32. An opening of
the case 21 is sealed by a sealing plate 25 using a gasket 28.
[0061] The electrolytic solution 29 is formed of a non-aqueous
solvent and a support salt soluble in the non-aqueous solvent.
Usable as the non-aqueous solvent is a known solvent usable for a
non-aqueous secondary battery or a non-aqueous electric double
layer capacitor. Specifically, a solvent containing a cyclic
carbonate ester is preferably usable because a cyclic carbonate
ester has a very high relative dielectric constant as exhibited by
ethylene carbonate and propylene carbonate. Among cyclic carbonate
esters, propylene carbonate is preferable because propylene
carbonate has a freezing point of -49.degree. C., which is lower
than that of ethylene carbonate and thus can cause the electricity
storage device to operate even at a low temperature.
[0062] A solvent containing a cyclic ester is also preferably
usable for the following reason. A cyclic ester has a very high
relative dielectric constant as exhibited by .gamma.-butyrolactone.
Therefore, the electrolytic solution 29 containing a non-aqueous
solvent which contains a cyclic ester can have a very high relative
dielectric constant as a whole.
[0063] As the non-aqueous solvent, one of the above-described
substances may be used or a mixture of a plurality thereof may be
used. Examples of substances usable as the non-aqueous solvent
include chained carbonate esters, chained esters, cyclic or chained
ethers and the like. Specific examples of the substances usable as
the non-aqueous solvent include dimethyl carbonate, diethyl
carbonate, methylethyl carbonate, tetrahydrofran, dioxolane,
sulfolane, dimethyl formamide, acetonitrile, dimethyl sulfoxide,
and the like. Preferably, the relative dielectric constant of the
non-aqueous solvent is 55 or greater and 90 or less.
[0064] As the support salt, a salt formed of any of the following
anions and any of the following cations is usable. Usable anions
include halide anion, perchloric acid anion,
trifluoromethanesulfonic acid anion, tetrafluoroboric acid anion,
hexafluorophosphoric acid anion, nonafluoro-1-butanesulfonic acid
anion, bis(trifluoromethanesulfonyl)imide anion,
bis(perfluoroethylsulfonyl)imide anion, and the like. Usable
cations include alkaline metal cations of lithium, sodium,
potassium and the like; alkaline earth metal cations of magnesium
and the like; quaternary ammonium cations of tetraethylammonium,
1-ethyl-3-methyl-imidazolium and the like.
[0065] As the cation, a quaternary ammonium cation or a lithium
cation is preferable. A quaternary ammonium cation has a high level
of ion mobility and so provides a highly conductive electrolytic
solution, and also allows use of a negative electrode having an
electric double layer capacity such as activated carbon or the
like, which has a high reaction rate, as a counter electrode. For
these reasons, use of a quaternary ammonium cation realizes a
large-output electricity storage device. A lithium cation allows
use of a negative electrode, which has a low reaction potential and
a large capacity density and is capable of occluding and releasing
lithium, as a counter electrode. For these reasons, use of a
lithium cation realizes a high voltage, high energy density
electricity storage device.
[0066] FIG. 2 is an enlarged cross-sectional view schematically
showing a structure of the positive electrode 31. The positive
electrode active substance layer 23 supported by the positive
electrode current collector 22 contains positive electrode active
substance particles 41 and a conductive agent portion 42 formed of
a conductor and a binder. The conductive agent portion 42 is porous
so as to hold the electrolytic solution 29. In FIG. 2, the positive
electrode active substance particles 41 are schematically shown as
being circular, but each positive electrode active substance
particle 41 has a shape of a chained polymerization product folded
and aggregated. By the chained polymerization product being folded,
hollow holes are formed and thus the electrolytic solution 29 can
enter the inside of the particle. The positive electrode active
substance particle 41 has a generally spherical shape, but there is
no specific limitation on the shape of the positive electrode
active substance particle 41 as long as the shape is formed by the
chained polymerization products being aggregated. The size of the
positive electrode active substance particle 41 is about 1 .mu.m to
10 .mu.m.
[0067] Hereinafter, an electricity storage material used as the
positive electrode active substance particles 41 will be described
in detail. An electricity storage material according to the present
invention is an organic compound which is reversibly
oxidation/reduction-reactable, and specifically is a polymerization
product having a tetrachalcogenofulvalene structure in a repeat
unit of a main chain. The tetrachalcogenofulvalene structure is
represented by the following general formula (1).
##STR00013##
[0068] In the formula, X is chalcogen, namely, a group XVI element
in the periodic table. Specifically, chalcogen is an oxygen atom, a
sulfur atom, a selenium atom or a tellurium atom. Two selected from
R1 through R4 each represent a bond with an adjacent
tetrachalcogenofulvalene structure represented by general formula
(1) or a bond with a monomer having a chemical structure other than
the structure represented by general formula (1). The other two of
R1 through R4 are each independently at least one selected from the
group consisting of a chained saturated hydrocarbon group, a
chained unsaturated hydrocarbon group, a cyclic saturated
hydrocarbon group, a cyclic unsaturated hydrocarbon group, a phenyl
group, a hydrogen atom, a hydroxyl group, a cyano group, an amino
group, a nitro group and a nitroso group. The chained saturated
hydrocarbon group, the chained unsaturated hydrocarbon group, the
cyclic saturated hydrocarbon group and the cyclic unsaturated
hydrocarbon group each contain at least one selected from the group
consisting of a carbon atom, an oxygen atom, a nitrogen atom, a
sulfur atom and a silicon atom.
[0069] The tetrachalcogenofulvalene structure represented by
general formula (1) contains, in each of the two five-member rings,
a chalcogen atom having an unpaired electron and a double bond.
Owing to this, a n-conjugated electron cloud in which the
five-member rings are delocalized is formed. Therefore, the
tetrachalcogenofulvalene structure can be kept stable even in an
oxidized state caused by one .pi. electron being released from each
of the two five-member rings.
[0070] As represented by the following formula (R1), when the
tetrachalcogenofulvalene structure represented by general formula
(1) is subjected to one-electron oxidation, an electron is pulled
out from one of the two five-member rings and so this five-member
ring is charged positive. Therefore, one counter anion coordinates
to the tetrachalcogenofulvalene structure. When the
tetrachalcogenofulvalene structure is further subjected to
one-electron oxidation, an electron is pulled out from the other
five-member ring and so this five-member ring is charged positive.
Therefore, one more counter anion coordinates to the
tetrachalcogenofulvalene structure.
[0071] The tetrachalcogenofulvalene structure is stable even in an
oxidized state, and can be reduced by receiving an electron and
return to an electrically neutral state. Accordingly, by using such
a reversible oxidation/reduction reaction, the
tetrachalcogenofulvalene structure can be used for an electricity
storage material in which charges can be stored. For example, where
the tetrachalcogenofulvalene structure represented by general
formula (1) is used for a positive electrode of a lithium secondary
battery, the tetrachalcogenofulvalene structure is in an
electrically neutral state, i.e., in the state shown left in
formula (R1), when being discharged. In a charged state, the
tetrachalcogenofulvalene structure is in a positively charged
state, i.e., in the state shown right in formula (R1).
##STR00014##
[0072] An electricity storage material according to the present
invention contains the tetrachalcogenofulvalene structure
represented by general formula (1) in a repeat unit of the main
chain of the polymerization product. As a result of the
tetrachalcogenofulvalene structure represented by general formula
(1) being progressively polymerized, the molecular weight of a
molecule containing the tetrachalcogenofulvalene structure
increases, and thus the solubility thereof in an organic solvent
decreases. Therefore, the deterioration of the cycle characteristic
of an electricity storage device which uses an organic solvent for
an electrolytic solution can be suppressed. Especially by the
tetrachalcogenofulvalene structure being contained in the main
chain of the polymerization product, the site which is subjected to
an oxidation/reduction reaction contributes to the polymerization
of the polymerization product. Therefore, a structure of the
polymerization product, in which the portion that is not subjected
to the oxidation/reduction reaction is as small as possible, can be
formed. Owing to this, an electricity storage material having a
high energy density and an excellent charge/discharge or
oxidation/reduction cycle characteristic can be realized.
[0073] As polymerization products having a .pi.-conjugated electron
cloud, polyaniline, polythiophene and derivatives thereof are
known. These polymerization products are very similar to the
polymerization product of an electricity storage material according
to the present invention on the point of containing a
.pi.-conjugated electron cloud in the main chain. However, in
polyaniline, polythiophene and derivatives thereof, a resonance
structure by a conjugated double bond is formed in the entirety of
the main chain. Therefore, when an electron is pulled out from the
main chain, the positive charge generated by this is distributed in
an area expanded to a certain degree in the main chain. As a
result, when it is attempted to pull out another electron
successively from an adjacent repeat unit, the positive charge
generated by the first electron being pulled out is delocalized
over the adjacent repeat unit, which makes it difficult to pull the
electron from the adjacent unit due to an electric repulsion.
[0074] By contrast, in the case of the polymerization product
having the tetrachalcogenofulvalene structure represented by
general formula (1), electrons are delocalized only in each
five-member ring of the .pi.-conjugated electron cloud. Therefore,
the oxidation/reduction reaction is completed within each
five-member ring of the polymerization product. It is considered
that an oxidized state of one five-member ring does not
significantly influence the oxidation/reduction reaction of a
five-member ring adjacent thereto. For this reason, electrons can
be transferred in correspondence with the number of five-member
rings contained in the polymerization product. Namely, the
electricity storage material according to the present invention can
achieve a large electricity storage capacity.
[0075] As described above, it is preferable that the molecular
weight of the polymerization product having the
tetrachalcogenofulvalene structure represented by general formula
(1) is as large as possible so that the polymerization product is
not dissolved in an organic solvent. Specifically, it is preferable
that the polymerization product contains four or more
tetrachalcogenofulvalene structures represented by general formula
(1); namely, the degree of polymerization of the polymerization
product (n, or a sum of n and m, in the following general formula
or chemical formula) is 4 or greater. Owing to this, an electricity
storage material which is difficult to be dissolved in an organic
solvent is realized. More preferably, the degree of polymerization
of the polymerization product is 10 or greater, and still more
preferably, is 20 or greater.
[0076] The polymerization product having the
tetrachalcogenofulvalene structure may be a copolymerization
product of a monomer having the tetrachalcogenofulvalene structure
represented by general formula (1) and a monomer having a chemical
structure other than the structure represented by general formula
(1), as long as the polymerization product contains the
tetrachalcogenofulvalene structure represented by general formula
(1). It should be noted that in order to provide a higher energy
density, it is preferable that tetrachalcogenofulvalene structures
are directly bonded together to form the main chain of the
polymerization product. In this case, for example, the
polymerization product may be a copolymerization product of two or
more monomers, each of which contains a tetrachalcogenofulvalene
structure represented by general formula (1), but the groups of the
tetrachalcogenofulvalene structure, among R1 through R4, which are
not used for the bond with an adjacent tetrachalcogenofulvalene
structure need to be different among the monomers. In other words,
the polymerization product may be a copolymerization product of two
or more monomers which all contain a tetrachalcogenofulvalene
structure but are different in terms of the substituent.
[0077] Hereinafter, a polymerization product of an electricity
storage material according to the present invention will be
described more specifically.
[0078] First, a polymerization product represented by the following
general formula (2), in which R1 and R3 of the
tetrachalcogenofulvalene structure represented by general formula
(1), i.e., position 1 and position 4 of the
tetrachalcogenofulvalene structure, are bonded with position and
position 1 of adjacent tetrachalcogenofulvalene structures, is
usable for an electricity storage material according to the present
invention. In a polymerization product represented by general
formula (2), the tetrachalcogenofulvalene structures are directly
bonded to each other to form the main chain of the polymerization
product. Therefore, the ratio of portions which contribute to the
oxidation/reduction reaction with respect to the entire main chain
is high, and thus the obtained electricity storage material can
accumulate charges at a high energy density.
##STR00015##
[0079] In general formula (2), X is an oxygen atom, a sulfur atom,
a selenium atom or a tellurium atom. R5 and R6 are each
independently at least one selected from the group consisting of a
chained saturated hydrocarbon group, a chained unsaturated
hydrocarbon group, a cyclic saturated hydrocarbon group, a cyclic
unsaturated hydrocarbon group, a phenyl group, a hydrogen atom, a
hydroxyl group, a cyano group, an amino group, a nitro group and a
nitroso group. The chained saturated hydrocarbon group, the chained
unsaturated hydrocarbon group, the cyclic saturated hydrocarbon
group and the cyclic unsaturated hydrocarbon group each contain at
least one selected from the group consisting of a carbon atom, an
oxygen atom, a nitrogen atom, a sulfur atom and a silicon atom;
namely, may contain an oxygen atom, a nitrogen atom, a sulfur atom
or a silicon atom in addition to the carbon atom. n represents the
degree of polymerization and is an integer of 2 or greater (this is
also applied to the general formulas and the chemical formulas
shown below).
[0080] X is preferably a sulfur atom, and R5 and R6 are preferably
a chained hydrocarbon group or an aromatic group. Where X is a
sulfur atom, as compared with the case where X is a selenium atom
or a tellurium atom, the atomic weight is smaller and so the energy
density per weight is larger. Again, where X is a sulfur atom, as
compared to the case where X is an oxygen atom, the
oxidation/reduction potential is higher and so the discharge
voltage can be higher when such a polymerization product is used as
a positive electrode material. For example, an electricity storage
material according to the present invention is represented by any
of chemical formulas (21) through (24) in which X.dbd.S and R5 and
R6 are each C.sub.6H.sub.13, C.sub.10H.sub.21, C.sub.8H.sub.17 or
C.sub.6H.sub.5.
##STR00016##
[0081] An electricity storage material according to the present
invention may be a copolymerization product containing repeat units
represented by the following general formulas (3) and (4). In both
of the polymerization products represented by general formulas (3)
and (4), positions 1 and of the tetrachalcogenofulvalene structure
are directly bonded to positions 4 and 1 of adjacent
tetrachalcogenofulvalene structures, but the
tetrachalcogenofulvalene structures in the repeat units of these
polymerization products have different substituents. In a
copolymerization product containing the repeat units represented by
general formulas (3) and (4) also, the tetrachalcogenofulvalene
structures are directly bonded to each other to form the main chain
of the copolymerization product. Therefore, the ratio of portions
which contribute to the oxidation/reduction reaction with respect
to the entire main chain is high, and thus the obtained electricity
storage material can accumulate charges at a high energy
density.
##STR00017##
[0082] In general formulas (3) and (4), X is an oxygen atom, a
sulfur atom, a selenium atom or a tellurium atom. R5 through R8 are
each independently at least one selected from the group consisting
of a chained saturated hydrocarbon group, a chained unsaturated
hydrocarbon group, a cyclic saturated hydrocarbon group, a cyclic
unsaturated hydrocarbon group, a phenyl group, a hydrogen atom, a
hydroxyl group, a cyano group, an amino group, a nitro group and a
nitroso group. The chained saturated hydrocarbon group, the chained
unsaturated hydrocarbon group, the cyclic saturated hydrocarbon
group and the cyclic unsaturated hydrocarbon group each contain at
least one selected from the group consisting of a carbon atom, an
oxygen atom, a nitrogen atom, a sulfur atom and a silicon atom. It
should be noted that a combination of R5 and R6 is different from a
combination of R7 and R8.
[0083] For example, R5 and R6 may each be a phenyl group, whereas
R7 and R8 may each be a chained hydrocarbon group. The chained
hydrocarbon group may be a polymerization product represented by
the following chemical formula (25), which is a decyl group. In the
chemical formula, a sum of n and m represents the degree of
polymerization and is an integer of 2 or greater. The two repeat
units each having a tetrachalcogenofulvalene structure may be
arranged regularly or randomly. The ratio of n and m is arbitrary.
It is preferable that the molecular weight of the polymerization
product is as large as possible so that the polymerization product
is not dissolved in an organic solvent. Specifically, it is
preferable that the polymerization product contains four or more
tetrachalcogenofulvalene structures; namely, the degree of
polymerization of the polymerization product (sum of n and m) is 4
or greater.
##STR00018##
[0084] An electricity storage material according to the present
invention may be a polymerization product represented by the
following general formula (5). Such a polymerization product has a
main chain in which chained unsaturated hydrocarbon groups or
cyclic unsaturated hydrocarbon groups each containing an acetylene
structure as a linker are alternately arranged with the
tetrachalcogenofulvalene structures. In a polymerization product
represented by general formula (5), the tetrachalcogenofulvalene
structures form the main chain with the chained unsaturated
hydrocarbon groups or cyclic unsaturated hydrocarbon groups each
containing an acetylene structure being sandwiched between the
tetrachalcogenofulvalene structures. Therefore, the chained
unsaturated hydrocarbon groups or cyclic unsaturated hydrocarbon
groups each containing an acetylene structure suppress an
electronic mutual interaction between the tetrachalcogenofulvalene
structures and thus can improve the stability of each
tetrachalcogenofulvalene structure against the electrochemical
oxidation/reduction reaction. As a result, all the
tetrachalcogenofulvalene structures in the polymerization product
can be reversibly oxidized/reduced, which can realize a large
capacity electricity storage body.
##STR00019##
[0085] In general formula (5), X is an oxygen atom, a sulfur atom,
a selenium atom or a tellurium atom. R5 and R6 are each
independently at least one selected from the group consisting of a
chained saturated hydrocarbon group, a chained unsaturated
hydrocarbon group, a cyclic saturated hydrocarbon group, a cyclic
unsaturated hydrocarbon group, a phenyl group, a hydrogen atom, a
hydroxyl group, a cyano group, an amino group, a nitro group and a
nitroso group. The chained saturated hydrocarbon group, the chained
unsaturated hydrocarbon group, the cyclic saturated hydrocarbon
group and the cyclic unsaturated hydrocarbon group each contain at
least one selected from the group consisting of a carbon atom, an
oxygen atom, a nitrogen atom, a sulfur atom and a silicon atom. R9
is a chained unsaturated hydrocarbon group or a cyclic unsaturated
hydrocarbon group each containing an acetylene structure, and
contains at least one selected from the group consisting of a
carbon atom, an oxygen atom, a nitrogen atom, a sulfur atom and a
silicon atom.
[0086] For example, the electricity storage material may be a
polymerization product represented by the following chemical
formula (26), in which X is a sulfur atom, R5 and R6 are each a
phenyl group, and R9 has a structure represented by the following
chemical formula (6).
##STR00020##
[0087] An electricity storage material according to the present
invention may be a polymerization product represented by the
following general formula (7). Such a polymerization product has a
main chain in which chained unsaturated hydrocarbon groups or
cyclic unsaturated hydrocarbon groups each containing a thiophene
structure as a linker are alternately arranged with the
tetrachalcogenofulvalene structures. In a polymerization product
represented by general formula (7) also, the
tetrachalcogenofulvalene structures form the main chain with the
chained unsaturated hydrocarbon groups or cyclic unsaturated
hydrocarbon groups each containing a thiophene structure being
sandwiched between the tetrachalcogenofulvalene structures.
Therefore, the chained unsaturated hydrocarbon groups or cyclic
unsaturated hydrocarbon groups each containing a thiophene
structure suppress an electronic mutual interaction between the
tetrachalcogenofulvalene structures and thus can improve the
electrochemical stability of each tetrachalcogenofulvalene
structure against the oxidation/reduction reaction. As a result,
all the tetrachalcogenofulvalene structures in the polymerization
product can be reversibly oxidized/reduced, which can realize a
large capacity electricity storage body.
##STR00021##
[0088] In general formula (7), X is an oxygen atom, a sulfur atom,
a selenium atom or a tellurium atom. R5 and R6 are each
independently at least one selected from the group consisting of a
chained saturated hydrocarbon group, a chained unsaturated
hydrocarbon group, a cyclic saturated hydrocarbon group, a cyclic
unsaturated hydrocarbon group, a phenyl group, a hydrogen atom, a
hydroxyl group, a cyano group, an amino group, a nitro group and a
nitroso group. The chained saturated hydrocarbon group, the chained
unsaturated hydrocarbon group, the cyclic saturated hydrocarbon
group and the cyclic unsaturated hydrocarbon group may each contain
at least one selected from the group consisting of a carbon atom,
an oxygen atom, a nitrogen atom, a sulfur atom and a silicon atom.
R10 is a chained unsaturated hydrocarbon group or a cyclic
unsaturated hydrocarbon group each containing a thiophene
structure, and contains at least one selected from the group
consisting of a carbon atom, an oxygen atom, a nitrogen atom, a
sulfur atom and a silicon atom.
[0089] For example, X may be a sulfur atom, R5 and R6 may each be a
phenyl group or a chained hydrocarbon group, and R10 may have a
structure represented by any of the following chemical formulas (8)
through (12).
##STR00022##
[0090] More specifically, an electricity storage material according
to the present invention may be a polymerization product
represented by any of the following chemical formulas (27) through
(32). It is preferable that the polymerization product contains
four or more tetrachalcogenofulvalene structures so that the
polymerization product is not dissolved in an organic solvent.
Namely, it is preferable that n in chemical formulas (27) through
(31) is 4 or greater and that m in chemical formula (32) is 4 or
greater. In a polymerization product represented by chemical
formula (32), the repeat unit having the tetrachalcogenofulvalene
structure and the repeat unit having the thiophene structure may be
arranged regularly or randomly. The ratio of n and m is
arbitrary.
##STR00023##
[0091] An electricity storage material according to the present
invention may be a polymerization product represented by the
following general formula (13). In such a polymerization product,
the main chain has a zigzag structure because the
tetrachalcogenofulvalene structures are alternately polymerized at
a cis position and a trans position.
##STR00024##
[0092] In general formula (13), X is an oxygen atom, a sulfur atom,
a selenium atom or a tellurium atom. R5 through R8 are each
independently at least one selected from the group consisting of a
chained saturated hydrocarbon group, a chained unsaturated
hydrocarbon group, a cyclic saturated hydrocarbon group, a cyclic
unsaturated hydrocarbon group, a phenyl group, a hydrogen atom, a
hydroxyl group, a cyano group, an amino group, a nitro group and a
nitroso group. The chained saturated hydrocarbon group, the chained
unsaturated hydrocarbon group, the cyclic saturated hydrocarbon
group and the cyclic unsaturated hydrocarbon group each contain at
least one selected from the group consisting of a carbon atom, an
oxygen atom, a nitrogen atom, a sulfur atom and a silicon atom.
[0093] R11 and R12 are each independently a chained unsaturated
hydrocarbon group or a cyclic unsaturated hydrocarbon group each
containing at least one of an acetylene structure or a thiophene
structure, and contains at least one selected from the group
consisting of a carbon atom, an oxygen atom, a nitrogen atom, a
sulfur atom and a silicon atom.
[0094] For example, the electricity storage material may be a
polymerization product represented by the following chemical
formula (33), in which X is a sulfur atom, R5 and R6 are each a
thiohexyl group, R7 and R8 are each a phenyl group, and R11 and R12
each have a structure represented by the following chemical formula
(14). It is preferable that the polymerization product contains
four or more tetrachalcogenofulvalene structures so that the
polymerization product is not dissolved in an organic solvent.
Namely, it is preferable that n in chemical formula (33) is 2 or
greater.
##STR00025##
[0095] An electricity storage material according to the present
invention may be a polymerization product represented by the
following general formula (15).
##STR00026##
[0096] In general formula (15), Ph is a bivalent aromatic
hydrocarbon group. X is an oxygen atom, a sulfur atom, a selenium
atom or a tellurium atom. R5 through R8 each independently contain
at least one selected from the group consisting of a chained
saturated hydrocarbon group, a chained unsaturated hydrocarbon
group, a cyclic saturated hydrocarbon group, a cyclic unsaturated
hydrocarbon group, a phenyl group, a hydrogen atom, a hydroxyl
group, a cyano group, an amino group, a nitro group and a nitroso
group. The chained saturated hydrocarbon group, the chained
unsaturated hydrocarbon group, the cyclic saturated hydrocarbon
group and the cyclic unsaturated hydrocarbon group each contain at
least one selected from the group consisting of a carbon atom, an
oxygen atom, a nitrogen atom, a sulfur atom and a silicon atom.
[0097] More specifically, an electricity storage material according
to the present invention may be a polymerization product
represented by the following general formula (16).
##STR00027##
[0098] In general formula (16), X is an oxygen atom, a sulfur atom,
a selenium atom or a tellurium atom. R5, R6, and R13 through R16
each independently contain at least one selected from the group
consisting of a chained saturated hydrocarbon group, a chained
unsaturated hydrocarbon group, a cyclic saturated hydrocarbon
group, a cyclic unsaturated hydrocarbon group, a phenyl group, a
hydrogen atom, a hydroxyl group, a cyano group, an amino group, a
nitro group and a nitroso group. The chained saturated hydrocarbon
group, the chained unsaturated hydrocarbon group, the cyclic
saturated hydrocarbon group and the cyclic unsaturated hydrocarbon
group each contain at least one selected from the group consisting
of a carbon atom, an oxygen atom, a nitrogen atom, a sulfur atom
and a silicon atom.
[0099] For example, the electricity storage material may be a
polymerization product represented by the following chemical
formula (34), in which X is a sulfur atom, R5 and R6 are each a
thioalkyl group, and R13 through R16 are each a hydrogen atom.
##STR00028##
[0100] Alternatively, an electricity storage material according to
the present invention may be a polymerization product represented
by the following general formula (17).
##STR00029##
[0101] In general formula (17), X is an oxygen atom, a sulfur atom,
a selenium atom or a tellurium atom. R5, R6, and R13 through R16
each independently contain at least one selected from the group
consisting of a chained saturated hydrocarbon group, a chained
unsaturated hydrocarbon group, a cyclic saturated hydrocarbon
group, a cyclic unsaturated hydrocarbon group, a phenyl group, a
hydrogen atom, a hydroxyl group, a cyano group, an amino group, a
nitro group and a nitroso group. The chained saturated hydrocarbon
group, the chained unsaturated hydrocarbon group, the cyclic
saturated hydrocarbon group and the cyclic unsaturated hydrocarbon
group each contain at least one selected from the group consisting
of a carbon atom, an oxygen atom, a nitrogen atom, a sulfur atom
and a silicon atom.
[0102] In a polymerization product represented by each of general
formulas (15) through (17) also, the tetrachalcogenofulvalene
structures form the main chain with the chained unsaturated
hydrocarbon groups containing an acetylene structure or a benzene
structure being sandwiched between the tetrachalcogenofulvalene
structures. Therefore, the chained unsaturated hydrocarbon groups
suppress an electronic mutual interaction between the
tetrachalcogenofulvalene structures and thus can improve the
electrochemical stability of each tetrachalcogenofulvalene
structure against the oxidation/reduction reaction. As a result,
all the tetrachalcogenofulvalene structures in the polymerization
product can be reversibly oxidized/reduced, which can realize a
large capacity electricity storage body.
[0103] Each of the above-described polymerization products usable
for an electricity storage material according to the present
invention can be synthesized by polymerizing monomers containing a
repeat unit represented by general formula (1). The synthesis can
be done by any method as long as the polymerization product has the
structure represented by any of general formula (2) through (17)
shown above. However, in order to prevent the dislocation of active
bonding hands in the polymerization product and form a
polymerization product having a high level of regularity, it is
preferable that the polymerization product is synthesized by
polymerization by a coupling reaction. Specifically, the
polymerization product is preferably synthesized as follows.
Monomers are prepared, each of which contains a
tetrachalcogenofulvalene structure having the molecular structure
containing a prescribed substituent as represented by any of
general formulas (2) through (17) shown above and has halogen or
any other functional group at a position acting as a bonding hand
at the time of polymerization. Such monomers are polymerized by a
Sonogashira coupling reaction or any other coupling reaction.
[0104] More specifically, the compounds represented by chemical
formulas (21) through (34) listed above as examples of a
polymerization product usable for an electricity storage material
according to the present invention can each be synthesized by any
of the following four methods. Hereinafter, the compounds
represented by chemical formulas (21) through (34) will
respectively be referred to as "compound 21 through compound
34".
[0105] Compounds 21 through 25 are polymerization products in which
the tetrachalcogenofulvalene structures are directly bonded to each
other. As represented by the following reaction formula (R2), these
compounds can be synthesized by a dehalogenation polycondensation
method using diiodide of tetrachalcogenofulvalene and Ni(O)
complex. In the reaction formula, X represents a sulfur or oxygen
atom, cod represents 1,5-cyclooctadiene, and bpy represents
2,2'-bipyridine.
##STR00030##
[0106] Compounds 27 through 30 and 32 are polymerization products
in which tetrachalcogenofulvalene structures are bonded to each
other with at least a thiophene structure sandwiched therebetween.
As represented by the following reaction formula (R3), these
compounds can be synthesized by a still coupling reaction from
trimethylstannyl of tetrachalcogenofulvalene and iodide of a
thiophene structure using a Pd catalyst. Alternatively, these
compounds can be synthesized by a still coupling reaction from
iodide of tetrachalcogenofulvalene and trimethylstannyl of a
thiophene structure in a similar manner. A polymerization product
obtained by this reaction has a hydrogen atom or a halogen element
derived from a compound used as a starting material, at both ends
thereof.
##STR00031##
[0107] Compounds 31 and 34 are polymerization products in which
tetrachalcogenofulvalene structures are bonded to each other with
triple bond/aromatic/triple bond sandwiched therebetween. As
represented by the following reaction formula (R4), these compounds
can be synthesized by a Sonogashira reaction of diiodide of
tetrachalcogenofulvalene and a compound having a triple bond
position. As understood from reaction formula R4, any compound
having a triple bond position with no specific limitation can bond
the tetrachalcogenofulvalene structures to each other. Although the
linker site contains a thiophene structure in reaction formula R4,
the linker site only needs to be aromatic. For example, the linker
site may contain a benzene ring. Even in this case, a
polymerization product in which the tetrachalcogenofulvalene
structures are bonded to each other with triple
bond/aromatic/triple bond sandwiched therebetween can be
synthesized by substantially the same reaction. A polymerization
product obtained by this reaction has a hydrogen atom or a halogen
element derived from a compound used as a starting material, at
both ends thereof.
##STR00032##
[0108] Compounds 26 and 33 are polymerization products in which
tetrachalcogenofulvalene structures are bonded to each other with
only a triple bond sandwiched therebetween. As represented by the
following reaction formula (R5), these compounds can be synthesized
by a Sonogashira reaction of diiodide of tetrachalcogenofulvalene
and a compound having a triple bond position. A polymerization
product obtained by this reaction has a hydrogen atom or a halogen
element derived from a compound used as a starting material, at
both ends thereof.
##STR00033##
[0109] The above-described synthesis methods of compounds 21, 26,
31 and 32 are described in, for example, J. mater. chem., 1967,
7(10), 1997. The above-described synthesis methods of compounds 22,
23 and 24 are described in, for example, Mol. Cryst. Liq., Vol.
381, 101-112, 2002.
[0110] The synthesis methods of compounds 23, 25, 27 through 30 and
34 will be described in detail in the examples below.
[0111] As described above, an electricity storage device according
to the present invention contains an electricity storage material
which has a tetrachalcogenofulvalene structure in a repeat unit of
a main chain. Therefore, the electricity storage material is formed
of an organic compound, but has a large molecular weight and is low
in the solubility in an organic solvent. Owing to this, the
electricity storage material can suppress the deterioration of the
cycle characteristic of an electricity storage device which uses an
organic solvent for the electrolytic solution. Since the
tetrachalcogenofulvalene structure is contained in the main chain
of the polymerization product, the site which is subjected to an
oxidation/reduction reaction contributes to the polymerization of
the polymerization product. Therefore, a structure of the
polymerization product, in which a portion that is not subjected to
the oxidation/reduction reaction is as small as possible, can be
formed. Owing to this, an electricity storage material having a
high energy density and an excellent charge/discharge or
oxidation/reduction cycle characteristic can be realized. Because
of these features, an electricity storage device according to the
present invention is preferably usable for vehicles such as hybrid
automobiles and mobile electronic devices. When used in the
vehicles and mobile electronic devices, an electricity storage
device according to the present invention has features of being
lightweight, having a large output, and having a long cycle life.
Therefore, devices including an electricity storage material
according to the present invention can be lightweight, which is
difficult to be realized with a conventional electricity storage
device using an inorganic compound.
[0112] In this embodiment, an electricity storage material
according to the present invention is used in an electricity
storage device, more specifically, a lithium secondary battery. As
described above, the electricity storage material according to the
present invention is also preferably usable for devices other than
secondary batteries, for example, electric double layer capacitors,
electrochemical devices such as biochips using a biochemical
reaction, and electrodes for electrochemical devices.
[0113] An electrode formed of an electricity storage material
described above can be produced by any of three methods of a dry
method, a wet method and a gas phase method. First, a method of
producing an electrode by the dry method will be described.
According to the dry method, a polymerization product represented
by any of general formulas (2) through (17) and a binder are mixed
together, and the obtained paste is pressure-contacted on a
conductive support. Thus, an electrode having a film-like
electricity storage material pressure-contacted on the conductive
support is obtained. The film may be either a fine film or a porous
film, but a film produced by the dry method is generally a fine
film.
[0114] Examples of materials usable as the binder include
fluorine-based resins such as poly(vinylidene fluoride), vinylidene
fluoride-hexafluoropropylene copolymerization product, vinylidene
fluoride-polytetrafluoroethylene and the like; and
hydrocarbon-based resins such as polyethylene, polyimide,
polyacrylic resin, cellulose-based resins and the like. From the
viewpoint of stability, fluorine-based resins are preferably
usable.
[0115] Examples of materials usable as the conductive support
include metal substrates of Al, SUS, gold, silver and the like;
semiconductor substrates of Si, GaAs, GaN and the like; transparent
conductive substrates of ITO glass, SnO.sub.2 and the like; carbon
substrates of carbon, graphite and the like; and conductive organic
substrates of polyaniline, polypyrrole, polythiophene and the
like.
[0116] The conductive support may be an independent fine film or an
independent porous film such as a mesh or a net, each of which is
formed of any of the above-described materials. Alternatively, the
conductive support may be a film of any of the above-described
conductive support materials formed on a non-conductive support of
plastic or glass. Optionally, in addition to the polymerization
product and the binder, a conduction assisting agent, for example,
may be mixed in order to improve the electron conductivity in the
film. Examples of materials usable as the conduction assisting
agent include carbon materials such as carbon black, graphite,
acetylene black and the like; and conductive polymerization
products such as polyaniline, polypyrrole, polythiophene and the
like. In the film, a solid electrolyte formed of polyethylene oxide
or the like, or a gel electrolyte formed of poly(methyl
methacrylate) or the like may be contained as an ion-conductive
assisting agent.
[0117] Now, a method of producing an electrode by the wet method
will be described. According to the wet method, a polymerization
product represented by any of general formulas (2) through (17) is
mixed in, and thus dispersed in, a solvent; the obtained slurry is
applied or printed on a conductive support; and the solvent is
removed to form a film. Optionally, a conduction assisting agent, a
binder or an ion-conductive assisting agent may be mixed in the
electrode film like in the case of the dry method. As the
conductive support, substantially the same materials as those
described above regarding the dry method are usable.
[0118] Finally, a method for producing an electrode by the gas
phase method will be described. According to the gas phase method,
a polymerization product represented by any of general formulas (2)
through (17) is gasified in vacuum, and the gas-state
polymerization product is deposited on a conductive support and is
formed into a film. Suitable film forming methods usable in this
method are general vacuum film formation processes such as vacuum
vapor deposition, sputtering, CVD and the like. Optionally, a
conduction assisting agent, a binder or an ion-conductive assisting
agent may be mixed in the electrode film like in the case of the
dry method. As the conductive support, substantially the same
materials as those described above regarding the dry method are
usable.
[0119] Hereinafter, examples of synthesizing electricity storage
materials according to the present invention, examples of producing
electricity storage devices according to the present invention, and
evaluation results of the characteristics thereof will be
described.
Example 1
[0120] First, examples of synthesizing electricity storage
materials according to the present invention will be described.
[0121] 1. Synthesis of Compound 23
[0122] Compound 23 was synthesized in accordance with reaction
formula (R7) shown below.
##STR00034##
[0123] 1.1 Synthesis of Compound 23b
[0124] Decane-1-ene (compound 23a; 126.4 g, 0.09 mol) was put into
a 2000 ml eggplant-shaped flask, and DMSO (1500 ml), distilled
water (88 ml) and NBS (320 g, 1.8 mol) were added thereto. These
substances were stirred for 4 hours. Then, extraction was caused
with ether, the extracted substance was dried, and the solvent was
removed. The obtained sample was purified by column chromatography
using silica gel. As a result, a colorless transparent liquid was
obtained. The yield was 98%.
[0125] As a result of an H-NMR (CDCl.sub.3) measurement, chemical
shifts were observed in the vicinity of .delta.3.76, 3.41, 2.20,
1.58-1.29, and 0.89 ppm. As a result of an IR (NaCl liquid film
method) measurement, peaks were observed at 3400, 2924, 2854, and
1028 cm.sup.-1. The results of the element analysis were as
follows. The theoretical values were: carbon: 50.64 wt. %,
hydrogen: 8.92 wt. %, bromine: 33.69 wt. %; whereas the
experimental values were: carbon: 50.46 wt. %, hydrogen: 9.06 wt.
%, bromine: 33.58 wt. %. It was confirmed from the above results
that the obtained liquid was compound 23b.
[0126] 1.2 Synthesis of Compound 23c
[0127] Compound 23b (210 g, 860 mmol) was put into a 2000 ml
eggplant-shaped flask and dissolved in acetone (900 ml). Sulfuric
acid (160 ml) and sodium dichromate dihydrate (260 g, 880 mmol)
were dissolved in distilled water (900 ml), and the resultant
substance was put into the eggplant-shaped flask. These substances
were stirred for 1.5 hours. Then, ether was added, and these
substances were stirred for another hour. Extraction was caused
with ether, the extracted substance was dried, and the solvent was
removed. The obtained sample was purified by column chromatography
using silica gel. As a result, a white solid was obtained. The
yield was 92%.
[0128] As a result of an H-NMR (CDCl.sub.3) measurement, chemical
shifts were observed in the vicinity of .delta.3.93, 2.65,
1.65-1.29, and 0.88 ppm. As a result of an IR (NaCl liquid film
method) measurement, peaks were observed at 2926, 2854, 1718, and
1066 cm.sup.-1. The results of the element analysis were as
follows. The theoretical values were: carbon: 51.07 wt. %,
hydrogen: 8.14 wt. %, bromine: 33.98 wt. %; whereas the
experimental values were: carbon: 50.23 wt. %, hydrogen: 7.67 wt.
%, bromine: 34.59 wt. %. It was confirmed from the above results
that the obtained white solid was compound 23c.
[0129] 1.3 Synthesis of Compound 23d
[0130] Acetone (1400 ml) was put into a 2000 ml eggplant-shaped
flask, compound 23c (150 g, 620 mmol) was added thereto, and these
substances were heated to 50.degree. C. Potassium xanthogenate (100
g, 620 mmol) was added little by little, and these substances were
refluxed for 4 hours. Then, the reaction solution was injected into
distilled water. Extraction was caused with ether, the extracted
substance was dried, and the solvent was removed. As a result, a
yellow transparent liquid was obtained. The yield was 77%.
[0131] As a result of an H-NMR (CDCl.sub.3) measurement, chemical
shifts were observed in the vicinity of .delta.4.63, 3.99, 2.59,
1.66-1.23, and 0.88 ppm. As a result of an IR (NaCl liquid film
method) measurement, peaks were observed at 2926, 2854, 1719, and
1049 cm.sup.-1. The results of the element analysis were as
follows. The theoretical values were: carbon: 56.48 wt. %,
hydrogen: 8.75 wt. %, sulfur: 23.20 wt. %; whereas the experimental
values were: carbon: 57.86 wt. %, hydrogen: 9.04 wt. %, sulfur:
21.79 wt. %. It was confirmed from the above results that the
obtained liquid was compound 23d.
[0132] 1.4 Synthesis of Compound 23e
[0133] Dehydrated toluene (1300 ml) was put into a 2000 ml
eggplant-shaped flask, compound 23d (130 g, 450 mmol) was dissolved
therein, and the resultant substance was heated to a temperature
close to the boiling point thereof. Then, diphosphorus pentasulfide
(171 g, 770 mmol) was slowly added thereto, and these substances
were refluxed for 20 hours. The obtained solution was filtrated to
remove diphosphorus pentasulfide. Extraction was caused with ether,
the extracted substance was dried, and the solvent was removed. As
a result, a yellow powder was obtained. The yield was 82%.
[0134] As a result of an H-NMR (CDCl.sub.3) measurement, chemical
shifts were observed in the vicinity of .delta.6.62, 2.59,
1.60-1.25, and 0.88 ppm. As a result of an IR (NaCl liquid film
method) measurement, peaks were observed at 3040, 2924, 2852, and
1062 cm.sup.-1. The results of the element analysis were as
follows. The theoretical values were: carbon: 53.61 wt. %,
hydrogen: 7.36 wt. %, sulfur: 39.03 wt. %; whereas the experimental
values were: carbon: 54.42 wt. %, hydrogen: 6.76 wt. %, sulfur:
39.13 wt. %. It was confirmed from the above results that the
obtained powder was compound 23e.
[0135] 1.5 Synthesis of Compound 23f
[0136] Compound 23e (3.1 g, 12 mmol) was put into a 500 ml Schlenk
tube under a nitrogen gas flow and dissolved in 140 ml of acetone.
The resultant substance was kept at a temperature of 20.degree. C.
m-chlorobenzoic acid (48 g, 300 mmol) dissolved in acetone (210 ml)
in advance was dropped thereto, and these substances were stirred
for 30 minutes. After the acetone was removed, the resultant
substance was dissolved in methylene chloride (220 ml). Sodium
hexafluorophosphate (20 g, 120 mmol) was added thereto. After these
substances were stirred at room temperature for 1 hour,
acetonitrile (200 ml) was added thereto, and these substances were
stirred for 15 minutes while the temperature was kept at 20.degree.
C. Triethylamine (56 ml) was added, and these substances were
stirred for another hour. Then, extraction was caused with ether,
the extracted substance was dried, and the solvent was removed. As
a result, an orange powder was obtained. The yield was 23%.
[0137] As a result of an H-NMR (CDCl.sub.3) measurement, chemical
shifts were observed in the vicinity of .delta.6.34, 2.36, 1.44,
1.24, and 0.84 ppm. As a result of an IR (KBr method) measurement,
peaks were observed at 3050, 2922, 2850, and 1500-1300 cm.sup.-1.
The results of the element analysis were as follows. The
theoretical values were: carbon: 61.62 wt. %, hydrogen: 8.46 wt. %,
sulfur: 29.91 wt. %; whereas the experimental values were: carbon:
61.90 wt. %, hydrogen: 8.52 wt. %, sulfur: 30.19 wt. %. It was
confirmed from the above results that the obtained powder was
compound 23f.
[0138] 1.6 Synthesis of Compound 23g
[0139] Compound 23f (0.99 g, 2.3 mmol) was put into a 100 ml
Schlenk tube under a nitrogen gas flow and dissolved in THF (25
ml). The resultant substance was cooled down to -78.degree. C.
Butyllithium (4.4 ml, 1.53 mol/L hexane solution) was dropped
thereto by a syringe, and these substances were stirred for 10
minutes. Then, perfluorohexyl diiodine (PFHI; 1.5 ml) was dropped
thereto, and these substances were stirred at -78.degree. C. for 1
hour and at room temperature for 1 hour. Distilled water was added
thereto to stop the reaction. Then, extraction was caused with
ether, the extracted substance was dried, and the solvent was
removed. The resultant substance was recrystallized with hexane. As
a result, an orange powder was obtained. The yield was 40%.
[0140] As a result of an H-NMR (CDCl.sub.3) measurement, chemical
shifts were observed in the vicinity of .delta.2.42, 1.53, 1.27,
and 0.89 ppm. As a result of an IR (KBr method) measurement, peaks
were observed at 2952, 2922, 2852, and 1500-1300 cm.sup.-1. The
results of the element analysis were as follows. The theoretical
values were: carbon: 38.83 wt. %, hydrogen: 8.46 wt. %, sulfur:
18.85 wt. %; whereas the experimental values were: carbon: 39.13
wt. %, hydrogen: 4.93 wt. %, sulfur: 19.44 wt. %. It was confirmed
from the above results that the obtained powder was compound
23g.
[0141] 1.7 Synthesis of Compound 23
[0142] Ni(cod)2 (0.28 g, 1.0 mmol) and 1,5-cod (0.11 g, 1.0 mmol)
were put into a 50 ml Schlenk tube under a nitrogen gas flow and
dissolved in 7 ml of DMF. 2,2'-bipyridine (0.19 g, 1.2 mmol) was
added thereto. After it was confirmed that the solution turned
purple, compound 23g (0.46 g, 0.67 mmol) was added thereto. These
substances were stirred at 50.degree. C. for 24 hours, and then the
reaction solution was directly put into methanol. The obtained
powder was washed, filtrated, reprecipitated using methanol, and
dried. As a result, a brown powder was obtained.
[0143] The number average molecular weight (Mn) was 3600. The
results of the element analysis were as follows. The theoretical
values were: carbon: 58.16 wt. %, hydrogen: 8.21 wt. %, sulfur:
28.24 wt. %; whereas the experimental values were: carbon: 56.31
wt. %, hydrogen: 6.96 wt. %, sulfur: 26.99 wt. %. It was confirmed
from the above results that the obtained powder was compound
23.
[0144] 2. Synthesis of Compound 25
[0145] Hereinafter, synthesis of compound 25 will be described.
2.1 Synthesis of 1-bromo-2-dodecanol
[0146] In a 1000 ml eggplant-shaped flask, 16.9 g of 1-dodecane was
dissolved in 800 ml of dimethyl sulfoxide (DMSO), and 25 ml of
H.sub.2O and 100 g of N-bromosuccinimide (NBS) were added thereto.
These substances were stirred at room temperature for 4 hours.
Then, extraction was caused with ether, the extracted substance was
dried, and the solvent was removed at reduced pressure. After the
resultant substance was purified, a colorless transparent liquid
was obtained. The yield was 59%.
2.2 Synthesis of 1-bromo-2-dodecanone
[0147] In a 1000 ml eggplant-shaped flask, 14 g of
bromo-2-dodecanol was dissolved in 110 ml of acetone. A solution
obtained in advance by dissolving 35 g of sodium dichromate
dihydrate in 150 ml of distilled water and 25 ml of sulfuric acid
was dropped thereto. These substances were stirred at room
temperature for 1.5 hours, and then 250 ml of ether was added
thereto. The resultant substance was dehydrated, and the solvent
was removed. As a result, a white solid was obtained. The yield was
80%.
2.3 Synthesis of O-ethyl-1-xanthyldodecane-2-one
[0148] In a 1000 ml eggplant-shaped flask, 9.2 g of
bromo-2-dodecanone was dissolved in 400 ml of acetone, and the
resultant substance was heated to 50.degree. C. Then, 5.6 g of
potassium xanthogenate was added thereto, and these substances were
refluxed for 4 hours. After the reflux, the reaction solution was
injected into distilled water. Extraction was caused with ether,
the extracted substance was dried, and the solvent was removed. As
a result, a yellow crystal was obtained. The yield was 45%.
2.4 Synthesis of 4-decyl-1,3-dithiol-2-thione
[0149] In a 1000 ml eggplant-shaped flask, 44 g of
O-ethyl-1-xanthyldodecane-2-one was dissolved in 600 ml of
dehydrated toluene, and the resultant substance was heated to a
temperature close to the boiling point thereof. Then, 120 g of
diphosphorus pentasulfide was added thereto little by little, and
these substances were refluxed for about 20 hours. The obtained
solution was filtrated. Extraction was caused with ether, the
extracted substance was dried, and the solvent was removed. As a
result, a red oil-like target substance was obtained. The yield was
63%.
2.5 Synthesis of 2,6-didecyltetrathiafulvalene
[0150] 3.3 g of 4-decyl-1,3-dithiol-2-thione was put into a 500 ml
Schlenk tube under a nitrogen gas flow and dissolved in 40 ml of
acetone. 48 g of m-chlorobenzoic acid dissolved in 210 ml of
acetone in advance was dropped thereto, and then these substances
were stirred for 30 minutes. After the acetone was removed, the
resultant substance was dissolved in 220 ml of methylene chloride.
When the substance became uniform, 20 g of sodium
hexafluorophosphate was added thereto. These substances were
stirred at room temperature for 1 hour, and 200 ml of acetonitrile
was added thereto. These substances were stirred for 15 minutes. 56
ml of triethylamine was added thereto, and these substances were
stirred for another hour. Then, extraction was caused with ether,
the extracted substance was dried, and the solvent was removed. The
resultant substance was purified and recrystallized. As a result,
an orange powder was obtained. The yield was 22%.
[0151] As a result of an H-NMR (CDCl.sub.3) measurement, chemical
shifts were observed in the vicinity of 5.62 (s, 4H, Sr--H), 2.27
(t, 4H, J=7.6 Hz, .alpha.-CH.sub.2--), 1.53 (m, 4H,
.beta.-CH.sub.2--), 1.29 (m, 28H, --CH.sub.2--), and 0.88 (t, 6H,
J=6.4 Hz, CH.sub.3) ppm. As a result of an IR (KBr method)
measurement, peaks were observed at 3050, 2952, 2920, 2848, and
1500-1300 cm.sup.-1. The results of the element analysis were as
follows. The theoretical values were: carbon: 64.41 wt. %,
hydrogen: 9.15 wt. %, sulfur: 26.45 wt. %; whereas the experimental
values were: carbon: 64.64 wt. %, hydrogen: 9.18 wt. %, sulfur:
26.40 wt. %. It was confirmed from the above results that the
obtained compound was 2,6-didecyltetrathiafulvalene.
2.6 Synthesis of 2,6-diiodine-3,7-didecyltetrathiafulvalene
[0152] 2,6-diiodine-3,7-didecyltetrathiafulvalene was synthesized
in accordance with formula (R8).
##STR00035##
[0153] 1.1 g of 2,6-didecyl TTF was put into a 100 ml Schlenk tube
under a nitrogen gas flow and dissolved in 25 ml of THF. The
resultant substance was cooled down to -78.degree. C. in a dry
ice-methanol bath. Then, 4.4 ml of butyllithium (BuLi) was dropped
thereto, and these substances were stirred for 10 minutes. Then,
1.5 ml of perfluorohexyl diiodine (PFHI) was dropped thereto, and
these substances were stirred at -78.degree. C. for 1 hour and at
room temperature for 1 hour. Then, distilled water was added
thereto to stop the reaction. Extraction was caused with ether, the
extracted substance was dried, and the solvent was removed. The
resultant substance was purified and recrystallized. As a result,
an orange powder was obtained. The yield was 35%.
[0154] As a result of an H-NMR (CDCl.sub.3) measurement, chemical
shifts were observed in the vicinity of 2.37 (t, 4H, J=7.6 Hz,
.alpha.-CH.sub.2--), 1.54 (m, 4H, .beta.-CH.sub.2--), 1.27 (m, 32H,
--CH.sub.2--), and 0.88 (t, 6H, J=6.4 Hz, --CH.sub.3) ppm. As a
result of an IR (KBr method) measurement, peaks were observed at
2954, 2916, 2848, and 1500-1300 cm.sup.-1. The results of the
element analysis were as follows. The theoretical values were:
carbon: 42.39 wt. %, hydrogen: 5.75 wt. %, sulfur: 17.41 wt. %,
iodine: 34.45 wt. %; whereas the experimental values were: carbon:
42.18 wt. %, hydrogen: 5.33 wt. %, sulfur: 17.75 wt. %, iodine:
36.00 wt. %. It was confirmed from the above results that the
obtained compound was
2,6-diiodine-3,7-didecyltetrathiafulvalene.
2.7 Synthesis of 2,6-diiodine-3,7-diphenyltetrathiafulvalene
[0155] 2,6-diiodine-3,7-diphenyltetrathiafulvalene was synthesized
in accordance with formula (R9).
##STR00036##
[0156] 2.8 ml of diisopropylamine and 15 ml of THF were put into a
50 ml Schlenk tube under a nitrogen atmosphere, and these
substances were kept at -78.degree. C. 13.7 ml of BuLi was added
thereto, and these substances were stirred for about 1 hour to
synthesize lithium diisopropylamide (LDA). Next, 3.0 g of
2,6-diphenyltetrathiafulvalene (produced by Aldrich) was put into
the Schlenk tube under a nitrogen gas flow and dissolved in 50 ml
of THF. The resultant substance was kept at -78.degree. C. Then,
9.33 g of perfluorohexyl diiodine was dropped thereto, and these
substances were stirred for 1 hour and at room temperature for
another hour. After the reaction, distilled water was added thereto
to stop the reaction. Then, the resultant substance was filtrated,
washed and recrystallized. As a result, a red needle-like crystal
was obtained. The yield was 52%.
[0157] As a result of an H-NMR (CDCl.sub.3) measurement, chemical
shifts were observed in the vicinity of 7.4-7.5 (phenyl group, 10H)
ppm. As a result of an IR (KBr method) measurement, peaks were
observed at 3052, 734, and 691 cm.sup.-1. The results of the
element analysis were as follows. The theoretical values were:
carbon: 35.53 wt. %, hydrogen: 1.64 wt. %, sulfur: 21.05 wt. %,
iodine: 41.78 wt. %; whereas the experimental values were: carbon:
35.43 wt. %, hydrogen: 1.68 wt. %, sulfur: 22.79 wt. %, iodine:
37.67 wt. %. It was confirmed from the above results that the
obtained compound was
2,6-diiodine-3,7-diphenyltetrathiafulvalene.
2.8 Synthesis of compound 25
(poly-(3,7-diphenyltetrathiafulvalene-3,7-didecyltetrathiafulvalene))
[0158] Compound 25 was synthesized in accordance with formula
(R10).
##STR00037##
[0159] 0.35 g of Ni(Cod).sub.2 and 0.14 g of 1,5-cod were put into
a 50 ml Schlenk tube under a nitrogen atmosphere and dissolved in
10 ml of DMF. 0.16 g of 2,2'-bipyridine was added thereto. After it
was confirmed that the solution turned purple, 0.21 g of
2,6-diiodine-3,7-diphenyltetrathiafulvalene and 0.26 g of
2,6-diiodine-3,7-didecyltetrathiafulvalene were added thereto.
These substances were stirred at 50.degree. C. for 24 hours, and
then the reaction solution was reprecipitated with methanol. The
resultant substance was filtrated and washed with ammonia water.
Then, the resultant substance was washed with an EDTA-2K aqueous
solution and hot water, reprecipitated, and dried. As a result, a
brown powder was obtained. The yield was 88%.
[0160] As a result of an H-NMR (CDCl.sub.3) measurement, chemical
shifts were observed in the vicinity of 0.88, 1.25, 2.4 (alkyl
group), 6.5, and 7.5 (phenyl group) ppm. As a result of an IR (KBr
method) measurement, peaks were observed at 2800-2700, 1600-1450,
and 1200-1300 cm.sup.-1. It was confirmed from the above results
that the obtained compound was compound 25.
[0161] 3. Synthesis of Compound 27
[0162] Compound 27 was synthesized in accordance with formula (R11)
shown below.
##STR00038##
[0163] 3.1 Synthesis of Compound 27a
[0164] Compound 27a was synthesized by substantially the same
method as compound 23g except that dodecane-1-ene was used as a
starting substance. An orange powder was obtained as compound
27a.
[0165] As a result of an H-NMR (CDCl.sub.3) measurement, chemical
shifts were observed in the vicinity of 2.37, 1.54, 1.27, and 0.88
ppm. As a result of an IR (KBr method) measurement, peaks were
observed at 2954, 2916, 2848, and 1500-1300 cm.sup.-1. The results
of the element analysis were as follows. The theoretical values
were: carbon: 42.39 wt. %, hydrogen: 5.75 wt. %, sulfur: 17.41 wt.
%; whereas the experimental values were: carbon: 42.18 wt. %,
hydrogen: 5.33 wt. %, sulfur: 17.75 wt. %. It was confirmed from
the above results that the obtained compound was compound 27a.
[0166] 3.2 Synthesis of Compound 27
[0167] Commercially available compound 27b
(2,5-bistrimethylstannylthiophene; 0.15 g, 0.36 mmol) was put into
a 50 ml Schlenk tube under a nitrogen atmosphere, and DMF (25 ml)
was added thereto. Pd(PPh.sub.3).sub.4 (40 mg, 0.035 mmol) and
compound 27a (0.26 g, 0.36 mmol) were added thereto, and these
substances were stirred at 70.degree. C. for 48 hours. After the
reaction, the reaction solution with no further treatment was put
into an aqueous solution of potassium fluoride (400 ml), and these
substances were stirred for 1 hour. This operation cycle was
repeated 3 times. 1NHCl (400 ml) was further added to wash the
resultant substance 3 times in repetition. The obtained powder was
filtrated, reprecipitated with methanol, and dried. As a result, a
red powder was obtained as compound 27. The yield was 91%.
[0168] As a result of an H-NMR (CDCl.sub.3) measurement, chemical
shifts were observed in the vicinity of 7.01, 2.85, 1.65, and 0.88
ppm. The number average molecular weight (Mn) was 6800. The results
of the element analysis were as follows. The theoretical values
were: carbon: 60.21 wt. %, hydrogen: 7.41 wt. %, sulfur: 26.80 wt.
%; whereas the experimental values were: carbon: 59.17 wt. %,
hydrogen: 7.04 wt. %, sulfur: 26.06 wt. %. It was confirmed from
the above results that the obtained compound was compound 27.
[0169] 4. Synthesis of Compound 28
[0170] Compound 28 was synthesized in accordance with formula (R12)
shown below.
##STR00039##
[0171] 4.1 Synthesis of Compound 28a
[0172] Compound 28a was synthesized in accordance with reaction
formula (R9) by the method described above in section 2.7.
[0173] 4.2 Synthesis of Compound 28
[0174] 0.366 g of commercially available
2,5-bis(trimethylstannyl)thiophene was put into a 50 ml Schlenk
tube under a nitrogen atmosphere, and 40 ml of DMF was added
thereto. 96 mg of Pd(PPh.sub.3).sub.4 and 0.5 g of compound 28a
were added thereto, and these substances were stirred at 90.degree.
C. for 48 hours. After the reaction, the reaction solution was
dropped into 500 ml of aqueous solution of potassium fluoride, and
these substances were stirred for 2 hours and then filtrated. The
resultant substance was washed with 500 ml of 1NHCl, washed with
methanol, and dried. As a result, a brown powder was obtained as
compound 28. The yield was 51%.
[0175] As a result of an H-NMR (CDCl.sub.3) measurement, chemical
shifts were observed in the vicinity of 6.61 and 1.25-0.88 ppm. The
number average molecular weight (Mn) was 4400. The results of the
element analysis were as follows. The theoretical values were:
carbon: 60.51 wt. %, hydrogen: 2.77 wt. %, sulfur: 36.72 wt. %;
whereas the experimental values were: carbon: 61.51 wt. %,
hydrogen: 2.76 wt. %, sulfur: 35.73 wt. %. It was confirmed from
the above results that the obtained compound was compound 28.
[0176] 5. Synthesis of Compound 29
[0177] Compound 29 was synthesized in accordance with formula (R13)
shown below.
##STR00040##
[0178] Compound 29a was obtained as follows. Commercially available
diphenyltetrathiafulvalene was dissolved in THF, lithium
diisopropylamide (LDA) was added thereto, and then trimethylstannyl
chloride was dropped thereto. Compound 29 was synthesized by
substantially the same method as compound using compound 29a and
compound 29b. The resultant substance was a brown powder, and the
yield was 46%.
[0179] The number average molecular weight (Mn) of the obtained
compound was 3600. The results of the element analysis were as
follows. The theoretical values were: carbon: 66.42 wt. %,
hydrogen: 5.57 wt. %, sulfur: 28.00 wt. %; whereas the experimental
values were: carbon: 64.31 wt. %, hydrogen: 5.85 wt. %, sulfur:
26.11 wt. %. It was confirmed from the above results that the
obtained compound was compound 29.
[0180] 6. Synthesis of Compound 30
[0181] Compound 30 was synthesized in accordance with formula (R14)
shown below.
##STR00041##
[0182] Compound 30 was synthesized in the same method as compound
28 except that 2,5-bis(trimethylstannyl)dithiophene was used
instead of 2,5-bis(trimethylstannyl)thiophene. The resultant
substance was a brown powder, and the yield was 68%.
[0183] The number average molecular weight (Mn) of the obtained
compound was 6600. The results of the element analysis were as
follows. The theoretical values were: carbon: 56.70 wt. %,
hydrogen: 2.56 wt. %, sulfur: 34.94 wt. %; whereas the experimental
values were: carbon: 56.21 wt. %, hydrogen: 2.62 wt. %, sulfur:
33.78 wt. %. It was confirmed from the above results that the
obtained compound was compound 30.
[0184] 7. Synthesis of Compound 34
[0185] Compound 34 was synthesized in accordance with formula (R15)
shown below.
##STR00042##
[0186] Specifically, compound 34 was synthesized by
dehydrohalogenation polycondensation of compound 34f having iodine
as a substituent at positions 4 and 5 and 1,4-diethynylbenzene
having an acetylene site.
7.1 Synthesis of compound 34a
(4,5-bis(methoxycarbonyl)-1,3-dithiol-2-thione)
[0187] Ethylene trithiocarbonate (20 g, 146 mmol) and dimethyl
acetylenedicarboxylate (21.6 ml, 176 mmol) were put into a 1000 ml
eggplant-shaped flask as a reaction vessel and dissolved in toluene
(75 ml). The resultant substance was refluxed for 6 hours. After
the reflux, hexane (200 ml) was added thereto, and a precipitate
was generated and ice-cooled. The deposited crystal was filtrated
and dried. As a result, a yellow crystal was obtained. The yield
was 29 g.
[0188] The structure of the obtained compound was identified by an
H-NMR (CDCl.sub.3) measurement and an IR measurement (NaCl liquid
film method). As a result of the H-NMR measurement, a chemical
shift was observed at 3.90 ppm. As a result of the IR measurement,
peaks were observed at 1741-1718 (0=0 vibration) and 1058 (C.dbd.S
stretching vibration) cm.sup.-1. It was confirmed from these
results that the obtained compound was compound 34a.
7.2 Synthesis of compound 34b
(4,5-bis(methoxycarbonyl)-1,3-dithiol-2-one)
[0189] Mercury acetate (7.9 g, 25 mmol) was put into a 500 ml
eggplant-shaped flask, and glacial acetic acid (65 ml) was added
thereto. Then, compound 34a (2.5 g, 10 mmol) dissolved in
chloroform (55 ml) was dropped thereto, and these substances were
stirred at room temperature for 2 hours. The resultant solution was
filtrated and neutralized with sodium hydrogen carbonate.
Extraction was caused with chloroform, the extracted substance was
dried, and the solvent was removed. As a result, 1.9 g of pale
yellow crystal was obtained. The yield was 83%.
[0190] The structure of the obtained compound was identified by an
H-NMR (CDCl.sub.3) measurement and an IR measurement (NaCl liquid
film method). As a result of the H-NMR measurement, chemical shifts
were observed in the vicinity of 3.85, 2.81, 1.70-1.22, and 0.89
ppm. As a result of the IR measurement, peaks were observed at
2952-2926 (C--H stretching vibration) and 1730 (C.dbd.O vibration)
cm.sup.-1. It was confirmed from these results that the obtained
compound was compound 34b.
7.3 Synthesis of compound 34c
(4,5-bis(hexylthio)-1,3-dithiol-2-thione)
[0191] 21.6 ml of carbon disulfide (120 mmol) was put into a 200 ml
Schlenk tube, sodium metal (2.76 g) was added thereto, and these
substances were stirred for 1 hour. Then, DMF (24 ml) was added
thereto, and these substances were refluxed overnight. After the
reflux, the resultant substance was kept at 10.degree. C., hexyl
bromide (16.9 ml) was added thereto, and these substances were
stirred at room temperature for about 1 hour. A small amount of
water was added to the obtained solution. Extraction was caused
with chloroform, the extracted substance was dried, and the solvent
was removed. As a result, an orange oil-like compound was obtained.
The yield was 21.9 g.
[0192] The structure of the obtained compound was identified by an
H-NMR (CDCl.sub.3) measurement and an IR measurement (NaCl liquid
film method). As a result of the H-NMR measurement, chemical shifts
were observed at 2.87, 1.78-1.20, and 0.90 ppm. As a result of the
IR measurement, peaks were observed at 2945-2854 (C--H stretching
vibration) and 1067 (C.dbd.S stretching vibration) cm.sup.-1. It
was confirmed from these results that the obtained compound was
compound 34c.
7.4 Synthesis of Compound 34d
(4,5-bis(hexylthio)-4',5'-bis(methoxycarbonyl)tetrathiafulvalene)
[0193] Compound 34c (2.93 g, 8.0 mmol) and compound 34b (1.87 g,
8.0 mmol) were put into a 300 ml eggplant-shaped flask and
dissolved in toluene (100 ml). Triethyl phosphite (13 ml, 80 mmol)
was added thereto, and these substances were refluxed for 16 hours.
After the reflux, the resultant substance was purified. As a
result, 1.53 g of dark red oil-like substance was obtained. The
yield was 35%.
[0194] The structure of the obtained compound was identified by an
H-NMR (CDCl.sub.3) measurement and an IR measurement (NaCl liquid
film method). As a result of the H-NMR measurement, chemical shifts
were observed in the vicinity of 3.85, 2.81, 1.70-1.22, and 0.89
ppm. As a result of the IR measurement, peaks were observed at
2952-2926 (C--H stretching vibration) and 1730 (C.dbd.O vibration)
cm.sup.-1. It was confirmed from these results that the obtained
compound was compound 34d.
7.5 Synthesis of compound 34e
(4,5-bis(hexylthio)tetrathiafulvalene)
[0195] Compound 34d (0.6 g, 1.08 mmol) was put into a 200 ml
Schlenk tube and dissolved in DMF (140 ml). Lithium bromide (8.4 g,
97.2 mmol) was added thereto, and these substances were stirred at
140.degree. C. for 3 hours. After the stirring, the resultant
substance was cooled down to room temperature. Brin (100 ml) was
added thereto. Extraction was caused with methylene chloride, the
extracted substance was dried, and the solvent was removed. As a
result, 0.36 g of brown oil-like substance was obtained. The yield
was 77%.
[0196] The structure of the obtained compound was identified by an
H-NMR (CDCl.sub.3) measurement and an IR measurement. As a result
of the H-NMR measurement, chemical shifts were observed in the
vicinity of 6.32, 2.81, 1.70-1.22, and 0.89 ppm. As a result of the
IR measurement, peaks were observed at 3066 (C.dbd.C--H vibration)
and 2952-2926 (C--H stretching vibration) cm.sup.-1. It was
confirmed from these results that the obtained compound was
compound 34e.
7.6 Synthesis of compound 34f
(4,5-bis(hexylthio)-4,5'-diiodinetetrathiafulvalene)
[0197] Diisopropylamide (0.35 ml) was put into a 25 ml Schlenk tube
at -78.degree. C. under an argon atmosphere, and THF (3 ml) was
added thereto. 1.6 M butyllithum hexane solution (1.56 ml, 2.5
mmol) was added thereto, and these substances were stirred for 1
hour. As a result, a lithium diisopropylamide (hereinafter,
referred to as "LDA") solution was obtained.
[0198] Next, compound 34e (0.36 g, 0.82 mmol) was put into a 50 ml
Schlenk tube at -78.degree. C. under a nitrogen atmosphere, and THF
(10 ml) was added thereto. LDA was dropped to this solution, and
these substances were stirred for 30 minutes. Then,
perfluorohexyldiiodine (hereinafter, referred to as "PFHI") (0.46
ml, 2.13 mmol) was added thereto, and these substances were stirred
for 1 hour and stirred at room temperature for another hour. A
small amount of water was added thereto to stop the reaction.
Extraction was caused with ether, the extracted substance was
dried, and the solvent was removed. The resultant substance was
recrystallized with hexane. As a result, a yellow powder was
obtained. The yield was 0.13 g and 23%.
[0199] The structure of the obtained compound was identified by an
H-NMR (CDCl.sub.3) measurement, an IR measurement (KBr method) and
an element analysis. As a result of the H-NMR measurement, chemical
shifts were observed in the vicinity of 2.80, 1.70-1.22, and 0.89
ppm. With the obtained compound, two peaks in the vicinity of 6.3
ppm derived from proton of the TTF ring, which were observed with
compound 34e, were not observed. From this, it is understood that
TTF was iodided. As a result of the IR measurement, peaks were
observed at 2950-2852 (C--H stretching vibration) cm.sup.-1. The
C--H stretching vibration of the TTF ring in the vicinity of 3060
cm.sup.-1, which was observed with compound 34e, was extinct. From
this also, is understood that that proton of the TTF ring was
iodided. The results of the element analysis were as follows. The
theoretical values were: carbon: 31.40 wt. %, hydrogen: 3.81 wt. %,
sulfur: 27.94 wt. %, iodine: 36.85 wt. %; whereas the experimental
values were: carbon: 31.67 wt. %, hydrogen: 3.78 wt. %, sulfur:
27.97 wt. %, iodine: 37.16 wt. %. It was confirmed from these
results that the obtained compound was compound 34f.
7.7 Synthesis of compound 34
(poly-1,2-(p-acetylphenyl-tetrathiafulvalene))
[0200] Compound 34f (138 mg, 0.2 mmol) was put into a 50 ml Schlenk
tube under a nitrogen atmosphere and dissolved in 20 ml of THF.
Copper iodide (2 mg, 0.01 mmol) and
tetrakis(triphenylsulfone)palladium (hereinafter, referred to as
"Pd(PPh.sub.3).sub.4") (12 mg, 0.01 mmol) were added thereto.
Triethylamine (15 ml) was also added thereto, and these substances
were stirred. 1,4-diethynylbenzene (25 mg, 0.2 mmol) as compound
34g was added thereto, and these substances were stirred at
60.degree. C. for 48 hours. After the reaction, the reaction
solution was transferred to methanol (500 ml), and these substances
were further stirred. The resultant substance was washed, dissolved
in THF, reprecipitated with methanol, and dried. As a result, a
black powder was obtained. The yield was 91%.
[0201] The structure of the obtained compound was identified by a
molecular weight measurement, an H-NMR (CDCl.sub.3) measurement, an
IR measurement and an element analysis. The results will be shown
below sequentially.
[0202] The molecular weight measurement of the obtained compound
was performed by GPC using THF. The obtained weight average
molecular weight was 5500 (Mw/Mn=1.49) as converted into
polystyrene. The results of the element analysis were as follows.
The theoretical values were: carbon: 60.17 wt. %, hydrogen: 5.41
wt. %, sulfur: 34.42; whereas the experimental values were: carbon:
61.45 wt. %, hydrogen: 5.09 wt. %, sulfur: 33.46 wt. %. The
experimental values and the theoretical values match each other to
a certain degree.
[0203] As a result of the H-NMR (CDCl.sub.3) measurement, all the
peaks were broader than those of a monomer, which implies that the
molecule was a polymerization product. Chemical shifts were
observed at 0.95 (--CH.sub.3), 1.15-1.80 (--(CH.sub.2).sub.4--),
2.85 (SCH.sub.3), and 7.10-7.60 (aromatic).
[0204] As a result of the IR measurement, peaks were observed in
the vicinity of 2990-2800, 2172, 2150, 1480, 1285, and 650-800
cm.sup.-1. Neither the peak in the vicinity of 3282 cm.sup.-1
derived from the triple bond stretching vibration nor the peak in
the vicinity of 2090 cm.sup.-1 derived from the 1-substituted
acetylene stretching vibration, which were observed with the
diethynyl monomer, were observed. Peaks derived from 2-substituted
acetylene stretching vibration were observed in the vicinity of
2172 and 2150 cm.sup.-1. From this, it is understood that
polymerization progressed. In the vicinity of 650-800 cm.sup.-1,
C--S stretching vibration derived from the TTF structure and
spectrum derived from ring out-plane bending vibration were
observed. From these, it was confirmed that the obtained compound
was a polymerization product having a TTF structure. From these
results, it was found that the obtained powder was compound 34.
Example 2
[0205] Hereinafter, production of electricity storage devices
according to the present invention and results of characteristic
evaluation will be described.
[0206] 1. Production of Electricity Storage Devices
[0207] 1.1 Production of Electricity Storage Device a Using
Compound 29
[0208] A positive electrode was produced as follows. As a positive
electrode active substance, poly-1,4-(p-thiol-TTF), which is a
polymerization product represented by chemical formula (29), was
used. The average molecular weight of poly-1,4-(p-thiol-TTF) used
here was about 10000, and the maximum theoretical capacity thereof
was 78 mAh/g. Poly-1,4-(p-thiol-TTF) was pulverized with a mortar
before being mixed. After being pulverized with the mortar, the
polymerization product had a particle diameter of about 10 .mu.m.
37.5 m of poly-1,4-(p-thiol-TTF) as the active substance and 100 mg
of acetylene black as a conductor were mixed uniformly, 25 mg of
polytetrafluoroethylene as a binder was added thereto, and these
substances were mixed. Thus, a positive electrode active substance
compound was obtained. The positive electrode compound was
pressure-contacted on an aluminum wire net and vacuum-dried. The
resultant material was punched into a disc having a diameter of
13.5 mm to produce positive electrode A. The weight of the positive
electrode active substance applied was 1.7 mg/cm.sup.2 per unit
area size of the electrode.
[0209] As a negative active substance, lithium metal was used.
Lithium metal (thickness: 300 .mu.m) was punched into a disc having
a diameter of 15 mm and pasted on a disc-shaped current collector
plate also having a diameter of 15 mm to produce a negative
electrode.
[0210] An electrolytic solution was produced as follows. A solvent
was produced by mixing ethylene carbonate (EC) and propylene
carbonate (PC) at a volume ratio of 1:1. The electrolytic solution
was produced by dissolving lithium hexafluorophosphate having a
concentration of 1 mol/L as a salt in the solvent. The relative
dielectric constant of the solvent used here was 78. The
electrolytic solution was used in the state of impregnating the
positive electrode, the negative electrode and a porous
polyethylene sheet (thickness: 20 km).
[0211] As described with reference to FIG. 1, the positive
electrode, the negative electrode and the electrolytic solution
were accommodated in a case of a coin-type battery and held by the
sealing plate provided with a gasket. The resultant assembly was
caulked by a press. Thus, coin-type electricity storage device A
was obtained.
[0212] 1.2 Production of Electricity Storage Device B Using
Compound 34
[0213] As a positive electrode active substance, compound 34
synthesized as described above was used. An electricity storage
device was produced by substantially the same method as electricity
storage device A except for the material of the positive electrode
active substance. Thus, electrode B and coin-type electricity
storage device B were obtained.
[0214] 1.3 Production of Electricity Storage Device C Using
Compound 23
[0215] As a positive electrode active substance, compound 23
synthesized as described above was used. An electricity storage
device was produced by substantially the same method as electricity
storage device A except for the material of the positive electrode
active substance. Thus, electrode C and coin-type electricity
storage device C were obtained.
[0216] 1.4 Production of Electricity Storage Device D Using
Compound 25
[0217] As a positive electrode active substance, compound 25
synthesized as described above was used. An electricity storage
device was produced by substantially the same method as electricity
storage device A except for the material of the positive electrode
active substance. Thus, electrode D and coin-type electricity
storage device D were obtained.
[0218] 1.5 Production of Electricity Storage Device E Using
Compound 27
[0219] As a positive electrode active substance, compound 27
synthesized as described above was used. An electricity storage
device was produced by substantially the same method as electricity
storage device A except for the material of the positive electrode
active substance. Thus, electrode E and coin-type electricity
storage device E were obtained.
[0220] 1.6 Production of Electricity Storage Device F Using
Compound 28
[0221] As a positive electrode active substance, compound 28
synthesized as described above was used. An electricity storage
device was produced by substantially the same method as electricity
storage device A except for the material of the positive electrode
active substance. Thus, electrode F and coin-type electricity
storage device F were obtained.
[0222] 1.7 Production of Electricity Storage Device G Using
Compound 30
[0223] As a positive electrode active substance, compound 30
synthesized as described above was used. An electricity storage
device was produced by substantially the same method as electricity
storage device A except for the material of the positive electrode
active substance. Thus, electrode G and coin-type electricity
storage device G were obtained.
[0224] 1.8 Production of an Electricity Storage Device as a
Comparative Example
[0225] As a comparative example, an electricity storage device
using a polymerization product represented by the following
chemical formula (36) (poly-TTF compound) as a positive electrode
active substance was produced. Poly-TTF was synthesized by reacting
poly(vinyl alcohol) and a tetrathiafulvalene carboxyl derivative by
dehydration condensation. The weight average molecular weight of
the poly-TTF used here was about 50000. The electricity storage
device of the comparative example was produced by substantially the
same method as electricity storage device A except for the
polymerization product used.
##STR00043##
[0226] 2. Evaluation of Electrodes
[0227] Electrodes A through G produced above were subjected to an
evaluation of electrochemical stability against an
oxidation/reduction reaction. The evaluation of stability was
performed by using each of electrodes A through G or the
comparative example electrode as a working electrode, lithium metal
as a counter electrode and lithium metal as a reference electrode.
These electrodes were located in a beaker cell immersed with an
electrolytic solution. The electrolytic solution was obtained by
dissolving lithium hexafluorophosphate, having a concentration of 1
mol/L as a support electrolyte salt, in propylene carbonate (PC) as
a solvent.
[0228] The stability evaluation was performed as follows. Each
working electrode was scanned over a range of potentials of 3.0 V
(lower limit) to 4.0 V (upper limit) with respect to the lithium
reference electrode. Specifically, the scanning was first performed
in a noble direction from the immersion potential at a scanning
rate of 0.05 mV/sec and the scanning was repeated between the upper
limit and the lower limit. The scanning was performed 10 times. In
order to eliminate the influence of gas adsorbed to the surface of
the electrode and of dissolved oxygen in the electrolytic solution,
the stability was evaluated by comparing the scanning result
obtained by the third scanning and the scanning result obtained by
the tenth scanning.
[0229] As a result of the measurement, electrodes A through G and
the comparative example electrode exhibited two-stage
oxidation/reduction current peaks derived from the
tetrathiafulvalene structure. It was confirmed that these
electrodes had oxidation/reduction activity. Regarding the
stability, with electrodes A through G, the oxidation/reduction
peak current value at each stage of the tenth cycle matched the
peak current value of the third cycle. By contrast, with the
comparative example electrode, the peak current values of the tenth
cycle were lower by 20% than those of the third cycle. From this,
it is considered that the electrodes of the examples have a high
stability at the time of oxidation/reduction, whereas the
oxidation/reduction activity of the comparative example electrode
is lower by 20% than that of the electrodes of the examples.
[0230] 3. Evaluation of Electricity Storage Devices
[0231] Electricity storage devices A through G and comparative
example electricity storage device were subjected to an evaluation
of charge/discharge capacity. The charge/discharge range was set to
a range of potentials at which each material can be
oxidized/reduced. Specifically, for electricity storage device A,
the upper limit of voltage for charge was set to 4.1 V, and the
lower limit of voltage for discharge was set to 3.1 V. For
electricity storage device B, the upper limit of voltage for charge
was set to 4.0 V, and the lower limit of voltage for discharge was
set to 3.2 V. For electricity storage devices C through G, the
upper limit of voltage for charge was set to 4.0 V, and the lower
limit of voltage for discharge was set to 3.0 V. The
charge/discharge operation was performed at a constant current of
0.1 mA. The pause time after the charge and before the discharge
was zero.
[0232] FIG. 3 through FIG. 9 are graphs respectively showing the
battery capacity vs. battery voltage relationship of electricity
storage devices A through G at the third cycle of the
charge/discharge operation for evaluation. As shown in FIG. 3
through FIG. 9, it was confirmed that electricity storage devices A
through G can be reversibly charged/discharged in a range of about
3 to 4 V. It was confirmed from the above results that the
polymerization products according to the present invention each act
as an active substance for an electricity storage device.
[0233] The capacity of the electricity storage device was evaluated
based on the value obtained by dividing the discharge capacity at
the third cycle of the charge/discharge operation by the weight of
the active substance, namely, based on the discharge capacity per
weight of the active substance. The ratio of the discharge capacity
of the active substance with respect to the theoretical capacity is
shown with the percentage. The evaluation of the charge/discharge
capacity was performed until the 50th cycle. The cycle
characteristic was evaluated based on the ratio of the discharge
capacity maintained at the 10th cycle and the 50th cycle, with the
discharge capacity at the third cycle being set as 100%. The
results are shown in Table 1.
TABLE-US-00001 TABLE 1 Ratio of capacity maintained after Measured
capacity repetition Theoretical Discharge Utilization [%] capacity
capacity factor 10th 50th [mAh/g] [mAh/g] [%] cycle cycle
Electricity 78 72 93 100 98 storage device A (Compound 29)
Electricity 96 90 94 100 98 storage device B (Compound 34)
Electricity 126 75 60 100 98 storage device C (Compound 23)
Electricity 128 90 70 100 99 storage device D (Compound 25)
Electricity 95 90 95 99 97 storage device E (Compound 27)
Electricity 128 121 95 100 98 storage device F (Compound 28)
Electricity 103 98 95 100 98 storage device G (Compound 30)
Comparative 180 150 80 80 40 example
[0234] As shown in Table 1, even when the charge/discharge
operation is repeated until the 50th cycle, electricity storage
devices A through G according to the present invention all had a
high capacity maintaining rate of 97% or higher, did not decrease
the capacity and exhibited a good cycle characteristic. From these
results, it is understood that the electricity storage materials
according to the present invention are compounds which are
reversibly charge/discharge-reactable. It was also found that the
electricity storage materials according to the present invention
are reversibly charge/discharge-reactable within a range of
potentials of about 3.0 to 4.0 V (with respect to lithium as the
reference).
[0235] By contrast, the comparative example electricity storage
device initially exhibited a good charge/discharge characteristic,
but the charge/discharge capacity thereof was decreased to 80% of
the initial capacity at the 10th cycle and to 40% of the initial
capacity at the 50th cycle. As a result of examination of the
present inventors, this is considered to occur for the following
reason. At an initial stage of the charge/discharge cycles, an
oxidation/reduction reaction of two electrons from the
tetrathiafulvalene structure properly occurs. However, as the
charge/discharge operation is repeated, some structural change or
environmental change around the tetrathiafulvalene structure is
caused. As a result, at the 50th cycle, an oxidation/reduction
reaction of only one electron occurs, and so the capacity is
substantially decreased.
[0236] From the above results, it has been confirmed that a good
cycle characteristic is not necessarily obtained from every
polymerization product of tetrachalcogenofulvalene but that
molecule design is very important. Namely, it has been clarified
that an electricity storage material having a good cycle
characteristic is provided by designing a polymerization product
having a tetrachalcogenofulvalene structure in a repeat unit of the
main chain as according to the present invention.
[0237] There are examples in which the discharge capacity of the
electricity storage device is lower than the theoretical capacity,
namely, the utilization factor is low. One presumable reason for
this is wettability of the electrode active substance and the
electrolytic solution. The reason is as follows. In order to cause
a charge/discharge reaction of the electrode active substance, it
is necessary to put the electrode active substance into contact
with the electrolytic solution. Where the wettability of the
electrode active substance and the electrolytic solution is low,
the entirety of the active substance may not contribute to the
reaction. This is presumed to be avoided by designing the device in
a certain manner; for example, by optimizing the composition of the
electrolytic solution.
[0238] As shown in Table 1, electricity storage devices C and D
include polymerization products in which tetrachalcogenofulvalene
structures are directly bonded to each other. Although the
theoretical capacity is as large as 126 to 128 mAh/g, the
utilization factor is limited to 60 to 70%. Among the electricity
storage devices according to the present invention, electricity
storage devices C and D have a relatively low utilization factor.
It is considered that in order to improve the utilization factor of
a polymerization product in which tetrachalcogenofulvalene
structures are directly bonded to each other, the design of the
device needs to be optimized.
[0239] By contrast, as shown in Table 1, electricity storage
devices A and E through G include polymerization products in which
tetrachalcogenofulvalene structures are bonded to each other with a
thiophene structure sandwiched therebetween. The utilization factor
is 93% or higher. From this, it is considered that a polymerization
product in which tetrachalcogenofulvalene structures are bonded to
each other with a thiophene structure sandwiched therebetween has a
high utilization factor regardless of the type of substituent other
than the tetrachalcogenofulvalene structures and so is a preferable
electrode active substance providing a large capacity. These
electricity storage devices also have a large theoretical capacity
of 78 to 128 mAh/g.
[0240] Electricity storage device B includes a polymerization
product in which tetrachalcogenofulvalene structures are bonded to
each other with a (--C.ident.C-ph-C.ident.C--) structure sandwiched
therebetween. The utilization factor is as high as 96%. Namely, a
polymerization product in which tetrachalcogenofulvalene structures
are bonded to each other with a (--C.ident.C-ph-C.ident.C--)
structure sandwiched therebetween has a high utilization factor
regardless of the type of substituent other than the
tetrachalcogenofulvalene structures and so is a preferable
electrode active substance providing a large capacity. This
electricity storage device also has a large theoretical capacity of
96 mAh/g.
[0241] As shown in Table 1, the theoretical capacity of the
electricity storage devices used in these examples is 78 to 128
mAh/g, but the theoretical capacity of an electricity storage
device according to the present invention is not limited to a value
in this range. By performing molecule design of an electricity
storage material within a range represented by general formulas (1)
through (17), an electricity storage device having a theoretical
capacity larger than this range can be realized.
[0242] For example, where the octyl group of electricity storage
device C is replaced with a methyl group, the molecule can be
easily made more lightweight, and so the capacity can be improved.
Where the octyl group of electricity storage device C is replaced
with a methyl group, the theoretical capacity is increased from 126
mAh/g to 233 mAh/g. For example, where the decyl group of
electricity storage device E is replaced with a methyl group, the
theoretical electricity storage capacity can be increased from 95
mAh/g to 172 mAh/g.
[0243] As described above, an electrode active substance according
to the present invention can provide an electricity storage device
having a large output, a large capacity and an excellent cycle
characteristic.
INDUSTRIAL APPLICABILITY
[0244] An electricity storage material according to the present
invention is lightweight, difficult to be dissolved in an organic
solvent, and reversibly oxidation/reduction-reactable stably and at
a high energy density. Therefore, the electricity storage material
according to the present invention is usable for various types of
electricity storage devices. Such electricity storage devices have
a large output, a large capacity and an excellent cycle
characteristic. Therefore, such electricity storage devices are
preferably usable for various types of mobile devices,
transportation devices, uninterruptible power supplies, etc., and
also various types of electrochemical devices including
biochips.
REFERENCE SIGNS LIST
[0245] 21 Case [0246] 22 Positive electrode current collector
[0247] 23 Positive electrode active substance layer [0248] 24
Separator [0249] 25 Sealing plate [0250] 26 Negative electrode
active substance layer [0251] 27 Negative electrode current
collector [0252] 28 Gasket [0253] 29 Electrolytic solution [0254]
31 Positive electrode [0255] 32 Negative electrode [0256] 41
Positive electrode active substance particle [0257] 42 Conductive
agent portion
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