U.S. patent application number 16/619687 was filed with the patent office on 2020-06-25 for pouch-shaped battery case having hidden-type gas pocket, pouch-shaped secondary battery including the same, and battery module i.
This patent application is currently assigned to LG Chem, Ltd.. The applicant listed for this patent is LG CHEM, LTD.. Invention is credited to Kye Yeon RYU, Han Ki YOON.
Application Number | 20200203676 16/619687 |
Document ID | / |
Family ID | 67218312 |
Filed Date | 2020-06-25 |
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United States Patent
Application |
20200203676 |
Kind Code |
A1 |
YOON; Han Ki ; et
al. |
June 25, 2020 |
Pouch-Shaped Battery Case Having Hidden-Type Gas Pocket,
Pouch-Shaped Secondary Battery Including the Same, and Battery
Module Including the Same
Abstract
A pouch-shaped battery case (and a pouch-shaped secondary
battery including the same) includes a hidden-type gas pocket
having a folded configuration such that, when gas is generated in
the pouch-shaped case, the gas pocket unfolds to form a space for
collecting the gas, whereby it is possible to reduce the extent of
swelling of the battery when the gas is generated. The gas pocket
may be configured so as not to occupy any space in a normal
operating state of the battery, such that the gas pocket is
unfolded to form the gas reception space only when the gas is
generated, whereby it is possible to improve the efficiency of
utilization of space in the battery.
Inventors: |
YOON; Han Ki; (Daejeon,
KR) ; RYU; Kye Yeon; (Daejeon, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LG CHEM, LTD. |
Seoul |
|
KR |
|
|
Assignee: |
LG Chem, Ltd.
Seoul
KR
|
Family ID: |
67218312 |
Appl. No.: |
16/619687 |
Filed: |
January 8, 2019 |
PCT Filed: |
January 8, 2019 |
PCT NO: |
PCT/KR2019/000244 |
371 Date: |
December 5, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01M 2/02 20130101; H01M
2/0207 20130101; H01M 2200/20 20130101; H01M 2/12 20130101; H01M
2002/0205 20130101 |
International
Class: |
H01M 2/02 20060101
H01M002/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 9, 2018 |
KR |
10-2018-0002860 |
Claims
1. A pouch-shaped secondary battery comprising: an electrode
assembly; and a pouch-shaped case configured to receive the
electrode assembly, wherein the pouch-shaped case includes a gas
pocket, at least a portion of which is folded, such that, when gas
is generated in the pouch-shaped case, the gas pocket is configured
to unfold to form a space for collecting the gas.
2. The pouch-shaped secondary battery according to claim 1, wherein
the pouch-shaped case includes an upper portion and a lower portion
joined together at an intermediate portion, the pouch-shaped case
being folded at the intermediate portion so that the electrode
assembly is received between the upper and lower portions, wherein
the gas pocket is disposed at the intermediate portion.
3. The pouch-shaped secondary battery according to claim 1, wherein
the pouch-shaped case has a planar, quadrangular structure defining
a perimeter having a single folded surface and three surfaces that
are attached by sealing, the gas pocket being located at the single
folded surface.
4. The pouch-shaped secondary battery according to claim 1, wherein
the pouch-shaped case includes an upper portion and a lower portion
sealed along at least a perimeter portion of the pouch-shaped case,
and wherein the gas pocket is located along at least a portion of
the perimeter portion of the pouch-shaped case.
5. The pouch-shaped secondary battery according to claim 1, wherein
the pouch-shaped case includes at least one gas pocket arranged at
at least one side of the pouch-shaped case.
6. The pouch-shaped secondary battery according to claim 1, wherein
the pouch-shaped case comprises a case main body, in which the
electrode assembly is received, with the gas pocket being formed at
one side of the case main body, the gas pocket being bent into
tight contact with the case main body.
7. The pouch-shaped secondary battery according to claim 6, wherein
the gas pocket is bent multiple times into tight contact with the
case main body.
8. The pouch-shaped secondary battery according to claim 6, wherein
the gas pocket is bent into a bellows structure that is in tight
contact with the case main body.
9. A pouch-shaped battery case comprising: a case main body
configured to receive an electrode assembly therein; and a gas
pocket positioned at least one side of the case main body, wherein
the gas pocket has a folded configuration such that, when gas is
generated from the electrode assembly, the gas pocket is configured
to unfold to form a space for collecting the gas.
10. The pouch-shaped battery case according to claim 9, wherein the
gas pocket is bent into tight contact with the case main body.
11. A battery module comprising one or more pouch-shaped secondary
batteries according to claim 1.
12. The pouch-shaped secondary battery according to claim 5,
wherein the pouch-shaped case includes at least two gas pockets
arranged at opposite sides of the pouch-shaped case from one
another.
13. The pouch-shaped secondary battery according to claim 6,
wherein the case main body includes opposing upper and lower
surfaces joined together along side surfaces that extend along a
perimeter of the upper and lower surfaces, wherein the gas pocket
is bent into tight contact with at least one of the side surfaces
of the case main body.
14. The pouch-shaped secondary battery according to claim 6,
wherein the case main body includes opposing upper and lower
surfaces joined together along side surfaces that extend along a
perimeter of the upper and lower surfaces, wherein the gas pocket
is bent into tight contact with at least one of the upper and lower
surfaces of the case main body.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a national phase entry under U.S.C.
.sctn. 371 of International Application No. PCT/KR2019/000244 filed
Jan. 8, 2019, which claims priority from Korean Patent Application
No. 10-2018-0002860 filed on Jan. 9, 2018, the disclosures of which
are incorporated herein by reference in their entirety.
TECHNICAL FIELD
[0002] The present invention relates to a secondary battery, and
more particularly to a pouch-shaped secondary battery having an
electrode assembly mounted in a pouch-shaped battery case made of a
laminate sheet and a battery module including the same.
BACKGROUND ART
[0003] In general, secondary batteries are batteries that can be
charged and discharged, unlike primary batteries, which cannot be
charged. Such secondary batteries have been widely used in
electronic devices, such as cellular phones, laptop computers, and
camcorders, or electric vehicles (EVs).
[0004] Among the secondary batteries, the use of lithium secondary
batteries has been rapidly increasing, since the capacity of the
lithium secondary battery is larger than the capacity of a
nickel-cadmium battery or a nickel-hydride battery, which are
mainly used as a power source for electronic devices, and the
energy density of the lithium secondary battery per unit weight is
high.
[0005] Such a lithium secondary battery mainly uses a lithium-based
oxide and a carbon material as a positive electrode active material
and a negative electrode active material, respectively. The lithium
ion secondary battery is configured to have a structure in which a
positive electrode sheet, to which the positive electrode active
material is applied, and a negative electrode sheet, to which the
negative electrode active material is applied, are disposed in the
state in which a separator is interposed therebetween to constitute
an electrode assembly and in which the electrode assembly is
received in a sheathing member, i.e. a battery case, together with
an electrolytic solution in a sealed state.
[0006] Depending on the shape of the battery case, the lithium
secondary battery may be classified as a can-shaped secondary
battery, configured such that the electrode assembly is mounted in
a metal can, or a pouch-shaped secondary battery, configured such
that the electrode assembly is mounted in a pouch made of an
aluminum laminate sheet.
[0007] Meanwhile, the pouch-shaped secondary battery is classified
as a unidirectional battery, configured such that electrode leads
connected to positive electrode and negative electrode tabs of the
electrode assembly are disposed at one side of the battery, or a
bidirectional battery, configured such that electrode leads
connected to positive electrode and negative electrode tabs of the
electrode assembly are disposed at opposite sides of the
battery.
[0008] In general, the pouch-shaped secondary battery includes an
electrode assembly, a pouch-shaped case configured to receive the
electrode assembly in a sealed state, and electrode leads extending
from the electrode assembly so as to be exposed out of the
pouch-shaped case.
[0009] In the pouch-shaped secondary battery described above,
however, a large amount of gas is generated due to the
decomposition of an electrolyte when the lifespan of the secondary
battery expires, the secondary battery is overcharged, the
secondary battery is exposed to high temperatures, or an internal
short circuit occurs in the secondary battery, whereby the
pouch-shaped case expands, i.e. a swelling phenomenon occurs. The
swelling phenomenon, in which the middle portion of the
pouch-shaped case swells due to gas that is generated in the
pouch-shaped case, causes the deformation of the battery. As a
result, a short circuit occurs in the battery. In severe cases,
high pressure may be generated in the sealed case, whereby the
electrolyte may be further decomposed, which may result in the
explosion of the battery.
[0010] In order to solve the above problem, Korean Patent
Application Publication No. 10-2016-0059776 and Korean Patent
Application Publication No. 10-2011-0107448 disclose various
technologies capable of dealing with the swelling phenomenon.
[0011] However, the conventional art, including the above Korean
patent application publications, is configured to have a structure
in which the interior space of a case is expanded in order to
collect gas. As a result, the overall size of a battery is
increased. In addition, since the expanded space is empty, the
expanded space is weakly resistant to external force, whereby the
expanded space may be easily deformed. In order to solve this
problem, therefore, it is necessary to install an additional
structure in the space in order to increase the rigidity of the
space, which is another problem.
DISCLOSURE
Technical Problem
[0012] The present invention has been made in view of the above
problems, and it is an object of the present invention to provide a
pouch-shaped battery case having a hidden-type gas pocket, wherein
the gas pocket is configured to be unfolded or expanded, when gas
is generated, in order to form a gas reception space, whereby it is
possible to reduce the extent of swelling of a battery when the gas
is generated, and wherein the gas pocket is configured so as not to
occupy any space in a normal state and to be unfolded only when the
gas is generated in order to form the gas reception space, whereby
it is possible to improve the efficiency of utilization of space in
the battery. The present invention also provides a pouch-shaped
secondary battery including the same, and a battery module
including the same.
Technical Solution
[0013] In accordance with an aspect of the present invention, the
above and other objects can be accomplished by the provision of a
pouch-shaped secondary battery including an electrode assembly and
a pouch-shaped case configured to receive the electrode assembly,
wherein the pouch-shaped case has therein a gas pocket configured
such that at least a portion of the gas pocket is maintained in a
folded state and such that, when gas is generated in the
pouch-shaped case, the gas pocket is unfolded to form a space
configured to collect the gas.
[0014] Here, the gas pocket may be formed at a portion of the
pouch-shaped case that is folded in order to cover the electrode
assembly at a perimeter portion of the pouch-shaped case.
[0015] The pouch-shaped case may be configured to have a
quadrangular planar structure, and in the case in which a
perimetric surface of this quadrangular plane includes a single
surface that is folded and three surfaces that are attached by
sealing, the gas pocket may be formed at the single surface that is
folded.
[0016] In addition, the gas pocket may be formed at a portion of
the pouch-shaped case that is attached by sealing at the perimeter
portion of the pouch-shaped case.
[0017] In addition, the gas pocket may be formed at at least one of
opposite side surfaces of the pouch-shaped case.
[0018] The pouch-shaped case may include a case main body, in which
the electrode assembly is mounted, and the gas pocket formed at one
side of the case main body, and the gas pocket may be configured to
have a structure in which the gas pocket is bent from the case main
body into tight contact with the case main body.
[0019] The gas pocket may be configured to have a structure in
which the gas pocket is bent multiple times into tight contact with
the case main body.
[0020] The gas pocket may be configured to have a structure in
which the gas pocket is bent so as to have a bellows structure that
is in tight contact with the case main body.
[0021] In accordance with another aspect of the present invention,
there is provided a pouch-shaped battery case including a case main
body, in which an electrode assembly is mounted, and a gas pocket
formed at at least one side of the case main body, wherein the gas
pocket is configured such that the gas pocket is maintained in a
folded state and such that, when gas is generated from the
electrode assembly, the gas pocket is unfolded to form a space
configured to collect the gas.
[0022] It is preferable that the gas pocket may be configured to
have a structure in which the gas pocket is bent from the case main
body into tight contact with the case main body.
[0023] In accordance with a further aspect of the present
invention, there is provided a battery module including one or more
pouch-shaped secondary batteries described above.
[0024] The principal technical solutions described above will be
more concretely and definitely disclosed with reference to the
following description of "best mode" and the accompanying drawings.
In addition to the principal technical solutions, various other
technical solutions according to the present invention will be
further provided and described.
Advantageous Effects
[0025] A pouch-shaped battery case having a hidden-type gas pocket
according to the present invention, a pouch-shaped secondary
battery including the same, and a battery module including the same
have effects in that, when gas is generated from an electrode
assembly, the gas pocket, which is maintained in a folded state, is
unfolded or expanded to form a gas reception space, whereby it is
possible to reduce the extent of swelling of the battery case when
the gas is generated, and in particular, the gas pocket is
configured so as to occupy little space in a normal state and to be
unfolded to form the gas reception space only when the gas is
generated, whereby it is possible to improve the efficiency of
utilization of space in the battery.
DESCRIPTION OF DRAWINGS
[0026] FIGS. 1 to 4 are views showing a pouch-shaped secondary
battery having a hidden-type gas pocket according to a first
embodiment of the present invention, wherein
[0027] FIG. 1 is a perspective view,
[0028] FIG. 2 is a sectional view taken along line A-A of FIG.
1,
[0029] FIG. 3 is front views showing the operation of the gas
pocket, and
[0030] FIG. 4 is sectional views taken along lines B-B, C-C, and
D-D of FIG. 3;
[0031] FIGS. 5 and 6 are views showing a pouch-shaped secondary
battery having a hidden-type gas pocket according to a second
embodiment of the present invention, wherein
[0032] FIG. 5 is a cross-sectional view, and
[0033] FIG. 6 is sectional views of principal parts showing the
operation of the gas pocket;
[0034] FIG. 7 is a cross-sectional view showing a pouch-shaped
secondary battery having a hidden-type gas pocket according to a
third embodiment of the present invention;
[0035] FIG. 8 is a cross-sectional view showing a pouch-shaped
secondary battery having a hidden-type gas pocket according to a
fourth embodiment of the present invention;
[0036] FIG. 9 is a cross-sectional view showing a pouch-shaped
secondary battery having a hidden-type gas pocket according to a
fifth embodiment of the present invention; and
[0037] FIG. 10 is a cross-sectional view showing a pouch-shaped
secondary battery having a hidden-type gas pocket according to a
sixth embodiment of the present invention.
BEST MODE
[0038] Hereinafter, exemplary embodiments of the present invention
will be described with reference to the accompanying drawings.
[0039] FIGS. 1 to 4 are views showing a pouch-shaped secondary
battery having a hidden-type gas pocket according to a first
embodiment of the present invention, wherein FIG. 1 is a
perspective view, FIG. 2 is a sectional view taken along line A-A
of FIG. 1, FIG. 3 is front views showing the operation of the gas
pocket, and FIG. 4 is sectional views taken along lines B-B, C-C,
and D-D of FIG. 3.
[0040] As shown in FIGS. 1 to 4, the pouch-shaped secondary battery
having the hidden-type gas pocket according to the first embodiment
of the present invention includes an electrode assembly 10 and a
pouch-shaped case 20 configured to receive the electrode assembly
10. In addition, the secondary battery is configured such that
electrode leads 15 are exposed out of the pouch-shaped case 20.
[0041] Here, the electrode assembly 10 is a power-generating
element configured to have a structure including a positive
electrode, a negative electrode, and a separator interposed between
the two electrodes. The electrode assembly 10 may be constructed
using a well-known electrode assembly 10, and therefore a detailed
description thereof will be omitted.
[0042] The pouch-shaped case 20 may be made of a laminate sheet
configured to cover the outside of the electrode assembly 10 in a
sealed state. Preferably, the laminate sheet is made of a metal
material, such as aluminum.
[0043] The structure in which the electrode assembly 10 is sealed
using the pouch-shaped case 20 may be variously constructed. In
this embodiment, the pouch-shaped case 20 has a quadrangular
sealing structure, since the electrode assembly 10 generally has a
quadrangular planar structure.
[0044] This pouch-shaped case 20 is configured to have a structure
in which an approximately middle portion thereof is folded, the
electrode assembly 10 is located therebetween, and the other open
three perimetric surfaces thereof are sealed except for the folded
portion. Consequently, the pouch-shaped case 20 covers the upper
surface and the lower surface of the electrode assembly 10 in the
state in which the electrode assembly 10 is located therein, and
the four perimetric surfaces of the pouch-shaped case, which
constitute a quadrangular plane, include a single surface 22 that
is folded (hereinafter, also referred to as a `folded surface`) and
three surfaces 24 and 25 that are attached by sealing (hereinafter,
also referred to as `sealed surfaces`).
[0045] Here, the sealed surfaces 24 and 25 may be portions that are
sealed by adhering the overlapping portions of the laminate sheet
constituting the pouch-shaped case 20 closely to each other by
thermal welding.
[0046] In particular, a gas pocket 30 configured to collect gas
generated from the electrode assembly 10 due to various causes is
provided at the folded surface 22 of the pouch-shaped case 20. The
gas pocket 30 will be described hereinafter in detail with
reference to FIGS. 2 to 4.
[0047] Meanwhile, FIG. 1 illustrates the structure in which the
electrode leads 15 are installed at opposite ends of the
pouch-shaped case 20 so as to be exposed. However, the direction in
which the electrode leads 15 are exposed and the number of
electrode leads 15 may be variously changed depending on the
embodiment conditions. For example, both the electrode leads 15 may
be exposed at one end of the pouch-shaped case 20.
[0048] Now, the gas pocket 30 will be described below in detail
with reference to FIGS. 2 to 4.
[0049] In this embodiment, the gas pocket 30 is provided at the
folded surface 22 of the pouch-shaped case 20. The gas pocket 30 is
configured such that the gas pocket 30 is maintained in a folded
state at the side surface of the pouch-shaped case 20 and such
that, when gas is generated in the pouch-shaped case 20, the gas
pocket 30 is unfolded to form a space configured to collect the
gas.
[0050] Referring to FIG. 2 and the like, the folded structure of
the gas pocket 30 is configured to have a structure in which the
gas pocket 30 is provided at the folded surface 22 of the
pouch-shaped case 20 connected to a case main body 21, in which the
electrode assembly 10 is mounted, in which the gas pocket 30 is
formed so as to be bent multiple times, like a rolled structure, in
the state in which the folded surface 22 is in tight contact in a
double-folded state, and in which the gas pocket 30 is in tight
contact with the side surface of the case main body 21 in this
state.
[0051] Referring to the figures showing the present embodiment, the
gas pocket 30 is configured to have a structure in which the gas
pocket 30 is bent two or three times from the middle portion of the
side surface of the case main body 21 and is then in tight contact
with the side surface of the case main body 21.
[0052] For reference, in all the figures showing the embodiment of
the present invention, the folded structure of the gas pocket 30 is
somewhat widened. However, the gas pocket 30 is shown as described
above in order to clearly show the folded structure thereof.
Consequently, it is desirable to understand that the folded
portions of the gas pocket 20 are assembled in the state of being
in tight contact with each other or with the case main body 21.
[0053] The gas pocket 30 may be configured such that the
pouch-shaped case 20 is bent in the state of being simply in tight
contact in a double-folded structure and is then in tight contact
with the side surface of the case main body 21. As needed, however,
the overlapping portions, among the portions constituting the gas
pocket 30, may be sealed at low strength, and may then be brought
into tight contact with the side surface of the case main body 21.
At this time, the sealing strength of the gas pocket 30 may be
lower than the sealing strength of the other three sealed surfaces
24 and 25 by a predetermined level such that, when gas is generated
in the pouch-shaped case, the sealed portion of the gas pocket 30
is widened to collect the gas.
[0054] The process of collecting the gas generated in the
pouch-shaped case using the gas pocket 30 will be described with
reference to FIGS. 3 and 4.
[0055] FIGS. 3(a) and 4(a) show the state of the gas pocket 30 in
the normal state, i.e. when no gas is generated. The gas pocket 30
is in tight contact with the side surface of the case main body 21
in an initially assembled state, i.e. in a folded state. At this
time, the gas pocket 30 occupies only the external volume
corresponding to the size of the laminate sheet that is bent
multiple times and is then in tight contact, whereby the overall
size of the battery is scarcely increased.
[0056] When gas is generated in the battery in the state in which
the gas pocket 30 is folded as described above, as shown in FIGS.
3(b) and 4(b), the gas is introduced into the gas pocket 30,
whereby the folded gas pocket 30 starts to be unfolded. In the
figures, the state in which the gas pocket 30 is unfolded in a
straight line is illustrated for the sake of convenience. However,
the gas pocket 30 may be unfolded in various shapes depending on
several conditions. For example, the gas pocket 30 may expand while
being unfolded from the entrance thereof, or the bent portion of
the gas pocket 30 may be unfolded later.
[0057] Subsequently, when gas is continuously generated in the
battery, the gas pocket 30 continuously swells. When the gas pocket
30 fully swells, as shown in FIGS. 3(c) and 4(c), the gas pocket 30
expands at the side surface of the battery to form a maximum gas
collection space S.
[0058] The maximum gas collection space S in the gas pocket 30 may
be appropriately set depending on embodiment conditions. By the
provision of the gas pocket 30, it is possible to minimize the
deformation of the remaining portion of the battery, excluding the
portion of the battery at which the gas pocket is located, when gas
is generated in the battery. In particular, it is possible to
sufficiently secure the gas collection space, whereby it is
possible to prevent explosion of the battery.
[0059] Hereinafter, various embodiments of the gas pocket according
to the present invention will be described. For reference,
components of the following embodiments that are identical or
similar to the components of the first embodiment are denoted by
the same reference numerals, a duplicate description thereof will
be omitted if possible, and a description will be given based on
components of the following embodiments that are different from the
components of the first embodiment.
[0060] FIGS. 5 and 6 are views showing a pouch-shaped secondary
battery having a hidden-type gas pocket according to a second
embodiment of the present invention, wherein FIG. 5 is a
cross-sectional view and FIG. 6 is sectional views of principal
parts showing the operation of the gas pocket.
[0061] In the first embodiment of the present invention previously
described, the gas pocket 30 is provided only at the folded portion
of the pouch-shaped case 20, i.e. the folded surface 22. In the
second embodiment of the present invention, however, the
construction in which the gas pocket 30 may also be formed at the
sealed portion of the pouch-shaped case 20, i.e. the sealed surface
24, is shown.
[0062] That is, referring to FIGS. 5 and 6, the gas pocket 30
according to the second embodiment of the present invention may be
provided at opposite sides of the pouch-shaped case 20. At this
time, since the one side surface of the pouch-shaped case 20 is the
folded surface 22 and the other side surface of the pouch-shaped
case 20 is the sealed surface 24, a gas pocket 31 at the folded
surface 22 may be configured as in the first embodiment, which was
previously described, and a gas pocket 32 at the sealed surface 24
may be configured such that only the ends of the double-folded
portions of the gas pocket are joined by sealing and the remainder
of the double-folded portions of the gas pocket are folded in the
state of being in tight contact with each other in order to
constitute the gas pocket 30.
[0063] Here, it may be considered that the sealed surface 24, at
which the gas pocket 32 is formed, is formed so as to have a
smaller width of the sealing attachment surface than the other
sealed surfaces 25 (see FIG. 1), at which no gas pocket 30 is
formed. This serves to enlarge the gas collection space of the gas
pocket 32 while the sealing area thereof is minimized.
[0064] FIGS. 6(a), 6(b), and 6(c) sequentially show the folded and
assembled state of the gas pocket 32, the state in which the gas
pocket 32 starts to be unfolded, and the maximum gas collection
state of the gas pocket 32.
[0065] In the structure in which the gas pocket 32 is also formed
at the sealed surface 24 of the pouch-shaped case 20, as described
above, the gas pocket 30 may not be formed at the folded surface 22
of the pouch-shaped case 20, and the gas pocket 32 may be formed at
only the sealed surface 24 of the pouch-shaped case 20. In
addition, in the case in which the pouch-shaped case 20 is
constituted by two laminate sheets and thus all surfaces of the
pouch-shaped case are attached to each other by sealing without
being folded, the gas pocket 32 shown in FIG. 6(a) may be provided
at at least one sealed surface of the pouch-shaped case.
[0066] FIG. 7 is a cross-sectional view showing a pouch-shaped
secondary battery having a hidden-type gas pocket according to a
third embodiment of the present invention. Unlike the previously
described first and second embodiments of the present invention, in
each of which the gas pocket 30 starts to be formed from the middle
portion of the side surface of the battery, this embodiment is
configured to have a structure in which a gas pocket 30 starts to
be formed at the corner at which the side surface of the
pouch-shaped case 20 meets another surface (the upper surface or
the lower surface) of the pouch-shaped case and is then folded so
as to cover the side surface of the battery.
[0067] The gas pocket 30 (31a and 32a) may be formed at one of the
opposite side surfaces of the battery.
[0068] The other components of this embodiment may be configured so
as to be identical or similar to the components of the embodiments
that were previously described, and therefore a duplicate
description thereof will be omitted.
[0069] FIG. 8 is a cross-sectional view showing a pouch-shaped
secondary battery having a hidden-type gas pocket according to a
fourth embodiment of the present invention. This embodiment is
similar in construction to the third embodiment, except that, in
the case in which sealed surfaces 24 are formed at both opposite
sides of the battery, a gas pocket 32a is provided at each of the
sealed surfaces 24.
[0070] In addition, the opposite gas pockets 32a start to be formed
from opposite sides in the diagonal direction.
[0071] FIG. 9 is a cross-sectional view showing a pouch-shaped
secondary battery having a hidden-type gas pocket according to a
fifth embodiment of the present invention. Unlike the embodiments
previously described, a gas pocket 30 is formed as the result of
being bent toward the upper surface or the lower surface of the
battery, rather than toward the side surface of the battery.
[0072] In this embodiment, the gas pocket 30 (33 and 34) may be
formed at only one of the opposite sides of the battery.
[0073] FIG. 10 is a cross-sectional view showing a pouch-shaped
secondary battery having a hidden-type gas pocket according to a
sixth embodiment of the present invention. This embodiment shows
the construction in which a gas pocket 30 is formed at the side
surface of the battery so as to have a bellows structure.
[0074] In this embodiment, a gas pocket 35 having the same
structure may be formed at the sealed surface of the battery, or
the gas pocket 35 may be formed at opposite sides of the
battery.
[0075] In addition, since the gas pocket 35 is formed so as to have
a bellows structure, bellows parts constituting the bellows
structure may be attached to each other via an adhesive member such
that the gas pocket 35 is stably fixed in tight contact with the
side surface of the battery before gas is generated.
[0076] Meanwhile, a battery module may be configured to include one
or more pouch-shaped secondary batteries described above. The
battery module is configured to include at least one pouch-shaped
secondary battery cell. A plurality of pouch-shaped secondary
battery cells may be combined in order to constitute the battery
module. In addition, a plurality of battery modules may be combined
in order to manufacture a battery pack.
[0077] The technical ideas described with reference to the
above-described embodiments of the present invention may be
embodied independently or in a combined state. In addition,
although the present invention has been described with reference to
the embodiments disclosed in the drawings and the detailed
description of the invention, the embodiments are merely
illustrative. Those skilled in the art to which the present
invention pertains will appreciate that various modifications and
other equivalent embodiments can be devised based on the
embodiments described above. Therefore, the technical protection
scope of the present invention is to be defined by the appended
claims.
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