JP2016157538A - Power storage device and manufacturing method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage device and a manufacturing method for the same that can prevent burst of an exterior member while enhancing the sealing performance of the exterior member.SOLUTION: A power storage device 1 includes an exterior member 12 and a laminate body 119. The exterior member 12 includes a first adhesion portion 123 formed by adhesively attaching at least the whole outer edge portion of an overlap portion of a film member formed at the peripheral portion of the film member, and an area S1 which is hermetically sealed by the film member and the first adhesion portion 123. The laminate body 119 is mounted in the area S1 of the exterior member 12. The exterior member 12 has two second adhesion portions 123a which are disposed at the laminate body 119 side along the boundary between the area S1 and the first adhesion portion 123 and formed by adhesively attaching the overlap portion. The two second adhesion portions 123a have through-holes 16 which penetrate through the second adhesion portions 123a and are sized so that the adhesively attached areas remain around the through-holes.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a power storage device and a method for manufacturing a power storage device.

  In recent years, an electricity storage device using a laminate-type exterior member has been provided in response to demands for weight reduction and thickness reduction.

  In this type of electricity storage device, when a voltage outside the standard range is applied during use or when the temperature temporarily rises, the internal electrolyte may be decomposed to generate gas. If a large amount of gas is generated and the internal pressure of the exterior member rises abnormally, the exterior member may burst.

  On the other hand, conventionally, one stress concentration portion in which peeling stress is concentrated in the sealing region when gas is generated inside the exterior member is formed in a part of the sealing region of the laminate type exterior member that houses the battery element. An electric device (electric storage device) that has been formed and provided with one through hole as a pressure release portion in the stress concentration portion has been proposed (see Patent Document 1). In this electricity storage device, the shortest distance between the inside of the exterior member and the through hole determines the internal pressure of the exterior member when the gas inside the exterior member is released to the outside through the through hole (gas release internal pressure). Specifically, the shorter the shortest distance, the lower the internal pressure during gas discharge.

JP 2005-203262 A

  In the configuration described in Patent Document 1, in order to reduce the internal pressure at the time of gas discharge, it is necessary to set the shortest distance short. However, if the above-mentioned shortest distance is too short, the sealing performance of the exterior member is lowered, and moisture or the like may enter from the outside to the inside of the exterior member, thereby reducing the battery performance. On the other hand, if the above-mentioned shortest distance is lengthened to sufficiently secure the sealing performance of the exterior member, the internal pressure at the time of gas release increases, and the exterior member may burst. When the exterior member ruptures, the electrolyte solution, electrodes, and the like inside the exterior member are scattered.

  The present invention has been made in view of the above-described reasons, and an object thereof is to provide an electricity storage device and a method for manufacturing the electricity storage device that can prevent the exterior member from bursting while improving the sealing performance of the exterior member. .

The electricity storage device according to the present invention is:
A first adhesive portion formed by adhering at least the entire outer edge of the overlapping portion of the film member formed on the periphery of the film member, and sealed by the film member and the first adhesive portion. An exterior member having a region;
A battery element housed in a region sealed by the first adhesive portion, and an electricity storage device comprising:
The exterior member is
A plurality of second adhesive portions formed by adhering the overlapping portions disposed on the battery element side along a boundary between the region sealed by the first adhesive portions and the first adhesive portion; ,
Each of the plurality of second adhesive portions has a through-hole having a size that penetrates the second adhesive portion and leaves a region bonded around the second adhesive portion.

A method for manufacturing an electricity storage device according to the present invention includes:
An overlapping part forming step of surrounding the battery element from both sides sandwiching the battery element with a film member and providing an overlapping part on a peripheral part of the film member;
A region where the battery element is arranged is formed by adhering at least the entire edge of the overlapping portion opposite to the battery element side to form a first adhesive portion, and the first adhesive portion Forming a plurality of second adhesive portions arranged on the battery element side along a boundary between the battery element and the region where the battery element is arranged;
A through-hole drilling step of drilling a through-hole having a size that penetrates the second adhesive portion and leaves a region bonded around the second adhesive portion.

  According to the present invention, a plurality of second adhesive portions are provided, and through holes are provided in each of the plurality of second adhesive portions. Thereby, even if the shortest distance between the region of the exterior member and the through-hole is increased to some extent, an excessive increase in the internal pressure during gas release can be suppressed, so that the exterior member can be ruptured while improving the sealability of the exterior member. Can be prevented.

1 is an exploded perspective view showing a configuration of an electricity storage device according to Embodiment 1. FIG. 3 is a plan view of the electricity storage device according to Embodiment 1. FIG. (A) is an AA line cross-sectional arrow view in FIG. 2, (b) to (d) are cross-sectional views at each step in the method for manufacturing an electricity storage device according to the first embodiment. 1 is a cross-sectional view illustrating a configuration of an electricity storage device according to Embodiment 1. FIG. It is a figure which shows the result of having evaluated the gas emission performance of the electrical storage device which concerns on Embodiment 1. FIG. 6 is a plan view of an electricity storage device according to Embodiment 2. FIG. It is a top view of the electrical storage device concerning a modification. It is a top view of the electrical storage device concerning a modification. It is a top view of the electrical storage device concerning a modification. It is a top view of the electrical storage device concerning a modification.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
As shown in FIG. 1, the electricity storage device 1 according to the present embodiment includes a stacked body (battery element) 119 in which a positive electrode and a negative electrode are stacked via a separator, and the stacked body 119 extends in the stacking direction of the stacked body 119. The positive electrode external terminal 111 extending in the orthogonal direction, the negative electrode external terminal 112, and the exterior member 12 that covers the laminate 119 are provided. The positive electrode external terminal 111 is electrically connected to the positive electrode of the multilayer body 119 via the extraction electrode portion 117a and the joint portion 117b. The negative electrode and the negative electrode external terminal 112 are electrically connected to the negative electrode of the multilayer body 119 via the extraction electrode portion 118a and the joint portion 118b. Details of the structure of the stacked body 119 will be described later. The exterior member 12 includes film members 125a and 125b.

  The exterior member 12 includes a first adhesive portion 123 formed by bonding the film members 125a and 125b, and a laminate housing portion (battery element housing portion) 121 that houses the laminate 119 in an inner region. The first adhesive portion 123 is opposite to the laminated body 119 side in the overlapping portion of the film members 125a and 125b formed on the periphery of the film members 125a and 125b surrounding the laminated body 119 from both sides of the laminated body 119. It is formed by adhering at least the entire edge portion by a heat fusion method. The stacked body storage unit 121 has a rectangular shape in plan view. Overlap portions 122 a and 122 b where the film members 125 a and 125 b overlap are formed on the periphery of the exterior member 12. The spacers 14 are interposed between the regions 126a and 126b corresponding to the non-bonded portions that are not thermally fused in the overlapping portions 122a and 122b. The first adhesive portion, the second adhesive portion, and the non-adhesive portion are formed by performing heat fusion processing on the overlap portions 122a and 122b with the three spacers 14 sandwiched between the overlap portions 122a and 122b. Is done.

  The film members 125a and 125b have a heat-fusible resin layer and a metal thin film layer. As the resin used for the heat-fusible resin layer, a resin capable of heat-sealing such as polypropylene can be used. The thickness of the heat-fusible resin layer is set to, for example, 10 μm to 200 μm. As the metal thin film layer, for example, a foil such as aluminum having a thickness of 10 μm to 100 μm can be used. In addition, three spacers 14 made of a heat resistant resin such as polyimide are disposed between the overlapping portions 122a and 122b.

  FIG. 2 is a plan view of the electricity storage device according to the first embodiment. As shown in FIG. 2, a first adhesive part 123 and a second adhesive part 123 a (formed by heat-sealing part of the film members 125 a and 125 b on the outer peripheral part 122 of the multilayer body accommodating part 121. 2) and a non-adhesive portion 124 that can communicate with the inside of the stacked body storage portion 121. Here, “can communicate” occurs between the inner surface of the film members 125 a and 125 b and the spacer 14 when the internal pressure of the exterior member 12 increases and the film members 125 a and 125 b bulge away from each other. It means to communicate through a gap.

  The second bonding portion 123 a and the non-bonding portion 124 are disposed on the stacked body 119 side along the boundary between the region S <b> 1 inside the stacked body storage section 121 and the first bonding section 123. The second bonding portion 123a has, for example, a substantially rectangular shape in plan view, and the non-bonding portions 124 are located on both sides in the direction along the boundary. The second bonding portion 123a is formed by bonding the overlapping portions 122a and 122b with the spacer 14 interposed in the overlapping portions 122a and 122b between the film member 125a and the film member 125b. Here, the part where the spacer 14 is interposed in the overlapping parts 122a and 122b corresponds to the non-bonding part 124, and the other part in the overlapping parts 122a and 122b corresponds to the first bonding part 123 or the second bonding part 123a. . This corresponds to a portion where the spacer 14 is interposed in the outer peripheral portion 122 of the stacked body storage portion 121. The three spacers 14 are arranged in a state where part of the three spacers 14 protrudes to the inside of the stacked body storage unit 121. Thereby, the non-bonding part 124 is in a state of communicating with the inside (region S1) of the stacked body storage part 121. A portion of the first bonding portion 123 corresponding to the space between the three non-bonding portions 124 corresponds to the second bonding portion 123 a adjacent to the non-bonding portion 124. The width L4 of the first bonding portion 123 on one side where the second bonding portion 123a of the exterior member 12 is provided is narrower than the width L3 of the first bonding portion 123 on one side where the second bonding portion 123a is not provided. ing.

  The 2nd adhesion part 123a is provided along the long side of exterior member 12 of a plane view rectangle. Fig.3 (a) is the AA sectional view taken on the line in FIG. As shown in FIG. 2 and FIG. 3 (a), the two second adhesive portions 123a penetrate through the overlapping portions 122a and 122b of the film members 125a and 125b, respectively, so that a region adhered to the periphery remains. It has a hole 16. The shortest distance (shortest adhesion width) W0 between the inner region S1 of the stacked body storage unit 121 and the through hole 16 is set to 2 mm, for example.

  FIG. 4 is a cross-sectional view of the electricity storage device 1 according to the first embodiment. As shown in FIG. 4, the laminate 119 includes a plurality (three in FIG. 2) of positive electrodes 113, a plurality (two in FIG. 1) of negative electrodes 114, and a separator 116 that separates the positive electrodes 113 and the negative electrodes 114 from each other. Have a laminated structure. A region S1 inside the exterior member 12 is filled with a non-aqueous electrolyte. The stacked body 119 is disposed in the region S1 filled with the nonaqueous electrolytic solution. The non-adhesion portion 124 communicates with the region S1, and the non-adhesion portion 124 is also filled with a non-aqueous electrolyte.

  The non-aqueous electrolyte is an organic electrolyte obtained by dissolving an electrolyte containing a lithium salt such as LiPF6 in an organic solvent such as ethylene carbonate.

  The positive electrode 113 has a positive electrode active material layer formed on the front and back surfaces of a thin plate-shaped positive electrode current collector formed of, for example, a porous aluminum foil. The positive electrode active material is composed of a carbon material such as natural graphite, artificial graphite, non-graphitizable carbon, graphitizable carbon, low-temperature calcined carbon, activated carbon and the like. Each positive electrode 113 is continuous with the extraction electrode portion 117a. The three extraction electrode portions 117a are connected to the positive electrode external terminal 111 in a state where they are bundled together by the joint portion 117b.

  The negative electrode 114 is formed by forming a negative electrode active material layer on the front and back surfaces of a thin plate-shaped negative electrode current collector formed of, for example, a porous copper foil. The negative electrode active material is composed of, for example, artificial graphite that absorbs or desorbs lithium ions. Each negative electrode 114 is continuous with the extraction electrode portion 118a. The two extraction electrodes 118a are connected to the negative external terminal 112 in a state where they are bundled together by the joint portion 118b.

  The separator 116 is formed of, for example, a film having a thickness of 50 μm and a porosity of about 70% from the viewpoint of preventing contact between the positive electrode 113 and the negative electrode 114 and allowing permeation of ions while ensuring insulation. The separator 116 is composed of a sheet-like member that can be impregnated with a nonaqueous electrolytic solution such as a cellulose-based nonwoven fabric.

Next, the operation of the electricity storage device 1 according to the present embodiment will be described.
When a voltage outside the standard range is applied to the laminate 119 during use of the electricity storage device 1 or when the temperature is temporarily increased, gas is generated inside the exterior member 12 and the inside of the laminate housing portion 121 (region S1). ) And the internal pressure of the non-bonding portion 124 increases. When the internal pressure of the laminated body storage part 121 and the internal pressure of the non-adhesive part 124 rise, peeling stress acts on the second adhesive part 123a, and the second adhesive part 123a progresses from the side closer to the laminated body 119. . When the separation reaches the through hole 16 in each of the two second adhesive portions 123a, in the second adhesive portion 123a, the gas filled inside the stacked body storage portion 121 is released to the outside of the exterior member 12 through the through hole 16. The The degree of peeling depends on the magnitude of the peeling stress. When the internal pressure of the stacked body storage unit 121 rises, the two second bonding portions 123 a generate a large peeling stress as compared with other portions of the first bonding portion 123. Therefore, when the internal pressure of the stacked body storage unit 121 rises, the peeling proceeds from the second adhesive portion 123a. And the inner side of the laminated body accommodation part 123a is connected to the exterior of the exterior member 12 through the through-hole 16 first drilled in the second adhesive part 123a. The internal pressure at the time of gas release is determined by the shortest distance (shortest adhesive width) W0 between the through hole 16 formed in the second adhesive portion 123a having the largest peeling stress and the inside of the laminate housing portion 121.

  Here, the result of having evaluated the gas discharge | release performance of the electrical storage device 1 which concerns on this Embodiment is demonstrated. The gas discharge performance of the electricity storage device 1 is evaluated by supplying gas into the exterior member 12 to increase the internal pressure of the exterior member 12 and measuring the internal pressure immediately before the internal gas is released to the outside. went. Hereinafter, this measured pressure is referred to as “gas release internal pressure”.

  The power storage device 1 according to the present embodiment used for the evaluation has two second adhesive portions 123a, and the through holes 16 are formed in each of the two second adhesive portions 123a. Here, the exterior member 12 has a rectangular shape in plan view, and includes two film members 125a and 125b having a length of 140 mm and a width of 140 mm. Moreover, with reference to FIG. 2, the width L3 of the outer peripheral part 122 of the laminated body accommodating part 121 was set to 10 mm. The length L1 in the alignment direction of each of the three non-adhesive portions 124 having a substantially rectangular shape in plan view is 10 mm, the length d in the direction orthogonal to the alignment direction is 5 mm, and the distance L2 in the alignment direction between adjacent non-adhesive portions 124 is It is set to 6 mm. The diameter of the through hole 16 is 2 mm, and the shortest adhesion width W0 of the through hole 16 is 2 mm.

  The electricity storage device according to Comparative Example 1 had one second adhesive portion, and one through hole was formed in the second adhesive portion. The width of the outer peripheral portion 122 of the laminate housing portion 121, the shape and size of the non-adhesive portion, the diameter of the through hole, and the shortest adhesion width of the through hole were the same as those of the electricity storage device 1 according to the above-described embodiment. The electricity storage device according to Comparative Example 2 was assumed to have no second adhesive portion and through hole. The width of the outer peripheral portion 122 of the laminate housing portion 121, the shape and size of the non-adhesive portion, the diameter of the through hole, and the shortest adhesion width of the through hole were the same as those of the electricity storage device 1 according to the above-described embodiment. Five electrical storage devices according to the present embodiment, Comparative Example 1 and Comparative Example 2 were prepared, and the internal pressure during gas release was measured for each of the electrical storage devices.

  In the electricity storage device according to Comparative Example 1, as shown in FIG. 5, the maximum value of the internal pressure at the time of gas release is 251.9 kPa, the minimum value is 193.1 kPa, the average value is 233.0 kPa, and the difference between the maximum value and the minimum value The (pressure difference) was 58.8 kPa. In the electricity storage device according to Comparative Example 2, the maximum value of the internal pressure during gas release was 379.3 kPa, the minimum value was 347.8 kPa, the average value was 367.8 kPa, and the pressure difference was 31.5 kPa. On the other hand, in the electricity storage device 1 according to the present embodiment, the maximum value of the internal pressure during gas discharge is 190.6 kPa, the minimum value is 163.4 kPa, the average value is 174.6 kPa, and the pressure difference is 27.2 kPa. It was.

  As described above, it was found that in the electricity storage device 1 according to the present embodiment, the internal pressure during gas discharge can be significantly reduced as compared with Comparative Examples 1 and 2. In particular, the internal pressure during gas discharge according to the present embodiment was less than half of the internal pressure during gas discharge according to Comparative Example 2. Further, it was found that the gas discharge internal pressure according to the present embodiment is lower than the gas discharge internal pressure according to Comparative Example 1. Therefore, in the electricity storage device 1 according to the present embodiment, it is understood that even when the shortest adhesion width W0 is set longer than that in the case of the comparative example 1, an internal pressure at the time of gas discharge equivalent to that in the comparative example 1 can be obtained. It was. That is, in the electricity storage device 1 according to the present embodiment, by setting the shortest adhesion width W0 longer than in the case of Comparative Example 1, even if the sealing performance of the inner region S1 of the stacked body storage unit 121 is increased, An excessive increase in internal pressure during gas release can be suppressed. Furthermore, it was also found that in the electricity storage device 1 according to the present embodiment, the pressure difference of the internal pressure during gas discharge was smaller than that in Comparative Example 1. Therefore, the power storage device 1 according to the present embodiment has an advantage that the design of the power storage device 1 can be facilitated because the margin for variation in the internal pressure during gas discharge can be reduced compared to the first comparative example.

Next, a method for manufacturing the electricity storage device 1 will be described.
First, the laminated body 119 is surrounded by the film members 125a and 125b from both sides of the laminated body 119, and the overlapping portions 122a and 122b of the film member 125a and the film member 125b are provided on the periphery of the film members 125a and 125b. . And the 1st adhesion part 123, the 2nd adhesion part 123a, and the non-adhesion part 124 are formed by performing heat fusion processing to overlap parts 122a and 122b.

FIG. 3B to FIG. 3D show cross-sectional views in each step of the method for manufacturing the electricity storage device 1. Here, a case will be described in which the heat-sealing process is performed with the spacers 14 interposed between the overlapping portions 122a and 122b.
The spacers 14 are arranged between portions corresponding to a plurality of (two in FIG. 3B) second adhesive portions 123a in the overlapping portions 122a and 122b (non-adhesive portion forming regions 126a and 126b). As shown in FIG. 3B, the spacer 14 is in a state of being interposed in the non-adhesive portion forming regions 126a and 126b in the overlapping portions 122a and 122b. The spacer 14 may be interposed between the overlapping portions 122a and 122b by overlapping the film members 125a and 125b in a state where the spacer 14 is placed on one of the film members 125a and 125b.

  Next, a heat-bonding process is performed on the overlapping portions 122a and 122b, thereby forming a stacked body storage portion 121 that stores the stacked body 119, a first bonding portion 123, and a non-bonding portion 124. Specifically, as shown in FIG. 3C, the overlapping portions 122a and 122b are sandwiched by the heat fusion head H while applying heat from both sides in the overlapping direction of the overlapping portions 122a and 122b (FIG. 3C). (Refer to the arrow in the figure.) Apply heat fusion treatment. If it does so, area | regions other than the non-bonding part scheduled area | regions 126a and 126b in which the spacer 14 is arrange | positioned in the overlapping parts 122a and 122b will be heat-seal | fused.

  Thereafter, the through hole 16 penetrating the second adhesive portion 123 a is formed in the second adhesive portion 123 a of the first adhesive portion 123. For example, as shown in FIG. 3 (d), the through-hole 16 is drilled in the second adhesive portion 123a using the punching machine P.

  As described above, the power storage device 1 according to the present embodiment has the two second adhesive portions 123a and the through holes 16 provided in them. As a result, even if the shortest distance (shortest adhesion width) between the inner side (region S1) of the multilayer body storage unit 121 and the through-hole 16 is set to a length necessary to prevent intrusion of moisture and the like from the outside, gas release An excessive rise in internal pressure can be suppressed. Therefore, it is possible to prevent the exterior member 12 from being ruptured while enhancing the sealing performance inside the laminate housing portion 121 of the exterior member 12, so that the safety of the electricity storage device 1 can be enhanced. And since the penetration | invasion of the water | moisture content etc. to the inner side of the laminated body storage part 121 can be suppressed by improving the sealing performance inside the laminated body storage part 121, the performance maintenance of the electrical storage device 1 can be aimed at.

  Moreover, the electrical storage device 1 according to the present embodiment has two second adhesive portions 123a. Thereby, for example, due to manufacturing variation, the bonding strength of one of the two second bonding portions 123a becomes extremely strong, and even if the gas cannot be released even if the internal pressure at the time of gas discharge is reached, the other second bonding is performed. Gas can be released from the portion 123a.

When the internal pressure of the exterior member 12 increases, the peeling stress applied to the first adhesive portion 123 is greater on the long side than on the short side of the exterior member 12.
On the other hand, in the present embodiment, the second bonding portion 123 a is provided along the long side of the exterior member 12. As a result, the degree of peeling at the second adhesive portion 123a can be increased. Therefore, when trying to set a certain gas discharge pressure, the second adhesive portion is provided along the short side of the exterior member 12. And the shortest distance from the inner side of the laminated body storage part 121 of the through-hole 16 can be shortened. Therefore, the sealing performance of the exterior member 12 can be improved.

  According to the method for manufacturing the electricity storage device 1 according to the present embodiment, the through-hole 16 is formed after the overlapping portions 122a and 122b of the film members 125a and 125b are heat-sealed by performing heat-sealing treatment. To do. Thereby, the through-hole provided in each film member 125a, 125b can be made to correspond in planar view. In addition, since the through-hole 16 is formed after the heat-sealing process is performed, it is possible to prevent the occurrence of a problem that a part of the resin constituting the heat-fusible resin layer of the film members 125a and 125b protrudes into the through-hole 16 There is an advantage that you can.

(Embodiment 2)
As shown in FIG. 6, the power storage device 201 according to the present embodiment includes four second adhesive portions 223a and 223b and through holes 216a and 216b formed in the second adhesive portions 223a and 223b. . In FIG. 6, among the four second adhesive portions, the one closer to the center in the longitudinal direction of the exterior member 12 in plan view (the one far from the corner) is 223 a, and the one far from the center (the one far from the corner) is 223 b. It is said. In addition, the laminated body storage unit 121 has a rectangular shape in plan view as in the first embodiment. The centers of the through holes 216a and 216b are located on a virtual straight line KL extending in the longitudinal direction of the exterior member 12.

  In the electricity storage device 201, the gas release internal pressure differs between the second adhesive portion 223a and the second adhesive portion 223b. Specifically, the internal pressure at the time of gas release at the second adhesive portion 223a is lower than the internal pressure at the time of gas release at the second adhesive portion 223b. Therefore, when the pressure inside the exterior member 12 rises, when the gas is not released from the through-hole 216a formed in the second adhesive portion 223a due to a manufacturing defect or the like, the second adhesive portion 223b is provided. Gas is released from the formed through-hole 216b.

  By the way, as can be seen from the evaluation result of the gas release performance described in the first embodiment, the internal pressure at the time of gas discharge decreases with the increase in the number of the second adhesive portions and the through holes. In addition, the variation in the internal pressure during gas discharge is also reduced as the number of second adhesive portions and through holes is increased.

  The power storage device 201 according to the present embodiment has a larger number of second adhesive portions 223a and 223b and through holes 216a and 216b than the power storage device 1 of the first embodiment. Thereby, when setting the internal pressure at the time of gas discharge | release of the exterior member 12 to a certain specific pressure, compared with the electrical storage device 1 of Embodiment 1, the shortest adhesion width | variety can be set long. Therefore, the electricity storage device 201 can improve the sealing performance inside the exterior member 12 as compared to the electricity storage device 1 according to Embodiment 1. Furthermore, fluctuations in the internal pressure during gas discharge can be reduced.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments.

  In the first and second embodiments, the configuration in which the second adhesive portions 123, 223a, and 223b in which the through holes 16, 216a, and 216b are formed has two and four is described. However, the through holes are formed in the first and second embodiments. The number of second adhesive portions is not limited to these. For example, the structure which has the 2nd adhesion part by which the 3 or 5 or more through-hole was pierced may be sufficient.

  In particular, when there are five or more second adhesive portions having through holes, the greater the number of second adhesive portions having through holes, the higher the reliability of gas emission. The gas is released from the through-hole if there is at least one normal second adhesive portion. Accordingly, the greater the number of second adhesive portions, the greater the allowable number of second adhesive portions that are not capable of releasing gas, thereby increasing the certainty of gas release.

  In the embodiment, the example has been described in which the non-bonding portion 124 has a substantially rectangular shape in plan view, and the second bonding portion 123a is provided between the non-bonding portions 124. However, the shape of the non-bonding portion 124 is limited to this. It is not something. For example, as in the power storage device 401 illustrated in FIG. 7, a configuration in which four island-shaped second adhesive portions 423 are provided and through holes 416 are formed in each of the second adhesive portions 423 may be employed. The power storage device 401 includes a non-adhesive portion 424 provided to surround the second adhesive portion 423 in plan view.

  In the first embodiment, the example in which the non-bonding portion 124 and the second bonding portion 123a are provided along one side of the exterior member 12 has been described. However, the portion where the non-bonding portion 124 and the second bonding portion 123a are provided is as follows. It is not limited to a portion along one side of the exterior member 12.

  For example, as shown in FIG. 8, the exterior member 12 has a rectangular shape in plan view, and three non-bonding portions 524 are provided along two opposing long sides, and the second of the bonding portion 523 is provided. The power storage device 501 provided with two bonding portions 523a along two opposing long sides may be used.

  According to this configuration, the gas filled in the exterior member 12 can be released to the outside from the portions along the two opposing sides of the exterior member 12, so that the gas inside the exterior member 12 can be efficiently discharged to the outside. Can be released. In addition, the fluctuation in the internal pressure during gas discharge can be reduced.

  In the first embodiment, the example in which the first adhesive portion 123 is formed over the entire outer periphery of the stacked body storage portion 121 when the exterior member 12 is viewed in plan is described. It is not limited to. For example, as shown in FIG. 9, when the exterior member 612 of the power storage device 601 is viewed in plan, the adhesive portion 623 is formed only on the outer periphery along the three sides of the rectangular laminate housing portion 621. There may be. The exterior member 612 is formed by, for example, heat-sealing the peripheral portions along the three sides with the laminated body 119 sandwiched from both sides in the laminating direction by one film member folded in two. In the exterior member 612, for example, the non-adhesive portion 624 and the second adhesive portion 623a of the adhesive portion 623 face one side where the adhesive portion 623 is not provided in the stacked body storage portion 621 when the exterior member 612 is viewed in plan. Provided on the side.

In Embodiment 1, the width L4 of the first adhesive portion 123 on one side where the second adhesive portion 123a of the exterior member 12 having a rectangular shape in plan view is provided is equal to the width L4 of the first adhesive portion 123 on each other side of the exterior member 12. An example narrower than the width L3 has been described. However, the setting of the width | variety of the 1st adhesion part 123 in each edge | side of the exterior member 12 is not limited to this.
For example, as shown in FIG. 10, the width of the first bonding portion 123 on each side of the exterior member 712 may be set to the same width L3. In this case, what is necessary is just to set it as the structure by which the 2nd adhesion part 723a is provided in the hollow part 721c dented inside the laminated body storage part 721.

  In Embodiment 1, the example in which the second bonding portion 123a is rectangular in plan view has been described, but the shape of the second bonding portion 123a is not limited to this. For example, it may have a shape of a triangular shape in plan view and may be connected to a portion other than the non-bonded portion in the bonded portion on one side.

  In Embodiment 1, the example in which the spacer 14 is formed of polyimide has been described, but the material of the spacer 14 is not limited to this. For example, the spacer 14 may be formed from a heat resistant sheet such as polyamide, cellulose, PTFE (polytetrafluoroethylene), or the like.

  In each embodiment, although the example provided with the spacer 14 was demonstrated, the structure without the spacer 14 may be sufficient.

  In the embodiment described above, the power storage device 1 is a dual carbon battery, but the type of power storage device is not limited to this. For example, various secondary batteries such as a lithium ion battery, an electric double layer capacitor, and a lithium ion capacitor may be used.

1, 501, 601 Power storage device 12, 612 Exterior member 14, 214 Spacer 16, 216a, 216b, 316a, 316b, 416a, 416b Through hole 111 External terminal for positive electrode 112 External terminal for negative electrode 113 Positive electrode 114 Negative electrode 116 Separator 117a, 118a Extraction electrode portion 117b, 118b Joint portion 119 Laminated body 121, 621 Laminated body storage portion 122, 622 Outer peripheral portion 122a, 122b Overlap portion 123 Adhesive portion 123a, 223a, 223b, 323a, 323b, 423a, 423b, 523a, 623a Second Adhesion part 124, 224, 324, 424, 524, 624 Non-adhesion part 125a, 125b Film member H Thermal fusion head P Punching machine S1 area

Claims (4)

A first adhesive portion formed by adhering at least the entire outer edge of the overlapping portion of the film member formed on the periphery of the film member, and sealed by the film member and the first adhesive portion. An exterior member having a region;
A battery element housed in a region sealed by the first adhesive portion, and an electricity storage device comprising:
The exterior member is
A plurality of second adhesive portions formed by adhering the overlapping portions disposed on the battery element side along a boundary between the region sealed by the first adhesive portions and the first adhesive portion; ,
The plurality of second adhesive portions each have a through-hole having a size penetrating the second adhesive portion and leaving a region adhered to the periphery.
Power storage device. The region sealed by the first adhesive portion has a rectangular shape in plan view,
The plurality of second adhesive portions are disposed along the battery element side of the boundary between the long side of the region sealed by the first adhesive portion and the first adhesive portion.
The electricity storage device according to claim 1. An overlapping part forming step of surrounding the battery element from both sides sandwiching the battery element with a film member and providing an overlapping part on a peripheral part of the film member;
A region where the battery element is arranged is formed by adhering at least the entire edge of the overlapping portion opposite to the battery element side to form a first adhesive portion, and the first adhesive portion Forming a plurality of second adhesive portions arranged on the battery element side along a boundary between the battery element and the region where the battery element is arranged;
A through-hole drilling step for drilling a through-hole having a size that penetrates the second adhesive portion and leaves a region adhered to the periphery.
A method for manufacturing an electricity storage device. The overlapping portion forming step further includes a step of interposing a spacer in a portion corresponding to at least between the plurality of second adhesive portions in the overlapping portion,
In the bonding part forming step, the overlapping part is heat-sealed.
The manufacturing method of the electrical storage device of Claim 3.