Power storage module

Abstract

To provide a power storage module that easily keeps an electrolyte solution permeated into a lamination electrode body within the lamination electrode body.SOLUTION: A power storage module includes a lamination electrode body in which a plurality of electrodes are stacked in a first direction and an electrolyte solution permeates, and an accommodation body that accommodates the lamination electrode body. The accommodation body and the lamination electrode body extend in a second direction that is perpendicular to the first direction. The power storage module further includes a plate-shaped member that extends in the second direction and is disposed facing the lamination electrode body in the accommodation body. The plate-shaped member is disposed so that a third direction perpendicular to the first direction and the second direction corresponds to a thickness direction of the plate-shaped member. The plate-shaped member includes a counter surface facing the lamination electrode body. At least a part of the counter surface is bent or curved along the second direction. By the bending or curving of the counter surface, a space is formed between the counter surface and the lamination electrode body.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to an energy storage module. [Background technology]

[0002] Conventionally, energy storage modules including laminated structures serving as electrode bodies have been known. Japanese Patent Laid-Open Publication No. 2002-198099 (Patent Document 1) discloses, as such an energy storage module, a sheet-like lithium secondary battery in which a power generating element is a laminated structure including a plurality of units in which a positive sheet electrode and a negative sheet electrode are stacked with a separator or a solid electrolyte layer interposed therebetween, and tape is wrapped around the outer periphery of the laminated structure to bind and fix the plurality of sheet electrodes constituting the laminated structure with the tape. In this sheet-like lithium secondary battery, a plurality of through-holes are distributed in the tape covering the side surface of the laminated structure so that the laminated structure can be impregnated with the electrolyte in a short time during the process of impregnating the laminated structure with the electrolyte during battery manufacturing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-198099 Summary of the Invention [Problem to be solved by the invention]

[0004] In an electricity storage module, in order to maintain the performance of the battery, it is necessary to retain the electrolyte impregnated in the laminated electrode body within the laminated electrode body. The sheet-shaped lithium secondary battery of Patent Document 1 cannot be said to have a high performance (liquid retention performance) for retaining the electrolyte impregnated in the laminated electrode body (laminated structure) within the laminated electrode body. Therefore, an improvement in the liquid retention performance is desired.

[0005] The present disclosure provides an electricity storage module that makes it easy to retain an electrolyte solution impregnated in a laminated electrode body within the laminated electrode body. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, the energy storage module includes a stacked electrode assembly in which a plurality of electrodes are stacked in a first direction and impregnated with an electrolyte solution, and a housing that houses the stacked electrode assembly. The housing and the stacked electrode assembly extend in a second direction perpendicular to the first direction. The energy storage module further includes a plate-shaped member that extends in the second direction and is arranged in the housing so as to face the stacked electrode assembly. The plate-shaped member is arranged such that a third direction perpendicular to the first and second directions corresponds to the thickness direction of the plate-shaped member. The plate-shaped member has an opposing surface that faces the stacked electrode assembly. At least a portion of the opposing surface is bent or curved along the second direction. The bending or curving of the opposing surface forms a space between the opposing surface and the stacked electrode assembly.

[0007] With this configuration, the electrolyte can be held in the space formed between the opposing surface and the laminated electrode body, making it easier to supply the electrolyte to the laminated electrode body. Therefore, compared to a configuration without a plate-shaped member, the electrolyte impregnated in the laminated electrode body can be more easily held within the laminated electrode body.

[0008] Preferably, the plate-like member has a central portion and both end portions in the second direction, and the central portion is thinner than the both end portions.

[0009] Generally, the center of the laminated electrode body in the second direction tends to retain electrolyte less easily than the ends in the D2 direction. This makes it easier for the electrolyte to migrate from the center of the laminated electrode body in the second direction to the periphery of the center. Therefore, by making the center of the plate-like member thinner than the ends, as in the above configuration, it becomes easier to supply the electrolyte to the center of the laminated electrode body in the second direction. This improves the electrolyte retention performance of the center of the laminated electrode body in the second direction.

[0010] Preferably, the plate-like member has a plurality of through holes formed at different positions in the second direction, each of which penetrates in the third direction. This configuration makes it easier to supply the electrolyte solution to the laminated electrode body during injection, compared to a configuration without through holes. Furthermore, since the electrolyte solution remains in the through holes even after injection, it is easier to supply the electrolyte solution to the laminated electrode body. This improves the electrolyte retention performance of the laminated electrode body.

[0011] Preferably, the opening area of ​​a first through hole among the plurality of through holes that is closer to the center than one of the ends of both ends is larger than the opening area of ​​a second through hole among the plurality of through holes that is closer to one end than the center.

[0012] This configuration makes it easier to supply the electrolyte to the center of the laminated electrode body in the second direction during injection. Furthermore, since the electrolyte remains in the through-holes even after injection, the electrolyte retention performance in the center of the laminated electrode body in the second direction can be improved. [Effects of the Invention]

[0013] According to the present disclosure, the electrolyte impregnated in the laminated electrode body can be easily retained within the laminated electrode body. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 2 is a perspective view of the storage module. [Figure 2] 2 is a diagram showing a stacked electrode body included in the electricity storage module of FIG. 1. FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along the line III-III in FIG. [Figure 4] 4 is a view of the plate-like member as viewed in the direction of arrow IV shown in FIG. 3. [Figure 5] 5 is a view of the plate-shaped member in the state of FIG. 4 as viewed from above. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the embodiments described below, the same or common parts are denoted by the same reference numerals in the drawings, and the description thereof will not be repeated.

[0016] FIG. 1 is a perspective view of an energy storage module according to the present embodiment. FIG. 2 is a diagram showing a laminated electrode body included in the energy storage module of FIG. 1. As shown in FIGS. 1 and 2, the energy storage module 1 has a blade shape. The energy storage module 1 includes a laminated electrode body 100 and a housing body 2 that houses the laminated electrode body 100. For ease of explanation, the energy storage module 1 will be described below using as an example a case in which the energy storage module 1 is oriented such that the D3 direction shown in FIGS. 1 and 2 is vertical (more specifically, the direction of D31, which will be described later, faces vertically upward) except during injection of an electrolyte solution, which will be described later.

[0017] In this example, the energy storage module 1 is a lithium iron phosphate (LFP) battery. However, the energy storage module 1 is not limited to this, and may be a ternary (NMC) battery. The energy storage module 1 is mounted, for example, on an electric vehicle that runs on driving force obtained from electric energy. More specifically, a battery pack including a plurality of energy storage modules 1 arranged in a predetermined direction is mounted on the electric vehicle. The battery pack is attached to the body of the electric vehicle. The battery pack forms part of the body. The battery pack serves as a structural component of the body.

[0018] As shown in FIG. 1 , the housing 2 has a substantially rectangular parallelepiped shape. In this example, the housing 2 is a metal housing. The housing 2 has first to sixth surfaces 21 to 26. The first surface 21, the second surface 22, the third surface 23, and the fourth surface 24 are continuous in this order. The first surface 21, the second surface 22, the third surface 23, and the fourth surface 24 form the outer peripheral surface of the housing 2.

[0019] The fifth surface 25 and the sixth surface 26 are end surfaces of the housing body 2. The first surface 21 is the top surface, the second surface 22 is the bottom surface, and the third surface 23 and the fourth surface 24 are side surfaces. A negative electrode side external connection terminal 27 is provided on the fifth surface 25. A positive electrode side external connection terminal (not shown) is provided on the sixth surface 26.

[0020] The D1 direction is the width direction of the energy storage module 1. As shown in FIG. 2, the laminated electrode body 100 has multiple electrodes stacked in the D1 direction (stacking direction). More specifically, in the laminated electrode body 100, a negative electrode 110 and a positive electrode 120 are stacked in the D1 direction with a separator 130 interposed between them. The laminated electrode body 100 further includes a tab 150 connected to the negative electrode side external connection terminal 27, and a tab 160 connected to the positive electrode side external connection terminal. The tab 150 is made of a copper foil. The tab 160 is made of an aluminum foil.

[0021] As shown in FIG. 1, the energy storage module 1 and the housing body 2 extend in the D2 direction. As shown in FIG. 2, the stacked electrode body 100 has a substantially rectangular parallelepiped shape. The stacked electrode body 100 extends in the D2 direction. The D2 direction is perpendicular to the D1 direction. The D2 direction is the longitudinal direction of the energy storage module 1, the housing body 2, and the stacked electrode body 100. The D3 direction is perpendicular to the D1 and D2 directions. The D3 direction is the height direction of the energy storage module 1.

[0022] The D1 direction is the short-side direction of each of the first surface 21, the second surface 22, the fifth surface 25, and the sixth surface 26. The D2 direction is the long-side direction of the first to fourth surfaces 21 to 24. The D3 direction is the short-side direction of the third and fourth surfaces 23 and 24, and the long-side direction of the fifth and sixth surfaces 25 and 26.

[0023] A liquid inlet 2h for injecting the electrolyte into the container 2 is formed on the fifth surface 25. The liquid inlet 2h is formed closer to the first surface 21 than the second surface 22 of the container 2. The liquid inlet 2h is formed closer to the first surface 21 than the external connection terminal 27. In the state shown in FIG. 1, the liquid inlet 2h is blocked because the electrolyte has already been injected into the container 2. The liquid inlet 2h may be temporarily blocked by inserting a removable plug into the liquid inlet 2h. Alternatively, the liquid inlet 2h may be blocked with resin or metal, so that the electrolyte cannot be reinjected unless a through-hole is opened.

[0024] When injecting the electrolyte solution through the injection hole 2h during manufacturing of the electricity storage module 1, the attitude of the electricity storage module 1 is maintained so that the D2 direction is substantially vertical and the fifth surface 25 is higher than the sixth surface 26. The electrolyte solution flows from the fifth surface 25 side to the sixth surface 26 side due to its own weight. Note that the electrolyte solution has a certain degree of viscosity, and therefore falls within the container 2 at a relatively slow speed. This allows the stacked electrode body 100 to be impregnated with the electrolyte solution.

[0025] In this example, the liquid inlet 2h is formed closer to the first surface 21 than the external connection terminal 27, but is not limited to this. The liquid inlet 2h may be formed closer to the second surface 22 than the external connection terminal 27. The liquid inlet 2h may be formed closer to the third surface 23 than the external connection terminal 27. The liquid inlet 2h may be formed closer to the fourth surface 24 than the external connection terminal 27.

[0026] Furthermore, in this example, the configuration in which the liquid inlet 2h is formed on the fifth surface 25 has been described as an example, but the present invention is not limited to this. For example, the liquid inlet 2h may be formed on the sixth surface 26. The liquid inlet 2h may be formed on the first surface 21 or the second surface 22. When the liquid inlet 2h is formed on the first surface 21 or the second surface 22, from the viewpoint of liquid inlet performance, it is preferable that the liquid inlet 2h be formed closer to the end portion (the fifth surface 25 side or the sixth surface 26 side) than to the center in the longitudinal direction of the container 2. The liquid inlet 2h may be formed on the third surface 23 or the fourth surface 24. The position in which the liquid inlet 2h is formed is not particularly limited.

[0027] As described above, the energy storage module 1 has a blade shape. Therefore, the housing 2 also has a blade shape. The stacked electrode assembly 100 housed in the housing 2 also has a blade shape. Therefore, the length in the D3 direction of the housing 2, the negative electrode 110, and the positive electrode 120 is longer than the length in the D1 direction of the housing 2, the negative electrode 110, and the positive electrode 120. Furthermore, the length in the D2 direction of the housing 2, the negative electrode 110, and the positive electrode 120 is longer than the length in the D3 direction of the housing 2, the negative electrode 110, and the positive electrode 120.

[0028] As an example, the length of the housing body 2 in the D3 direction is 6 to 7 times the length of the housing body 2 in the D1 direction. As an example, the length of the housing body 2 in the D2 direction is 10 to 11 times the length of the housing body 2 in the D3 direction. However, the ratio between the length of the housing body 2 in the D1 direction, the length of the housing body 2 in the D2 direction, and the length of the housing body 2 in the D3 direction is not limited to this.

[0029] Fig. 3 is a cross-sectional view taken along the line III-III in Fig. 1. As shown in Fig. 3, the energy storage module 1 further includes plate-like members 201 and 202, tape materials 301 and 302, and an insulating sheet 500 in addition to the housing 2 and the stacked electrode assembly 100.

[0030] The plate-shaped members 201 and 202, the tape materials 301 and 302, and the insulating sheet 500 are housed in the housing 2, similar to the laminated electrode body 100. The plate-shaped members 201 and 202, the tape materials 301 and 302, and the insulating sheet 500 are disposed between the laminated electrode body 100 and the housing 2 (in the gap).

[0031] The plate-shaped members 201 and 202 are insulators. In this example, the plate-shaped members 201 and 202 are made of resin. In this example, the plate-shaped members 201 and 202 are made of an insulating material from the viewpoint of preventing a short circuit between the positive electrode 120 and the negative electrode 110 in the laminated electrode body 100. Note that, if a sufficient insulation distance is ensured between the plate-shaped members 201 and 202 and the laminated electrode body 100, the plate-shaped members 201 and 202 do not necessarily need to be insulators.

[0032] For example, polypropylene is used as the material for forming the plate-like members 201 and 202. However, without being limited to this, polyethylene, polyphenylene sulfide, polyether ether ketone, PET (polyethylene terephthalate), or the like may also be used.

[0033] The plate-shaped member 201 is disposed in the housing 2 so as to face the stacked electrode body 100. The plate-shaped member 201 is disposed on the stacked electrode body 100. More specifically, the plate-shaped member 201 is disposed directly above the stacked electrode body 100. The plate-shaped member 201 is disposed on the first surface 21 side of the housing 2. The plate-shaped member 201 is disposed in the direction D31 of the D3 direction relative to the stacked electrode body 100. As described above, the direction D31 is vertically upward.

[0034] Similar to the plate-shaped member 201, the plate-shaped member 202 is disposed in the housing 2 so as to face the stacked electrode body 100. The plate-shaped member 202 is disposed below the stacked electrode body 100. More specifically, the plate-shaped member 202 is disposed directly below the stacked electrode body 100. The plate-shaped member 202 is installed on the second surface 22 side of the housing 2. The plate-shaped member 202 is installed in a direction D32 of the D3 direction relative to the stacked electrode body 100. The direction D32 is vertically downward.

[0035] Fig. 4 is a view of the plate-shaped members 201 and 202 as viewed in the direction of arrow IV shown in Fig. 3. Fig. 4 is a side view of the plate-shaped members 201 and 202. As shown in Fig. 4, the plate-shaped members 201 and 202 extend in the direction D2. The plate-shaped members 201 and 202 are arranged in the housing 2 so that the direction D3 is the thickness direction of the plate-shaped member 201.

[0036] The plate-like member 201 has a central portion C1 in the D2 direction and both end portions E11 and E12 in the D2 direction. The end portion E11 is the end portion on the external connection terminal 27 side shown in FIG. 1. The end portion E12 is the end portion opposite the end portion E11. The central portion C1 and both end portions E11 and E12 have different thicknesses. In the example of FIG. 4, the central portion C1 is thinner than both end portions E11 and E12.

[0037] The plate-shaped member 201 further has first to sixth surfaces 211 to 216. The first surface 211 is the surface on the first surface 21 side of the housing 2. The first surface 211 is the surface opposite to the laminated electrode body 100. In this example, the first surface 211 is a flat surface. In the states of FIGS. 3 and 4, the first surface 211 is the top surface. The first surface 211 is parallel to the laminated electrode body 100.

[0038] The second surface 212 is the surface facing the laminated electrode body 100. In the state shown in FIGS. 3 and 4, the second surface 212 is the bottom surface. The second surface 212 is the surface facing the laminated electrode body 100. The second surface 212 is bent along the D2 direction. In this example, the second surface 212 is bent at the center portion C1. The second surface 212 is recessed in the direction D31. Specifically, in this example, the second surface 212 includes an inclined surface 212a and an inclined surface 212b. More specifically, the second surface 212 includes a region along the D2 direction where the separation distance between the second surface 212 and the laminated electrode body 100 is equal to or less than a reference value (length) along the D1 direction, and a region where the separation distance is longer than the reference value along the D1 direction.

[0039] In this example, the inclined surfaces 212a and 212b are flat surfaces. The inclined surfaces 212a and 212b are inclined along the direction D2. The inclined surfaces 212a and 212b are each inclined so that the thickness of the central portion C1 of the plate-shaped member 201 is thinner than the thicknesses of both end portions E11 and E12. As a result, a space S1 in which an electrolyte solution is stored is formed between the inclined surfaces 212a and 212b and the stacked electrode body 100.

[0040] As described above, the first surface 211 is parallel to the laminated electrode body 100, and therefore the inclined surfaces 212a and 212b cause the thickness of the plate-shaped member 201 to gradually decrease toward the central portion C1. The inclined surfaces 212a and 212b provide the plate-shaped member 201 with portions that are thicker than a predetermined thickness and portions that are equal to or smaller than the predetermined thickness.

[0041] The third surface 213 is the surface on the third surface 23 side of the housing body 2. The fourth surface 214 is the surface on the fourth surface 24 side of the housing body 2. The third surface 213 and the fourth surface 214 are side surfaces of the plate-shaped member 201. The fifth surface 215 is the end surface on the end E11 side. The sixth surface 216 is the end surface on the end E12 side.

[0042] The plate-like member 202 has a central portion C2 in the D2 direction and both end portions E21, E22 in the D2 direction. The end portion E21 is the end portion on the external connection terminal 27 side shown in FIG. 1. The end portion E22 is the end portion opposite the end portion E11. The central portion C2 and both end portions E21, E22 have different thicknesses. In the example of FIG. 4, the central portion C2 is thinner than both end portions E21, E22.

[0043] The plate-shaped member 202 further has first to sixth surfaces 221 to 226. The first surface 221 is the surface on the second surface 22 side of the housing 2. The first surface 221 is the surface opposite to the stacked electrode body 100. In this example, the first surface 221 is a flat surface. In the states of FIGS. 3 and 4, the first surface 221 is the bottom surface. The first surface 221 is parallel to the stacked electrode body 100.

[0044] The second surface 222 is the surface facing the laminated electrode body 100. In the states of FIGS. 3 and 4, the second surface 222 is the top surface. The second surface 222 is the surface facing the laminated electrode body 100. The second surface 222 is bent along the D2 direction. In this example, the second surface 212 is bent at the center portion C1. The second surface 222 is recessed in the direction D32. Specifically, in this example, the second surface 222 includes an inclined surface 222a and an inclined surface 222b. More specifically, like the second surface 212 of the plate-shaped member 201, the second surface 222 includes, along the D2 direction, a region where the distance between the second surface 222 and the laminated electrode body 100 is equal to or less than a reference value across the D1 direction, and a region where the distance is longer than the reference value.

[0045] In this example, the inclined surfaces 222a and 222b are flat surfaces. The inclined surfaces 222a and 222b are inclined along the direction D2. The inclined surfaces 222a and 222b are each inclined so that the thickness of the central portion C2 of the plate-shaped member 202 is thinner than the thickness of both end portions E21 and E22. As a result, a space S2 in which an electrolyte solution is stored is formed between the inclined surfaces 222a and 222b and the stacked electrode body 100.

[0046] As described above, the first surface 221 is parallel to the laminated electrode body 100, and therefore the inclined surfaces 222a and 222b cause the thickness of the plate-shaped member 202 to gradually decrease toward the center C2. The inclined surfaces 222a and 222b cause the plate-shaped member 202 to have portions where the thickness is thicker than a reference thickness and portions where the thickness is equal to or less than the reference thickness.

[0047] The third surface 223 is the surface on the third surface 23 side of the housing body 2. The fourth surface 224 is the surface on the fourth surface 24 side of the housing body 2. The third surface 223 and the fourth surface 224 are side surfaces of the plate-shaped member 202. The fifth surface 225 is the end surface on the end E21 side. The sixth surface 226 is the end surface on the end E22 side.

[0048] In this example, the plate-shaped member 202 has a shape symmetrical to the plate-shaped member 201 with respect to the laminated electrode assembly 100. However, the present invention is not limited to this.

[0049] As shown in FIG. 3 , the plate-shaped member 201 is fixed to the laminated electrode body 100 by a tape material 301. The tape material 301 extends in the D2 direction. The tape material 301 covers all or part of the first surface 211 of the plate-shaped member 201. The tape material 301 covers all or part of the third and fourth surfaces 213, 214 of the plate-shaped member 201. The tape material 301 covers a portion of the laminated electrode body 100.

[0050] The plate-shaped member 202 is fixed to the laminated electrode body 100 by a tape material 302. The tape material 302 extends in the D2 direction. The tape material 302 covers all or part of the first surface 221 of the plate-shaped member 202. The tape material 302 covers all or part of the third and fourth surfaces 223, 224 of the plate-shaped member 202. The tape material 302 covers a portion of the laminated electrode body 100.

[0051] The insulating sheet 500 insulates the laminated electrode body 100 from the housing 2. The insulating sheet 500 covers the laminated electrode body 100 so that the laminated electrode body 100 does not come into contact with the housing 2. The insulating sheet 500 is provided between the laminated electrode body 100 and the housing 2 (more specifically, the inner surface of the housing) to prevent a short circuit of the laminated electrode body 100.

[0052] More specifically, the insulating sheet 500 covers the plate-shaped members 201 and 202. The insulating sheet 500 covers the plate-shaped member 201 via the tape material 301. Similarly, the insulating sheet 500 covers the plate-shaped member 202 via the tape material 302.

[0053] The insulating sheet 500 has both ends welded together. With the plate-shaped members 201, 202 fixed to the laminated electrode assembly 100 by the tape materials 301, 302, the insulating sheet 500 is wrapped around the tape materials 301, 302, the plate-shaped members 201, 202, and the laminated electrode assembly 100. Then, both ends of the insulating sheet 500 are welded together to obtain the insulating sheet 500 shown in FIG. 3. In the welded region T, the ends of the insulating sheet 500 overlap. The welded region T extends in the D2 direction. The insulating sheet 500 may also be formed by connecting multiple insulating sheets.

[0054] For example, polypropylene is used as the material for insulating sheet 500. However, without being limited to this, polyethylene, polyphenylene sulfide, polyether ether ketone, nylon, or PET (polyethylene terephthalate) may also be used.

[0055] Fig. 5 is a view of the plate-shaped member 201 of Fig. 4 as viewed in the direction of arrow V. Fig. 5 is a view of the plate-shaped member 201 as viewed from above in the state of Fig. 4.

[0056] 5, the plate-shaped member 201 has a plurality of through holes 290 formed at different positions in the D2 direction, each of which penetrates in the D3 direction. Specifically, the plate-shaped member 201 has a plurality of through holes 290 formed from the first surface 211 toward the second surface 212, which is the back surface of the first surface 211. The plurality of through holes 290 are aligned in a line in the D2 direction. However, this is not limiting, and the plurality of through holes 290 may be aligned in multiple rows in the D2 direction.

[0057] In this example, the opening area of ​​the through-holes 290 closer to the center C1 than the end E11 (or end E12) is larger than the opening area of ​​the through-holes 290 closer to the end E11 (or end E12) than the center C1. Specifically, the opening area of ​​the through-holes 290 increases from the end ends E11, E12 toward the center C1. This is to make it easier to supply the electrolyte to the center of the laminated electrode body 100 in the D2 direction. However, this is not limited to this, and the opening area of ​​each through-hole 290 may be the same.

[0058] The distance between each of the through holes 290 may be constant or may vary. When the opening area of ​​each of the through holes 290 is the same, it is preferable to form more of the through holes 290 closer to the center C1 than to the end ends E11, E12, from the viewpoint of facilitating the supply of electrolyte to the center of the laminated electrode body 100 in the D2 direction.

[0059] Similar to the plate-shaped member 201, the plate-shaped member 202 also has a plurality of through holes 290. In this example, the plate-shaped member 202 has the same configuration as the plate-shaped member 201, and therefore, description of each of the through holes 290 of the plate-shaped member 202 will not be repeated here.

[0060] <Summary> (1) As shown in Figures 1 and 2, the energy storage module 1 includes a laminated electrode assembly 100 in which multiple electrodes are stacked in the D1 direction and impregnated with an electrolyte solution, and a housing 2 that houses the laminated electrode assembly 100. The housing 2 and the laminated electrode assembly 100 extend in a D2 direction that is perpendicular to the D1 direction. As shown in Figures 3 and 4, the energy storage module 1 further includes plate-like members 201 and 202 that extend in the D2 direction and are arranged in the housing 2 so as to face the laminated electrode assembly 100.

[0061] The plate-shaped members 201, 202 are arranged such that the D3 direction, which is perpendicular to the D1 and D2 directions, corresponds to the thickness direction of the plate-shaped members 201, 202. As shown in Fig. 4, the plate-shaped members 201, 202 have second surfaces 212, 222 that face the laminated electrode body 100. The second surfaces 212, 222 are bent along the D2 direction. Due to the bending of the second surfaces 212, 222, spaces S1, S2 are formed between the second surfaces 212, 222 and the laminated electrode body 100.

[0062] With this configuration, the electrolyte can be held in the spaces S1, S2 (gaps) between the second surfaces 212, 222 and the stacked electrode body 100. This makes it easier to supply the electrolyte to the stacked electrode body 100. Therefore, compared to a configuration that does not include the plate-shaped members 201, 202, the electricity storage module 1 can more easily hold the electrolyte impregnated in the stacked electrode body 100 within the stacked electrode body 100.

[0063] (2) As shown in Fig. 4, the plate-shaped member 201 has a central portion C1 in the direction D2 and both end portions E11 and E12. The plate-shaped member 202 has a central portion C2 in the direction D2 and both end portions E21 and E22. The central portion C1 is thinner than both end portions E11 and E12. The central portion C2 is thinner than both end portions E21 and E22.

[0064] The center portion of the laminated electrode body 100 in the D2 direction is less able to retain electrolyte than the end portions in the D2 direction. This makes it easier for electrolyte to migrate from the center portion of the laminated electrode body 100 in the D2 direction to the periphery of the center portion. Therefore, by making the center portions C1 and C2 of the plate-like members 201 and 202 thinner than the end portions E11, E12, E21, and E22 as in the above configuration, it becomes easier to supply electrolyte to the center portion of the laminated electrode body 100. This makes it possible to improve the electrolyte retention performance of the center portion of the laminated electrode body 100.

[0065] (3) The plate-like members 201, 202 are formed with a plurality of through-holes 290 that penetrate in the D3 direction at a plurality of different positions in the D2 direction. With this configuration, the electrolyte solution can be more easily supplied to the laminated electrode body 100 during injection, compared to a configuration in which the through-holes 290 are not provided. Furthermore, since the electrolyte solution remains in the through-holes 290 even after injection, the electrolyte solution can be more easily supplied into the laminated electrode body 100. This makes it possible to improve the electrolyte retention performance of the laminated electrode body 100.

[0066] (4) The opening area of ​​the through-holes 290 that are closer to the center C1 than the end E11 (or end E12) of the plurality of through-holes 290 is larger than the opening area of ​​the through-holes 290 that are closer to the end E11 (or end E12) than the center C1 of the plurality of through-holes 290. With this configuration, the electrolyte solution can be more easily supplied to the center of the laminated electrode body 100 in the direction D2 during injection. Furthermore, since the electrolyte solution remains in the through-holes 290 even after injection, the electrolyte solution retention performance in the center of the laminated electrode body 100 can be improved.

[0067] (5) The length in the D3 direction of the container 2 and the electrodes (negative electrode 110 and positive electrode 120) is longer than the length in the D1 direction of the container 2 and the electrodes. The length in the D2 direction of the container 2 and the electrodes is longer than the length in the D3 direction of the container 2 and the electrodes. As shown in FIG. 1 , the container 2 has a fifth surface 25 on the D2 direction side. An external connection terminal 27 is formed on the fifth surface 25. The external connection terminal 27 is electrically connected to the stacked electrode body 100.

[0068] With this configuration, the length of the energy storage module 1 in the D2 direction is the longest among the lengths in the D1 direction, the D2 direction, and the D3 direction. Generally, an energy storage module with this shape tends to have poor electrolyte injection properties in the longitudinal direction, that is, the D2 direction. However, with the energy storage module 1, the electrolyte can be supplied to the stacked electrode body 100 through the through-holes 290 and the spaces S1 and S2 formed between the plate-like members 201 and 202 and the stacked electrode body 100. Therefore, with the energy storage module 1, even if the length in the D2 direction is the longest among the lengths in the D1 direction, the D2 direction, and the D3 direction, the electrolyte injection properties and the electrolyte retention properties of the stacked electrode body 100 can be improved.

[0069] <Modification> (1) First Modification In the above description, an example has been given in which the central portions C1 and C2 of the plate-shaped members 201 and 202 are thinner than the end portions E11, E12, E21, and E22, but this is not limiting. The central portions C1 and C2 of the plate-shaped members 201 and 202 may be thicker than the end portions E11, E12, E21, and E22. In this configuration, gas generated within the laminated electrode body 100 during charge and discharge is easily discharged from the end portions E11, E12, E21, and E22. In other words, the gas discharge performance is excellent. In addition, the electrolyte injection and liquid retention performance from the end portions E11, E12, E21, and E22 are excellent.

[0070] (2) Second Modification In the above description, an example has been given of a configuration in which the opening area of ​​the through-holes 290 increases from both end portions E11, E12 toward the center portion C1, but this is not limiting. The plate-like members 201, 202 may be configured so that the opening area of ​​the through-holes 290 decreases from both end portions E11, E12 toward the center portion C1. In such a configuration, gas generated within the laminated electrode body 100 due to charge and discharge can be easily discharged through the through-holes provided at both end portions E11, E12, E21, E22. In other words, the gas discharge properties are excellent.

[0071] (3) Third Modification In the above, the second surface 212 of the plate-shaped member 201 is composed of two flat surfaces (inclined surfaces 212a and 212b). The second surface 222 of the plate-shaped member 202 is also composed of two flat surfaces (inclined surfaces 222a and 222b). However, this is not limited to this. The second surface 212 of the plate-shaped member 201 may be composed of three or more flat surfaces, one or more curved surfaces, or a combination of flat surfaces and curved surfaces.

[0072] Specifically, it is sufficient that at least a portion of the second surface 212 is bent or curved along the D2 direction. The entire second surface 212 does not need to be bent or curved along the D2 direction. It is sufficient that at least a portion of the second surface 212 is bent or curved. Note that "bent or curved" also includes a configuration in which a portion of the plate-shaped member 201 (for example, central portions C1, C2 or end portions E11, E12, E21, E22) is cut out from the second surface 212 side. The same applies to the second surface 222 of the plate-shaped member 202.

[0073] (4) Fourth Modification In the above description, an example has been given of a configuration in which a plurality of through holes 290 are formed in each of the plate-shaped members 201, 202, but the present invention is not limited to this. Instead of the plurality of through holes 290, a plurality of non-through holes may be formed in the plate-shaped members 201, 202. When the plate-shaped members 201, 202 are arranged as shown in FIG. 4, it is preferable to form the plurality of holes on the second surfaces 212, 222 facing the laminated electrode body 100, from the viewpoint of supplying the electrolyte to the laminated electrode body 100. The positions of the plurality of holes may be, for example, the same positions as the plurality of through holes 290.

[0074] (5) Fifth Modification In the above, a plurality of through holes 290 are formed in each of the plate-shaped members 201, 202, but this is not limited to this. One through hole 290 may be formed in each of the plate-shaped members 201, 202. In this case, it is preferable to provide the through hole 290 at or near the center portions C1, C2 of the plate-shaped members 201, 202 in the D2 direction. The same applies when a non-through hole is formed instead of the through hole 290.

[0075] The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present disclosure is defined by the claims, and includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0076] 1 Energy storage module, 2 Housing, 2h Inlet hole, 21, 211, 221 First surface, 22, 212, 222 Second surface, 23, 213, 223 Third surface, 24, 214, 224 Fourth surface, 25, 215, 225 Fifth surface, 26, 216, 226 Sixth surface, 27 External connection terminal, 100 Laminated electrode body, 110 Negative electrode, 120 Positive electrode, 130 Separator, 150, 160 Tab, 201, 202, 203, 204 Plate-shaped member, 212a, 212b, 222a, 222b Inclined surface, 290 Through hole, 301, 302 Tape material, 500 Insulating sheet, C1, C2 Center portion, E11, E12, E21, E22 End, S1, S2 space, T weld area.

Claims

1. A power storage module, a laminated electrode body in which a plurality of electrodes are laminated in a first direction and impregnated with an electrolyte; a housing that houses the stacked electrode body, the container and the stacked electrode body extend in a second direction perpendicular to the first direction, the energy storage module further includes a plate-like member extending in the second direction and disposed in the housing so as to face the stacked electrode body, the plate-like member is disposed such that a third direction perpendicular to the first direction and the second direction corresponds to a thickness direction of the plate-like member; the plate-like member has a surface facing the laminated electrode body, At least a portion of the opposing surface is bent or curved along the second direction, The energy storage module, wherein a space is formed between the opposing surface and the stacked electrode body due to the bending or curvature of the opposing surface.

2. the plate-like member has a central portion and both end portions in the second direction, The energy storage module according to claim 1 , wherein the central portion is thinner than the both end portions.

3. The energy storage module according to claim 1 , wherein the plate-like member has a plurality of through holes formed at different positions in the second direction, each of the through holes passing through the plate-like member in the third direction.

4. 4. The energy storage module according to claim 3, wherein an opening area of ​​a first through hole among the plurality of through holes that is closer to the central portion than one end of the both end portions is larger than an opening area of ​​a second through hole among the plurality of through holes that is closer to the one end portion than the central portion.

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