Power storage module

Abstract

The invention relates to a power storage module. This power storage module is provided with: a laminated electrode body in which a plurality of electrodes are laminated in a first direction and in which an electrolyte solution is impregnated; and a housing body that houses the laminated electrode body. The housing body and the laminated electrode body extend in a second direction perpendicular to the first direction. The power storage module is further provided with a plate-shaped member that extends in the second direction and is disposed in the housing body in a state of facing the laminated electrode body. The plate-like member is disposed so that a third direction perpendicular to the first direction and the second direction becomes the thickness direction of the plate-like member. The plate-like member has an opposing surface that opposes the laminated electrode body. At least a portion of the facing surface is bent or curved in the second direction. A space is formed between the facing surface and the laminated electrode body by bending or bending the facing surface.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a power storage module. BACKGROUND

[0002] In the past, a power storage module provided with a laminated structure body as an electrode body has been known. In Japanese Patent Application Publication No. 2002-198099, as such a power storage module, a sheet-shaped lithium secondary battery is disclosed, which includes a plurality of units of laminated structure bodies in which a positive electrode sheet and a negative electrode sheet are overlapped with a separator or a solid electrolyte layer interposed therebetween as a power generating element, and a tape is wound around the outer periphery of the laminated structure bodies to bundle and fix the plurality of sheet electrodes that constitute the laminated structure bodies. In the sheet-shaped lithium secondary battery, when a work of impregnating an electrolyte into the laminated structure bodies at the time of battery production, the electrolyte is impregnated into each portion of the laminated structure bodies for a short time, and therefore a plurality of through holes are dispersedly provided in the tape that covers the side surface of the laminated structure bodies. SUMMARY

[0003] In the power storage module, in order to maintain the performance of the battery, it is required to keep the electrolyte impregnated in the laminated electrode body within the laminated electrode body. In the sheet-shaped lithium secondary battery of Japanese Patent Application Publication No. 2002-198099, it cannot be said that the performance (liquid retention performance) of keeping the electrolyte impregnated in the laminated electrode body (laminated structure body) within the laminated electrode body is high. Thus, it is desirable to improve the liquid retention performance.

[0004] The present disclosure provides a power storage module in which it is easy to keep the electrolyte impregnated in the laminated electrode body within the laminated electrode body.

[0005] According to an aspect of the present disclosure, a power storage module includes a laminated electrode body in which a plurality of electrodes are laminated in a first direction, and an electrolyte is impregnated in the laminated electrode body, and a housing body that houses the laminated electrode body. The housing body and the laminated 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 in the housing body in a state of facing the laminated electrode body. The plate-shaped member is disposed in a manner that a third direction that is perpendicular to the first direction and the second direction is a direction of a thickness of the plate-shaped member. The plate-shaped member has a facing surface that faces the laminated electrode body. At least a portion of the facing surface is bent or curved along the second direction. A space is formed between the facing surface and the laminated electrode body by the bending or the curving of the facing surface.

[0006] According to such a structure, it is possible to keep the electrolyte in the space formed between the facing surface and the laminated electrode body. Thus, it is easy to supply the electrolyte to the laminated electrode body. Thus, it is easier to keep the electrolyte impregnated in the laminated electrode body within the laminated electrode body than in a structure that does not include the plate-shaped member.

[0007] It is preferable that the plate-like member have a central portion and both end portions in the second direction. The central portion is thinner than the both end portions.

[0008] In general, the central portion of the laminated electrode body in the second direction tends to be more difficult to retain the electrolyte than the both end portions in the second direction. The phenomenon in which the electrolyte moves from the central portion of the laminated electrode body in the second direction to the periphery of the central portion tends to occur. Thus, as in the above-described structure, the central portion of the plate-like member is made thinner than the both end portions, and thus the electrolyte is easily supplied to the central portion of the laminated electrode body in the second direction. Thus, the electrolyte retention performance at the central portion of the laminated electrode body in the second direction can be improved.

[0009] It is preferable that a plurality of through holes each extending in the third direction be formed at different positions in the second direction of the plate-like member. According to such a structure, compared with a structure in which no through hole is provided, the electrolyte is easily supplied to the laminated electrode body at the time of injection. Furthermore, the electrolyte also accumulates in the through hole after injection, and thus the electrolyte is easily supplied to the inside of the laminated electrode body. Therefore, the electrolyte retention performance of the laminated electrode body can be improved.

[0010] It is preferable that an opening area of a first through hole of the plurality of through holes, which is closer to the central portion than one end portion, be larger than an opening area of a second through hole of the plurality of through holes, which is closer to the one end portion than the central portion.

[0011] According to such a structure, the electrolyte is easily supplied to the central portion of the laminated electrode body in the second direction at the time of injection. Furthermore, the electrolyte also accumulates in the through hole after injection, and thus the electrolyte retention performance at the central portion of the laminated electrode body in the second direction can be improved.

[0012] The above and other objects, features, aspects and advantages of the present application will become more apparent from the following detailed description of the present application taken in conjunction with the accompanying drawings, in which: BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a perspective view of a power storage module.

[0014] Figure 2 is a view showing a laminated electrode body included in the power storage module of Figure 1 .

[0015] Figure 3 is a III-III line cross-sectional view of Figure 1 .

[0016] Figure 4 is a view of the plate-like member when viewed in the direction of the arrow IV shown in Figure 3 .

[0017] Figure 5 is a view of the plate-like member when viewed in the direction of the arrow V shown inFigure 4 a case where the plate-like member is viewed from above in a state where the plate-like member is in a horizontal posture. DETAILED DESCRIPTION

[0018] Hereinafter, an embodiment of the present disclosure will be explained in detail with reference to the drawings. Further, in the embodiment shown below, the same signs are attached to the same or common parts in the drawings, and the explanation thereof is not repeated.

[0019] Figure 1 is a perspective view of the power storage module of the present embodiment. Figure 2 is a view showing a laminated electrode body included in the power storage module of Figure 1 . As shown in Figure 1 and Figure 2 , the power storage module 1 is in the shape of a blade. The power storage module 1 is provided with a laminated electrode body 100 and a housing body 2 that houses the laminated electrode body 100. Further, hereinafter, for the sake of convenience, except at the time of injection of an electrolyte solution described later, the case where the power storage module 1 is in a posture where the D3 direction shown in Figure 1 , 2 or the like is the vertical direction (more specifically, the orientation of the D31 described later is the upward orientation) will be explained as an example.

[0020] In the present example, the power storage module 1 is a lithium iron phosphate ion (LFP) type battery. However, it is not limited thereto, and the power storage module 1 can also be a 3-element type (NMC) battery. The power storage module 1 is mounted, for example, on an electric vehicle that travels using driving force obtained by electric energy. More specifically, a battery pack including a plurality of power storage modules 1 arranged in a predetermined direction is mounted on the electric vehicle. The battery pack is installed on the vehicle body of the electric vehicle. The battery pack constitutes a part of the vehicle body. The battery pack is made to function as a structural body of the vehicle body.

[0021] As shown in Figure 1 , the housing body 2 is in the shape of a substantially rectangular parallelepiped. In the present example, the housing body 2 is a frame body made of metal. The housing body 2 has a first surface to a sixth surface 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 outer peripheral surface of the housing body 2 is constituted by the first surface 21, the second surface 22, the third surface 23, and the fourth surface 24.

[0022] The fifth surface 25 and the sixth surface 26 are end surfaces of the housing body 2. The first surface 21 is a top surface, the second surface 22 is a bottom surface, and the third surface 23 and the fourth surface 24 are side surfaces. An external connection terminal 27 on the negative electrode side is provided on the fifth surface 25. An external connection terminal (not shown) on the positive electrode side is provided on the sixth surface 26.

[0023] The D1 direction is the width direction of the power storage module 1. As shown in Figure 2As shown, the plurality of electrodes of the stacked electrode body 100 are stacked in the Dl direction (stacking direction). In detail, in the stacked electrode body 100, the negative electrode 110 and the positive electrode 120 are stacked in the Dl direction with the separator 130 interposed therebetween. The stacked electrode body 100 further has 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 by collecting copper foils. The tab 160 is made by collecting aluminum foils.

[0024] As shown, the power storage module 1 and the housing 2 extend in the D2 direction. As shown, the stacked electrode body 100 is in a substantially rectangular parallelepiped shape. The stacked electrode body 100 extends in the D2 direction. The D2 direction is perpendicular to the Dl direction. The D2 direction is the longitudinal direction of the power storage module 1, the housing 2, and the stacked electrode body 100. The D3 direction is perpendicular to the Dl direction and the D2 direction. The D3 direction is the height direction of the power storage module 1. Figure 1 Figure 2 As shown, the power storage module 1 and the housing 2 extend in the D2 direction. As shown, the stacked electrode body 100 is in a substantially rectangular parallelepiped shape. The stacked electrode body 100 extends in the D2 direction. The D2 direction is perpendicular to the Dl direction. The D2 direction is the longitudinal direction of the power storage module 1, the housing 2, and the stacked electrode body 100. The D3 direction is perpendicular to the Dl direction and the D2 direction. The D3 direction is the height direction of the power storage module 1.

[0025] The Dl direction is the short side direction in each of the first face 21, the second face 22, the fifth face 25, and the sixth face 26. The D2 direction is the long side direction in the first face to the fourth face 21 to 24. The D3 direction is the short side direction in the third face and the fourth face 23, 24, and is the long side direction in the fifth face and the sixth face 25, 26.

[0026] The liquid injection hole 2h is formed in the fifth face 25 for injecting an electrolyte into the inside of the housing 2. The liquid injection hole 2h is formed on the first face 21 side than the second face 22 of the housing 2. The liquid injection hole 2h is formed on the first face 21 side than the external connection terminal 27. Further, in the state shown in FIG. 1, the electrolyte has been injected into the inside of the housing 2, so the liquid injection hole 2h is in a plugged state. The liquid injection hole 2h can be temporarily plugged by inserting a removable plug into the liquid injection hole 2h. Alternatively, the liquid injection hole 2h can be plugged with resin or metal so that the electrolyte cannot be injected again as long as the through hole is not opened. Figure 1

[0027] At the time of manufacturing the power storage module 1 or the like, when the electrolyte is injected from the liquid injection hole 2h, the posture of the power storage module 1 is maintained in such a manner that the D2 direction becomes a substantially vertical direction and the fifth face 25 is on the upper side than the sixth face 26. Due to the weight of the electrolyte, the electrolyte flows from the fifth face 25 side to the sixth face 26 side. Further, the electrolyte has a certain degree of viscosity, so it falls within the housing 2 at a relatively slow speed. Thus, the electrolyte can be allowed to soak into the stacked electrode body 100.

[0028] ​​In the present example, the liquid injection hole 2h is formed on the first face 21 side than the external connection terminal 27, but is not limited thereto. The liquid injection hole 2h can also be formed on the second face 22 side than the external connection terminal 27. The liquid injection hole 2h can also be formed on the third face 23 side than the external connection terminal 27. The liquid injection hole 2h can also be formed on the fourth face 24 side than the external connection terminal 27.

[0029] Further, in the present example, an example in which the liquid injection hole 2h is formed on the fifth face 25 is described, but is not limited thereto. For example, the liquid injection hole 2h can be formed on the sixth face 26. The liquid injection hole 2h can also be formed on the first face 21 or the second face 22. In the case where the liquid injection hole 2h is formed on the first face 21 or the second face 22, the liquid injection hole 2h is preferably formed on the end portion side (fifth face 25 side or sixth face 26 side) than the central portion in the longitudinal direction of the housing 2 from the viewpoint of the liquid injection property. The liquid injection hole 2h can also be formed on the third face 23 or the fourth face 24. The formation position of the liquid injection hole 2h is not particularly limited.

[0030] As described above, the power storage module 1 is in a blade shape. Thus, the housing 2 is also in a blade shape. The laminated electrode body 100 housed in the housing 2 is also in a blade shape. Thus, 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 and the negative electrode 110 and the positive electrode 120. Further, the length in the D2 direction of the housing 2 and the negative electrode 110 and the positive electrode 120 is longer than the length in the D3 direction of the housing and the negative electrode 110 and the positive electrode 120.

[0031] As one example, the length in the D3 direction of the housing 2 is 6 to 7 times the length in the D1 direction of the housing 2. As one example, the length in the D2 direction of the housing 2 is 10 to 11 times the length in the D3 direction of the housing 2. However, the ratio of the length in the D1 direction of the housing 2, the length in the D2 direction of the housing 2, and the length in the D3 direction of the housing 2 is not limited thereto.

[0032] Figure 3 is a cross-sectional view taken along the III-III line of FIG. 1. As shown in FIG. 2, the power storage module 1 includes the housing 2, the laminated electrode body 100, the plate-shaped members 201, 202, the band materials 301, 302, and the insulating sheet 500 in addition to the housing 2 and the laminated electrode body 100. Figure 1 Figure 3 The plate-shaped members 201, 202, the band materials 301, 302, and the insulating sheet 500 are housed in the housing 2 like the laminated electrode body 100. The plate-shaped members 201, 202, the band materials 301, 302, and the insulating sheet 500 are disposed between the laminated electrode body 100 and the housing 2 (gap).

[0033] The plate-shaped members 201, 202, the band materials 301, 302, and the insulating sheet 500 are housed in the housing 2 like the laminated electrode body 100. The plate-shaped members 201, 202, the band materials 301, 302, and the insulating sheet 500 are disposed between the laminated electrode body 100 and the housing 2 (gap). ​

[0034] The plate-shaped members 201 and 202 are insulators. In this example, the plate-shaped members 201 and 202 are formed of a resin. To prevent short circuits between the positive electrode 120 and the negative electrode 110 in the stacked electrode assembly 100, the plate-shaped members 201 and 202 are formed of an insulating material. Furthermore, as long as the insulation distance between the plate-shaped members 201 and 202 and the stacked electrode assembly 100 is sufficiently maintained, the plate-shaped members 201 and 202 do not necessarily need to be insulators.

[0035] As a material constituting the plate-like members 201 and 202, polypropylene is used, for example, but the material is not limited thereto, and polyethylene, polyphenylene sulfide, polyetheretherketone, or PET (polyethylene terephthalate) may also be used.

[0036] The plate-shaped member 201 is arranged in a state opposite to the stacked electrode body 100 within the container 2. The plate-shaped member 201 is arranged above the stacked electrode body 100. Specifically, the plate-shaped member 201 is arranged directly above the stacked electrode body 100. The plate-shaped member 201 is provided on the first surface 21 side of the container 2. The plate-shaped member 201 is oriented in the direction D31 relative to the stacked electrode body 100. As described above, the direction D31 is vertically upward.

[0037] The plate-shaped member 202, like the plate-shaped member 201, is arranged within the container 2 so as to face the stacked electrode body 100. The plate-shaped member 202 is arranged below the stacked electrode body 100. Specifically, the plate-shaped member 202 is arranged directly below the stacked electrode body 100. The plate-shaped member 202 is disposed on the second surface 22 side of the container 2. The plate-shaped member 202 is oriented in a direction D32 relative to the stacked electrode body 100. The direction D32 is vertically downward.

[0038] Figure 4 It is Figure 3 The diagram shows the case where the plate-like members 201 and 202 are viewed in the direction of arrow IV. Figure 4 201 and 202 are side views of the plate-like members 201 and 202. Figure 4 As shown, the plate-like members 201 and 202 extend in the direction D2. The plate-like members 201 and 202 are arranged in the housing 2 so that the direction D3 becomes the thickness direction of the plate-like member 201.

[0039] The plate-like member 201 has a central portion C1 in the direction D2 and two end portions E11 and E12 in the direction D2. The end portion E11 is Figure 1 The end portion E12 is the end portion on the side opposite to the end portion E11. The thickness of the center portion C1 is different from that of the two end portions E11 and E12. Figure 4In the example, the thickness of the central portion C1 is thinner than that of the two end portions E11 and E12.

[0040] The plate-like 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 container 2. The first surface 211 is the surface on the opposite side to the stacked electrode body 100. In this example, the first surface 211 is a flat surface. Figure 3 as well as Figure 4 In the state of , the first surface 211 is the top surface. The first surface 211 is parallel to the stacked electrode body 100.

[0041] The second surface 212 is the surface facing the stacked electrode body 100. Figure 3 as well as Figure 4 In the state, the second surface 212 is the bottom surface. The second surface 212 is the opposite surface to the stacked electrode body 100. The second surface 212 is bent along the D2 direction. In this example, the second surface 212 is bent at the central portion C1. The second surface 212 retreats toward D31. Specifically, in this example, the second surface 212 includes an inclined surface 212a and an inclined surface 212b. In detail, the second surface 212 includes, along the D2 direction, an area where the separation distance between the second surface 212 and the stacked electrode body 100 is less than a reference value (length) in the entire D1 direction, and an area where the separation distance is longer than the reference value in the entire D1 direction.

[0042] In this example, inclined surfaces 212a and 212b are flat surfaces. They are inclined along the direction D2. Each of inclined surfaces 212a and 212b is tilted so that the thickness of the central portion C1 of the plate-like member 201 is thinner than the thickness of the end portions E11 and E12. This creates a space S1 for storing the electrolyte between inclined surfaces 212a and 212b and the stacked electrode assembly 100.

[0043] As described above, the first surface 211 is parallel to the laminated electrode assembly 100. Therefore, the thickness of the plate-like member 201 gradually decreases toward the center portion C1 due to the inclined surfaces 212a and 212b. The plate-like member 201 has portions thicker than a predetermined thickness and portions less than the predetermined thickness due to the inclined surfaces 212a and 212b.

[0044] The third surface 213 is the surface on the third surface 23 side of the container 2. The fourth surface 214 is the surface on the fourth surface 24 side of the container 2. The third surface 213 and the fourth surface 214 are side surfaces of the plate-like 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.

[0045] The plate-like member 202 has a central portion C2 in the direction D2 and two end portions E21 and E22 in the direction D2. The end portion E21 is Figure 1The end portion on the terminal 27 side is shown. The end portion E22 is the end portion on the side opposite to the end portion El l. The central portion C2 is different in thickness from the both end portions E21, E22. In Figure 4 In this example, the central portion C2 is thinner than the both end portions E21, E22.

[0046] The plate-shaped member 202 also has a first face to a sixth face 221 to 226. The first face 221 is the face on the second face 22 side of the housing body 2. The first face 221 is the face on the side opposite to the laminated electrode body 100. In this example, the first face 221 is a flat face. In Figure 3 and Figure 4 In this state, the first face 221 is a bottom face. The first face 221 is parallel to the laminated electrode body 100.

[0047] The second face 222 is the face on the laminated electrode body 100 side. In Figure 3 and Figure 4 In this state, the second face 222 is a top face. The second face 222 is the opposing face opposite to the laminated electrode body 100. The second face 222 is bent along the D2 direction. In this example, the second face 212 is bent at the central portion Cl. The second face 222 retreats toward the D32 direction. Specifically, in this example, the second face 222 includes an inclined face 222a and an inclined face 222b. In detail, the second face 222, like the second face 212 of the plate-shaped member 201, includes a region in which the separation distance between the second face 222 and the laminated electrode body 100 is below a reference value in the entire Dl direction and a region in which the separation distance is longer than the reference value along the D2 direction.

[0048] In this example, the inclined face 222a and the inclined face 222b are flat faces. The inclined face 222a and the inclined face 222b are inclined along the D2 direction. The inclined face 222a and the inclined face 222b are respectively inclined in a manner such that the thickness of the central portion C2 of the plate-shaped member 202 is thinner than the thickness of the both end portions E21, E22. Thus, between the inclined face 222a, 222b and the laminated electrode body 100, a space S2 in which an electrolytic solution is housed is formed.

[0049] As described above, the first face 221 is parallel to the laminated electrode body 100, so the plate-shaped member 202 gradually thins toward the central portion C2 due to the inclined face 222a, 222b. The plate-shaped member 202 has a portion in which the thickness is thicker than a reference thickness and a portion in which the thickness is below the reference thickness due to the inclined face 222a, 222b.

[0050] The third surface 223 is the surface on the third surface 23 side of the container 2. The fourth surface 224 is the surface on the fourth surface 24 side of the container 2. The third surface 223 and the fourth surface 224 are side surfaces of the plate-like 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.

[0051] In this example, the plate-shaped member 202 has a shape symmetrical to the plate-shaped member 201 with respect to the laminated electrode body 100. However, the present invention is not limited thereto.

[0052] like Figure 3 As shown, the plate-like member 201 is fixed to the stacked electrode assembly 100 using a tape 301. The tape 301 extends in the direction D2. The tape 301 covers all or part of the first surface 211 of the plate-like member 201. The tape 301 also covers all or part of the third and fourth surfaces 213 and 214 of the plate-like member 201. The tape 301 covers a portion of the stacked electrode assembly 100.

[0053] The plate-like member 202 is fixed to the stacked electrode assembly 100 by a tape member 302. The tape member 302 extends in the direction D2. The tape member 302 covers all or part of the first surface 221 of the plate-like member 202. The tape member 302 covers all or part of the third and fourth surfaces 223 and 224 of the plate-like member 202. The tape member 302 covers a portion of the stacked electrode assembly 100.

[0054] The insulating sheet 500 insulates the stacked electrode assembly 100 from the container 2. The insulating sheet 500 covers the stacked electrode assembly 100 so that the stacked electrode assembly 100 does not come into contact with the container 2. The insulating sheet 500 is provided between the stacked electrode assembly 100 and the container 2 (specifically, the inner surface of the container) to prevent short circuits in the stacked electrode assembly 100.

[0055] 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.

[0056] The two ends of the insulating sheet 500 are welded together. In a state where the plate-like members 201 and 202 are fixed to the stacked electrode body 100 by the tape materials 301 and 302, the insulating sheet 500 is wound around the tape materials 301 and 302, the plate-like members 201 and 202, and the stacked electrode body 100. Thereafter, the two ends of the insulating sheet 500 are welded together to obtain Figure 3The illustrated insulating sheet 500. In the fusion region T, the end portions of the insulating sheet 500 coincide with each other. The fusion region T extends in the D2 direction. Further, the insulating sheet 500 can also be formed by joining a plurality of insulating sheets.

[0057] Further, as a raw material constituting the insulating sheet 500, for example, polypropylene is used. Not limited thereto, polyethylene, polyphenylene sulfide, polyether ether ketone, nylon, or PET (polyethylene terephthalate), or the like can also be used.

[0058] Figure 5 is a view of the case where the plate-shaped member 201 is observed from the direction of the arrow V Figure 4 is a view of the case where the plate-shaped member 201 is observed from above in the state of Figure 5 Figure 4 is a view of the case where the plate-shaped member 201 is observed from above in the state of

[0059] As illustrated in Figure 5 , in the plate-shaped member 201, a plurality of through-holes 290 each of which penetrates in the D3 direction are formed at different positions in the D2 direction. In detail, in the plate-shaped member 201, a plurality of through-holes 290 are formed from the first face 211 toward the second face 212 which is the back face of the first face 211. The plurality of through-holes 290 are aligned in one row in the D2 direction. Further, not limited thereto, the plurality of through-holes 290 can also be aligned in a plurality of rows in the D2 direction.

[0060] In the present example, the opening area of the through-holes 290 of the plurality of through-holes 290 on the central portion C1 side than the end portions E11 (or the end portions E12) is larger than the opening area of the through-holes 290 of the plurality of through-holes 290 on the end portions E11 (or the end portions E12) side than the central portion C1. In detail, as approaching the central portion C1 from the both end portions E11, E12, the opening area of the through-holes 290 becomes larger. This is in order to easily supply the electrolytic solution to the central portion in the D2 direction of the laminated electrode body 100. Further, not limited thereto, the opening area of each of the through-holes 290 can also be the same.

[0061] The separation distance of each of the through-holes 290 from each other can be constant or different. In the case where the opening area of each of the through-holes 290 is the same, according to the viewpoint of easily supplying the electrolytic solution to the central portion in the D2 direction of the laminated electrode body 100, it is preferable to form the through-holes 290 more on the central portion C1 side than the both end portions E11, E12.

[0062] The plate-shaped member 202 also has the plurality of through-holes 290 similarly to the plate-shaped member 201. In the present example, the plate-shaped member 202 has the same structure as the plate-shaped member 201, so here, the description of each of the through-holes 290 of the plate-shaped member 202 is omitted.

[0063] <CONCLUSION>​

[0064] (1) As shown in FIG. 1, the power storage module 1 includes a stacked electrode body 100 in which a plurality of electrodes are stacked in a D1 direction, and an electrolyte solution is impregnated in the stacked electrode body 100, and a housing body 2 that houses the stacked electrode body 100. The housing body 2 and the stacked electrode body 100 extend in a D2 direction that is perpendicular to the D1 direction. Figure 1 Figure 2 As shown in FIG. 1, the power storage module 1 further includes plate-shaped members 201, 202 that extend in the D2 direction, and are disposed in the housing body 2 in a state of facing the stacked electrode body 100. Figure 3 Figure 4 The plate-shaped members 201, 202 are disposed in a manner that a D3 direction that is perpendicular to the D1 direction and the D2 direction becomes a direction of thickness of the plate-shaped members 201, 202. As shown in FIG. 1, the plate-shaped members 201, 202 have second faces 212, 222 that face the stacked electrode body 100. The second faces 212, 222 are bent along the D2 direction. Due to the bending of the second faces 212, 222, spaces S1, S2 are formed between the second faces 212, 222 and the stacked electrode body 100.

[0065] According to such a structure, the electrolyte solution can be held in the spaces S1, S2 (gaps) between the second faces 212, 222 and the stacked electrode body 100. Thus, it is easy to supply the electrolyte solution to the stacked electrode body 100. Thus, the power storage module 1 is easy to hold the electrolyte solution impregnated in the stacked electrode body 100 in the stacked electrode body 100, compared to a structure that does not include the plate-shaped members 201, 202. Figure 4 The plate-shaped members 201, 202 are disposed in a manner that a D3 direction that is perpendicular to the D1 direction and the D2 direction becomes a direction of thickness of the plate-shaped members 201, 202. As shown in FIG. 1, the plate-shaped members 201, 202 have second faces 212, 222 that face the stacked electrode body 100. The second faces 212, 222 are bent along the D2 direction. Due to the bending of the second faces 212, 222, spaces S1, S2 are formed between the second faces 212, 222 and the stacked electrode body 100.

[0066] (2) As shown in FIG. 1, the plate-shaped member 201 has a central portion C1 and both end portions E11, E12 in the D2 direction. The plate-shaped member 202 has a central portion C2 and both end portions E21, E22 in the D2 direction. The central portion C1 is thinner than the both end portions E11, E12 in thickness. The central portion C2 is thinner than the both end portions E21, E22 in thickness.

[0067] Figure 4 The central portion of the stacked electrode body 100 in the D2 direction is difficult to hold the electrolyte solution, compared to the both end portions in the D2 direction. It is easy to occur a situation in which the electrolyte solution moves from the central portion of the stacked electrode body 100 to the periphery of the central portion. Thus, as in the above-described structure, the central portions C1, C2 of the plate-shaped members 201, 202 are made thinner than the both end portions E11, E12, E21, E22, so that it is easy to supply the electrolyte solution to the central portion of the stacked electrode body 100. Thus, it is possible to improve the liquid retention performance of the electrolyte solution at the central portion of the stacked electrode body 100.

[0068] The central portion of the stacked electrode body 100 in the D2 direction is difficult to hold the electrolyte solution, compared to the both end portions in the D2 direction. It is easy to occur a situation in which the electrolyte solution moves from the central portion of the stacked electrode body 100 to the periphery of the central portion. Thus, as in the above-described structure, the central portions C1, C2 of the plate-shaped members 201, 202 are made thinner than the both end portions E11, E12, E21, E22, so that it is easy to supply the electrolyte solution to the central portion of the stacked electrode body 100. Thus, it is possible to improve the liquid retention performance of the electrolyte solution at the central portion of the stacked electrode body 100. ​​​

[0069] (3) In the plate-shaped members 201, 202, a plurality of through-holes 290 each of which penetrates in the D3 direction are formed at different positions in the D2 direction. According to such a structure, compared with a structure in which the through-holes 290 are not provided, it is easy to supply the electrolyte to the laminated electrode body 100 at the time of injection. Furthermore, after injection, the electrolyte also accumulates in the through-holes 290, so it is easy to supply the electrolyte to the laminated electrode body 100. Therefore, it is possible to improve the electrolyte retention performance of the laminated electrode body 100.

[0070] (4) The opening area of the through-holes 290 of the plurality of through-holes 290 that are on the central portion Cl side than the end portion El 1 (or the end portion E12) is larger than the opening area of the through-holes 290 of the plurality of through-holes 290 that are on the end portion El 1 (or the end portion E12) side than the central portion Cl. According to such a structure, at the time of injection, it is easy to supply the electrolyte to the central portion of the laminated electrode body 100 in the D2 direction. Furthermore, after injection, the electrolyte also accumulates in the through-holes 290, so it is possible to improve the electrolyte retention performance of the laminated electrode body 100 at the central portion.

[0071] (5) The length in the D3 direction of the housing 2 and the electrode (the negative electrode 110 and the positive electrode 120) is longer than the length in the D1 direction of the housing 2 and the electrode. The length in the D2 direction of the housing 2 and the electrode is longer than the length in the D3 direction of the housing 2 and the electrode. As shown in FIG. 1, the housing 2 has a fifth face 25 on the D2 direction side. An external connection terminal 27 is formed on the fifth face 25. The external connection terminal 27 is electrically connected to the laminated electrode body 100. Figure 1

[0072] According to such a structure, the length in the D2 direction is the longest among the lengths in the D1 direction, the D2 direction, and the D3 direction of the power storage module 1. Generally, in a power storage module of such a shape, the injection property in the D2 direction as the long side direction tends to deteriorate. However, according to the power storage module 1, it is possible to supply the electrolyte to the laminated electrode body 100 via the through-holes 290 and the spaces S1, S2 formed between the plate-shaped members 201, 202 and the laminated electrode body 100. Thus, according to the power 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, it is possible to improve the injection property and the retention property of the electrolyte of the laminated electrode body 100.

[0073] <Modification Example>

[0074] (1) First Modification Example

[0075] ​In the above, an example in which the thickness of the central portions C1, C2 of the plate-shaped members 201, 202 is thinner than the thickness of the both end portions E11, E12, E21, E22 is described, but is not limited thereto. The central portions C1, C2 of the plate-shaped members 201, 202 can be thicker than the both end portions E11, E12, E21, E22. In the case of such a structure, it is easy to discharge gas generated in the laminated electrode body 100 due to charge and discharge from the both end portions E11, E12, E21, E22. That is, it is excellent in gas dischargeability. In addition, it is excellent in electrolyte injectionability and liquid retention from the both end portions E11, E12, E21, E22.

[0076] (2) Second Modified Example

[0077] In the above, an example in which the opening area of the through-hole 290 becomes larger as it approaches the central portion C1 from the both end portions E11, E12 is described, but is not limited thereto. The plate-shaped members 201, 202 can be configured such that the opening area of the through-hole 290 becomes smaller as it approaches the central portion C1 from the both end portions E11, E12. In the case of such a structure, it is easy to discharge gas generated in the laminated electrode body 100 due to charge and discharge from the through-hole provided in the both end portions E11, E12, E21, E22. That is, it is excellent in gas dischargeability.

[0078] (3) Third Modified Example

[0079] In the above, the second face 212 of the plate-shaped member 201 is composed of two planes (inclined faces 212a, 212b). The second face 222 of the plate-shaped member 202 is also composed of two planes (inclined faces 222a, 222b). However, it is not limited thereto. The second face 212 of the plate-shaped member 201 can be composed of three or more planes, one or more curved surfaces, or a combination of planes and curved surfaces.

[0080] In detail, at least a part of the second face 212 can be bent or curved in the D2 direction. The entire second face 212 need not be bent or curved in the D2 direction. At least a part of the second face 212 can be bent or curved. Further, bending or curving also includes a structure in which a part of the plate-shaped member 201 (for example, the central portions C1, C2 or the end portions E11, E12, E21, E22) is cut from the second face 212 side. In this regard, the second face 222 of the plate-shaped member 202 is the same.

[0081] (4) Fourth Modified Example

[0082] In the above, an example in which a plurality of through-holes 290 are formed in each of the plate-shaped members 201, 202 is described, but the present application is not limited thereto. A plurality of holes that are not through-holes can be formed in the plate-shaped members 201, 202. In the case where the plate-shaped members 201, 202 are configured as described above, the plurality of holes can be formed in the second surfaces 212, 222 that face the laminated electrode body 100. The positions of the plurality of holes can be the same as the positions of the plurality of through-holes 290. Figure 4 In the case where the plate-shaped members 201, 202 are configured as described above, from the viewpoint of supplying an electrolyte to the laminated electrode body 100, it is preferable that the plurality of holes be formed in the second surfaces 212, 222 that face the laminated electrode body 100. The positions of the plurality of holes can be the same as the positions of the plurality of through-holes 290.

[0083] (5) Fifth Modified Example

[0084] In the above, a plurality of through-holes 290 are formed in each of the plate-shaped members 201, 202, but the present application is not limited thereto. One through-hole 290 can be formed in each of the plate-shaped members 201, 202. In this case, it is preferable that the through-hole 290 be provided at the center C1, C2 of the D2 direction of the plate-shaped members 201, 202 or in the vicinity of the center C1, C2. The same applies to the case where a hole that is not a through-hole is formed instead of the through-hole 290.

[0085] Embodiments of the present application have been described, but the disclosed embodiments should be considered as illustrative in all points and not restrictive. The scope of the present application is shown by the claims, and intended to include all modifications within the meaning and range equivalent to the claims.

Claims

1. An electricity storage module comprising: a stacked electrode body in which a plurality of electrodes are stacked in a first direction and in which an electrolyte solution is impregnated; and a housing body that houses the stacked electrode body, the housing body and the stacked electrode body extending in a second direction that is perpendicular to the first direction, the electricity storage module further comprising a plate-shaped member that extends in the second direction and is disposed in the housing body in a state of facing the stacked electrode body, the plate-shaped member being disposed in a manner such that a third direction that is perpendicular to the first direction and the second direction is a direction of a thickness of the plate-shaped member, the plate-shaped member having a facing surface that faces the stacked electrode body, at least a portion of the facing surface being bent or curved along the second direction, and a space being formed between the facing surface and the stacked electrode body by the bending or the curving of the facing surface.

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

3. The electricity storage module according to claim 1 or 2, wherein a plurality of through holes that respectively penetrate in the third direction are formed at different positions of the plate-shaped member in the second direction.

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

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