Energy storage module

Abstract

To provide a power storage module suppressing reduction in holding force of an electrode body while increasing the accommodation space of a case.SOLUTION: In a power storage module 1 based on the present disclosure, a case 200 includes a case body 210 and at least one partition portion 220. The case body 210 has electrical insulation and surrounds the plurality of electrode bodies 100. The partition portion 220 has electrical insulation and is located between the electrode bodies 100 adjacent to each other to partition an accommodation space S of the case body 210. The partition portion 220 has a base 221, and a first projection 222. The base 221 is plate-shaped, and extends along a plane direction orthogonal to a first direction D1. The first projection 222 projects from the base 221 to one side in the first direction D1, and is in contact with one of the electrode bodies 100.SELECTED DRAWING: Figure 4

Description

Technical Field

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

Background Art

[0002] The accommodating portion of the battery case disclosed in Patent Document 1 (Japanese Patent Application Laid-Open No. 2019-106372) has a lower wall and a plurality (for example, three, four, or more) of side walls integrated to form a space inside, has has an open surface facing the lower wall, and one or more (for example, two, three, four, five, or more) partition walls are provided in the space. Thereby, the accommodating portion includes a plurality of battery compartment portions separated by one or more partition walls arranged in the space. Each battery compartment portion can accommodate an electrode assembly respectively.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In order to improve the energy density of the power storage module, it is preferable that the accommodation space in the battery case is large. In the battery case disclosed in Patent Document 1, when increasing the accommodation space in the case, it is conceivable to make the partition wall thinner. However, when the partition wall becomes thinner, it is easier for the partition wall to deform due to the pressure from the electrode body. That is, when the partition wall is thinned, the holding force of the electrode body may decrease.

[0005] The present disclosure has been made in view of the above problems, and an object thereof is to provide a power storage module capable of suppressing a decrease in the holding force of the electrode body while increasing the accommodation space of the case.

Means for Solving the Problems

[0006] The energy storage module according to this disclosure comprises a plurality of electrode bodies and a case. The plurality of electrode bodies are arranged in a first direction. The case houses the plurality of electrode bodies. The case has a case body and at least one partition wall. The case body is electrically insulating and surrounds the plurality of electrode bodies. The partition wall is electrically insulating and is located between adjacent plurality of electrode bodies, partitioning the housing space of the case body. The partition wall has a base and a first projection. The base is plate-shaped and extends along a planar direction perpendicular to the first direction. The first projection protrudes from the base to one side in the first direction and is in contact with one of the plurality of electrode bodies.

[0007] With the above configuration, the storage space of the case can be increased by making the base relatively thin. On the other hand, the thickness of the partition wall is relatively thick in the part composed of the first protrusion and the base. Therefore, by configuring the electrode body to be in contact with this first protrusion, the reduction in the holding force of the electrode body in the storage space of the case can be suppressed. [Effects of the Invention]

[0008] According to this disclosure, it is possible to increase the housing space of the case while suppressing a decrease in the holding force of the electrode body. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view showing an energy storage module according to Embodiment 1. [Figure 2] This is a partially disassembled perspective view of the energy storage module according to Embodiment 1. [Figure 3] Figure 1 is a cross-sectional view of the energy storage module as seen in the direction of the arrow III-III. [Figure 4] Figure 1 is a cross-sectional view of the energy storage module as seen in the direction of the IV-IV arrow. [Figure 5] Figure 1 is a cross-sectional view of the electrode assembly housed in the energy storage module, viewed in the direction of the VV arrow. [Figure 6] This is a partial cross-sectional view of a portion of the energy storage module shown in Figure 2, viewed in the direction of the arrow along the line VI-VI. [Figure 7] These are partial cross-sectional views of energy storage modules according to various modifications of Embodiment 1. [Figure 8] This is a partially disassembled perspective view of the energy storage module according to Embodiment 2. [Figure 9] This is a partially disassembled perspective view of the energy storage module according to Embodiment 3. [Modes for carrying out the invention]

[0010] Embodiments of this disclosure will be described with reference to the drawings. In the drawings referred to below, the same or equivalent components are given the same number.

[0011] (Embodiment 1) Figure 1 is a perspective view showing an energy storage module according to Embodiment 1. Figure 2 is an exploded perspective view of the energy storage module according to Embodiment 1, partially disassembled. Figure 3 is a cross-sectional view of the energy storage module of Figure 1, viewed in the direction of the arrow III-III. Figure 4 is a cross-sectional view of the energy storage module of Figure 1, viewed in the direction of the arrow IV-IV.

[0012] As shown in Figures 1 to 4, the energy storage module 1 according to Embodiment 1 of the present disclosure comprises a plurality of electrode bodies 100, a case 200, at least one connecting conductive member 310, and an external conductive member 320. The plurality of electrode bodies 100 are arranged in a first direction D1. The case 200 houses the plurality of electrode bodies 100. The connecting conductive member 310 is arranged in a third direction D3 with the plurality of electrode bodies 100 and electrically connects adjacent electrode bodies 100 to each other. The third direction D3 is perpendicular to the first direction D1. The second direction D2, which will be described later, is a direction perpendicular to both the first direction D1 and the third direction D3.

[0013] In the present embodiment, the plurality of electrode bodies 100 include a first electrode body 100A, a second electrode body 100B, and a third electrode body 100C. The third electrode body 100C is located opposite the second electrode body 100B when viewed from the first electrode body 100A. In the present embodiment, the second electrode body 100B is located at the outermost end in the first direction D1 among the plurality of electrode bodies 100. The third electrode body 100C is located at the outermost end on the opposite side of the second electrode body 100B in the first direction D1 among the plurality of electrode bodies 100. The plurality of electrode bodies 100 may include four or more electrode bodies.

[0014] FIG. 5 is a cross-sectional view of the electrode body housed in the power storage module of FIG. 1 as viewed in the direction of the V-V line arrow. As shown in FIG. 5, each of the plurality of electrode bodies 100 includes a plurality of electrodes 110, 120 and a separator 130. In the present embodiment, the electrode body 100 is an electrode body for a secondary battery such as a lithium ion secondary battery.

[0015] As shown in FIG. 5, the plurality of electrodes 110, 120 are arranged side by side in the first direction D1. The plurality of electrodes 110, 120 include a plurality of positive electrodes 110 and a plurality of negative electrodes 120.

[0016] Each positive electrode 110 is formed in a rectangular shape that is long in the third direction D3 (the direction perpendicular to the paper surface in FIG. 5). Each positive electrode 110 has a positive electrode current collector foil 112 and positive electrode active material layers 114 provided on both sides of the positive electrode current collector foil 112. The positive electrode current collector foil 112 has a positive electrode tab 112p (see FIGS. 3 and 4) where the positive electrode active material layer 114 is not provided. The positive electrode tab 112p protrudes toward one side in the third direction D3.

[0017] Each negative electrode 120 is formed in a rectangular shape that is long in the third direction D3. Each negative electrode 120 has a negative electrode current collector foil 122 and negative electrode active material layers 124 provided on both surfaces of the negative electrode current collector foil 122. The negative electrode current collector foil 122 has a negative electrode tab 122n (see FIGS. 3 and 4) where the negative electrode active material layer 124 is not provided. The negative electrode tab 122n protrudes toward the other side in the third direction D3.

[0018] The separator 130 insulates between the positive electrode 110 and the negative electrode 120. The separator 130 is made of an insulating material and has minute voids that permit ion permeation. As shown in FIG. 5, the separator 130 is formed in a zigzag shape.

[0019] The separator 130 exhibits a rectangular shape in the state before being formed in a zigzag shape. The separator 130 is disposed while being formed in a zigzag shape between each pair of electrodes 110, 120. The separator 130 has a plurality of intervening portions 132a, a plurality of upward folding portions 132b, a plurality of downward folding portions 132c, and an outermost covering portion 132d.

[0020] Each intervening portion 132a intervenes between a pair of electrodes 110, 120 that are adjacent to each other in one direction. That is, each intervening portion 132a has a function of insulating between the positive electrode 110 and the negative electrode 120. Each intervening portion 132a is composed of a rectangular region.

[0021] Each upward folding portion 132b connects the upper end portion of one intervening portion 132a among the plurality of intervening portions 132a and the upper end portion of an intervening portion 132a adjacent to the one intervening portion 132a on one side in one direction among the plurality of intervening portions 132a. In the present embodiment, the upward folding portion 132b is disposed above the positive electrode 110.

[0022] Each lower folded portion 132c connects the lower end of one of the multiple intervening portions 132a to the lower end of an intervening portion 132a adjacent to the first intervening portion in one direction. In this embodiment, the lower folded portion 132c is located below the negative electrode 120. In other words, the negative electrode 120 is located on the lower folded portion 132c.

[0023] The outermost covering portion 132d covers each upper folded portion 132b and each lower folded portion 132c together. More specifically, the outermost covering portion 132d covers all electrodes 110, 120, all intervening portions 132a, all upper folded portions 132b, and all lower folded portions 132c together by winding around a central axis parallel to the third direction D3. The end portion 132e of the outermost covering portion 132d is set in a range that does not overlap with the positive electrode active material layer 114 and the negative electrode active material layer 124 in one direction. In this embodiment, the end portion 132e of the outermost covering portion 132d is provided below each electrode 110, 120. Note that the circumferential and bottom surfaces of the multiple electrodes 110, 120 and the separator 130 may or may not be covered with an insulating film. The peripheral and bottom surfaces of the multiple electrodes 110, 120 and the separator 130 may be in direct contact with the case 200.

[0024] Figure 6 is a partial cross-sectional view of a portion of the energy storage module in Figure 2, viewed in the direction of the arrow VI-VI. As shown in Figures 1 to 4 and Figure 6, the case 200 has a case body 210 and at least one partition wall portion 220.

[0025] The case body 210 has electrical insulation properties at least on the surface facing the electrode body 100. The case body 210 surrounds a plurality of electrode bodies 100.

[0026] The case body 210 has a bottom wall portion 211, a circumferential side wall portion 212, a hole portion 215, a lid 216, and a welded portion 217.

[0027] The bottom wall portion 211 is made of a resin composition. In the case body 210, the bottom wall portion 211 is located on one side in the second direction D2. The second direction D2 is perpendicular to both the first direction D1 and the third direction D3. The bottom wall portion 211 extends along the first direction D1 and the third direction D3. Viewed from the second direction D2, the bottom wall portion 211 has a rectangular outer shape.

[0028] The circumferential side wall portion 212 is made of a resin composition and is integrally molded with the bottom wall portion 211. The circumferential side wall portion 212 rises from the outer peripheral end of the bottom wall portion 211 in a second direction D2, forming an opening OP that faces away from the bottom wall portion 211.

[0029] The circumferential wall portion 212 has a pair of first wall portions 213 and a pair of second wall portions 214. The pair of first wall portions 213 are aligned in a first direction D1. The pair of first wall portions 213 extend along a third direction D3. The pair of second wall portions 214 are aligned in a third direction D3. The pair of second wall portions 214 extend along a first direction D1.

[0030] The hole 215 is provided to expose a portion of the connecting conductive member 310 to the outside of the case body 210. The hole 215 is closed by the connecting conductive member 310. Specifically, the hole 215 is provided in the circumferential side wall 212, and more specifically, in the second wall 214.

[0031] In this embodiment, the case body 210 has a plurality of holes 215 as described above. Of the plurality of holes 215, the external conductive member 320 is exposed through one hole 215 that is different from the holes 215 described above.

[0032] The lid 216 closes the opening OP. In this embodiment, at least the portion of the lid 216 facing the circumferential side wall portion 212 is made of a resin composition. The lid 216 has a flat or film-like outer shape.

[0033] The lid 216 may be a laminate comprising a resin layer made of the resin composition and a barrier layer. Specifically, the lid 216 may be a laminate film in which a barrier layer made of aluminum or the like is laminated to the resin layer. The lid 216 may also be a plate-like member in which a metal plate such as aluminum is laminated to the resin layer. The barrier layer or metal plate may be placed inside the resin layer.

[0034] The welded portion 217 is formed by heat welding the lid 216 and the circumferential side wall portion 212 to each other. The lid 216 and the circumferential side wall portion 212 may be joined to each other by other known joining methods such as adhesives instead of forming the welded portion 217.

[0035] The partition wall 220 has at least electrical insulation on the surface facing the electrode body 100. The partition wall 220 is located between a plurality of adjacent electrode bodies 100 and divides the housing space S of the case body 210.

[0036] The partition wall portion 220 has a base portion 221, a first projection portion 222, and a second projection portion 223 (see Figure 4). The base portion 221 is a flat plate. The base portion 221 extends along a planar direction perpendicular to the first direction D1. That is, the base portion 221 extends along both the second direction D2 and the third direction D3.

[0037] The first projection 222 protrudes from the base 221 to one side in the first direction D1. The first projection 222 is in contact with the first electrode body 100A, which is one of the plurality of electrode bodies 100.

[0038] The second projection 223 protrudes from the base 221 to the other side in the first direction D1. The second projection 223 is in contact with the second electrode body 100B, which is one of the multiple electrode bodies 100.

[0039] The first protrusion 222 is curved convexly toward the electrode body 100 (i.e., the first electrode body 100A) that is in contact with the first protrusion 222. The second protrusion 223 is curved convexly toward the electrode body 100 (i.e., the second electrode body 100B) that is in contact with the second protrusion 223.

[0040] In this embodiment, the dimension of the first projection 222 in the first direction D1 is substantially constant from one side to the other in the second direction D2 (see Figure 6). However, the dimension of the first projection 222 in the first direction D1 does not have to be substantially constant as described above.

[0041] Figure 7 is a partial cross-sectional view of each modified energy storage module according to Embodiment 1. In Figures 7(A) to 7(C), each modified energy storage module is shown in a cross-sectional view similar to the partial cross-sectional view of energy storage module 1 in Figure 6.

[0042] As shown in Figure 7(A), in the first modified example, the dimension of the first protrusion 222a in the first direction D1 increases toward the bottom wall 211. As shown in Figure 7(B), in the second modified example, the dimension of the first protrusion 222b in the first direction D1 decreases toward the bottom wall 211. As shown in Figure 7(C), in the third modified example, the dimension of the first protrusion 222c in the first direction D1 increases toward the approximate center of the accommodation space S in the second direction D2. The dimension of the second protrusion 223 in the first direction D1 can also be configured similarly to that of the first protrusions 222, 222a, 222b, and 222c.

[0043] The case 200 according to this embodiment has a plurality of partition sections 220. The plurality of partition sections 220 include a first partition section 220A and a second partition section 220B. The plurality of partition sections 220 may include three or more partition sections.

[0044] In the storage space S of the case body 210, a partition wall 220 (first partition wall 220A) forms a first section S1 and a second section S2 adjacent to the first section S1 via the partition wall 220 (first partition wall 220A). In addition, a second partition wall 220B forms a third section S3 adjacent to the first section S1 via the second partition wall 220B in the storage space S. The third section S3 is located opposite the second section S2 when viewed from the first section S1.

[0045] The second partition wall portion 220B, like the first partition wall portion 220A, has a base portion 221, a first projection portion 222, and a second projection portion 223. However, the second projection portion 223 of the second partition wall portion 220B is in contact with the third electrode body 100C.

[0046] Specifically, of the multiple electrode bodies 100, the first electrode body 100A is housed in the first compartment S1. The second electrode body 100B is housed in the second compartment S2. The third electrode body 100C is housed in the third compartment. An electrolyte is injected into the housing space S (first compartment S1, second compartment S2, and third compartment S3). The electrolyte is not shown in the figure. The method of injecting the electrolyte is not particularly limited. The electrolyte may be injected through the opening OP before the opening OP is closed by the lid 216.

[0047] The multiple partition walls 220 are made of a resin composition and are integrally molded with the bottom wall 211 and the circumferential side wall 212. In this embodiment, the multiple partition walls 220 and the lid 216 may or may not be joined to each other by heat welding.

[0048] In this embodiment, the "integrally molded" method described above includes a method in which each component is molded and joined simultaneously in a single step by a known method such as injection molding, or a method in which multiple components are molded separately and then joined to each other by a known joining method such as welding, bonding, or adhesive bonding.

[0049] Here, we will describe the resin compositions that can constitute the bottom wall portion 211, the peripheral side wall portion 212, the lid 216, and the multiple partition wall portions 220 in this embodiment.

[0050] The above resin composition may include, as a base polymer, polycarbonate, polyethylene, polypropylene, polyvinyl, polyamide, polyester, polyphenylene sulfide (PPS), polyphenylene ether, polystyrene, polycyclic olefin copolymer, acrylonitrile-butadiene-styrene copolymer, liquid crystal polymer (LCP), fluororesin, mixtures thereof, alloys thereof, or copolymers thereof. The base polymer is not limited to these.

[0051] The above resin composition may include a polyolefin, a liquid crystal polymer, or a fluororesin as the base polymer. The polyolefin may include high-density polyethylene (HDPE). High-density polyethylene, liquid crystal polymers, or fluororesins have relatively low water vapor permeability. Therefore, Case 200, which includes a resin composition containing these, has improved moisture resistance.

[0052] Liquid crystal polymers may contain structural units derived from oligomers of hydroxybenzoic acid. In addition to oligomers of hydroxybenzoic acid, liquid crystal polymers may further contain two or more selected from the group consisting of HNA (2,6-hydroxynaphthoic acid), TPA (terephthalic acid), IPA (isophthalic acid), HQ (hydroquinone), BP (biphenol), PET (polyethylene terephthalate), and PEN (polyethylene naphthalate), copolymerized with oligomers of hydroxybenzoic acid (HBA).

[0053] Examples of fluororesins include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), or mixtures or copolymers thereof. Fluororesins are hydrophobic. Therefore, based on the total weight of the resin composition, the resin composition may contain, for example, about 20% by weight or less, about 15% by weight or less, about 10% by weight or less, about 3% to about 10% by weight, or about 5% to about 10% by weight of fluororesin. When the fluororesin content is within the above ranges, it is considered that a molded article made from the resin composition has the effect of blocking moisture from the surface of the molded article that comes into contact with the outside air.

[0054] In this embodiment, it is preferable that the base polymer of the resin composition constituting the lid 216 and the base polymer of the resin composition constituting the circumferential side wall portion 212 and the plurality of partition wall portions 220 are the same. This allows these components to be easily welded to each other, thereby easily forming the welded portion 217. From the viewpoint of performing heat welding, it is also preferable that the base polymer be polyethylene or polypropylene.

[0055] The above resin composition may further contain an inorganic desiccant or graphite from the viewpoint of suppressing water vapor transmission. In addition, the above resin composition may further contain substances known as existing moisture barrier materials, other than graphite.

[0056] Next, the connecting conductive member 310 and the external conductive member 320 will be described. In this embodiment, the energy storage module 1 includes a plurality of connecting conductive members 310. The plurality of connecting conductive members 310 includes a first connecting conductive member 310A and a second connecting conductive member 310B. The plurality of connecting conductive members 310 may include three or more connecting conductive members. In addition, in this embodiment, the energy storage module 1 includes a first external conductive member 320A and a second external conductive member 320B as the external conductive member 320.

[0057] The connecting conductive member 310 (first connecting conductive member 310A, second connecting conductive member 310B) has a first end portion 311A, a second end portion 311B, a first inner surface portion 312A, a second inner surface portion 312B, a first outer surface portion 313A, and a second outer surface portion 313B.

[0058] In the first connecting conductive member 310A, the first end portion 311A ​​is one end portion of the first connecting conductive member 310A in the first direction D1 and is embedded in the circumferential side wall portion 212 (one of the second wall portions 214) of the case body 210. The second end portion 311B is the other end portion of the first connecting conductive member 310A in the first direction D1 and is embedded in the circumferential side wall portion 212 (one of the second wall portions 214) of the case body 210.

[0059] In the first connecting conductive member 310A, the first inner surface portion 312A is exposed to the first compartment S1 and is electrically connected to the electrode tab (negative electrode tab 122n) of the first electrode body 100A. The second inner surface portion 312B is exposed to the second compartment S2 and is electrically connected to the electrode tab (positive electrode tab 112p) of the second electrode body 100B.

[0060] In the second connecting conductive member 310B, the first end portion 311A ​​is one end portion of the second connecting conductive member 310B in the first direction D1 and is embedded in the circumferential side wall portion 212 (the other second wall portion 214) of the case body 210. The second end portion 311B is the other end portion of the second connecting conductive member 310B in the first direction D1 and is embedded in the circumferential side wall portion 212 (the other second wall portion 214) of the case body 210.

[0061] In the second connecting conductive member 310B, the first inner surface portion 312A is exposed to the first compartment S1 and is electrically connected to the electrode tab (positive electrode tab 112p) of the first electrode body 100A. The second inner surface portion 312B is exposed to the third compartment S3 and is electrically connected to the electrode tab (negative electrode tab 122n) of the third electrode body 100C.

[0062] In each connecting conductive member 310, the first outer surface portion 313A is located on the opposite side of the first inner surface portion 312A and is exposed to the outside of the case body 210 through the hole 215. Each connecting conductive member 310 is provided with a pressure relief valve 314 that can release the pressure from the first inner surface portion 312A side to the first outer surface portion 313A side.

[0063] In each connecting conductive member 310, the second outer surface portion 313B is located on the opposite side of the second inner surface portion 312B and is exposed to the outside of the case body 210 through another hole 215. Each connecting conductive member 310 is provided with another pressure relief valve 315 that can release the pressure from the second inner surface portion 312B side to the first outer surface portion 313A side.

[0064] The first external conductive member 320A is aligned with the third electrode body 100C in the third direction D3 and is electrically connected to the third electrode body 100C. The second external conductive member 320B is aligned with the second electrode body 100B in the third direction D3 and is electrically connected to the second electrode body 100B.

[0065] Each external conductive member 320 has a third inner surface portion 321, an external connection surface portion 322, and an embedded end portion 323.

[0066] In the first external conductive member 320A, the third inner surface portion 321 is exposed to the housing space S (third compartment S3) and is electrically connected to the electrode tab (positive electrode tab 112p) of the third electrode body 100C. In the second external conductive member 320B, the third inner surface portion 321 is exposed to the housing space S (second compartment S2) and is electrically connected to the electrode tab (negative electrode tab 122n) of the second electrode body 100B.

[0067] In each external conductive member 320, the external connection surface portion 322 is exposed to the outside of the case body 210 in the first direction D1. The embedded end portion 323 is the end opposite to the external connection surface portion 322 in the first direction D1 and is embedded in the case body 210.

[0068] Each external conductive member 320 further has a third outer surface 324. The third outer surface 324 is located on the opposite side of the third inner surface 321. The third outer surface 324 is exposed to the outside of the case body 210 through one of a plurality of holes 215. Each external conductive member 320 is provided with another pressure relief valve 325 that can release the pressure from the third inner surface 321 side to the third outer surface 324 side.

[0069] Each connecting conductive member 310 and each external conductive member 320 is made of a metal such as stainless steel, aluminum, or copper.

[0070] In this embodiment, the energy storage module 1 further comprises a plurality of current collectors 400. Each of the plurality of current collectors 400 is positioned between the positive electrode tab 112p of each electrode body 100 and the connecting conductive member 310 or external conductive member 320, and between the negative electrode tab 122n of each electrode body 100 and the connecting conductive member 310 or external conductive member 320. Each current collector 400 is joined to each positive electrode tab 112p or each negative electrode tab 122n by welding. Each current collector 400 is joined to an adjacent first inner surface portion 312A, second inner surface portion 312B, or third inner surface portion 321 by welding.

[0071] The multiple current collectors 400 may include, for example, a metallic material such as aluminum or copper. Note that the energy storage module 1 does not necessarily include the current collectors 400. If the current collectors 400 are not included, each positive electrode tab 112p and each negative electrode tab 122n may be directly joined to the adjacent first inner surface portion 312A, second inner surface portion 312B, or third inner surface portion 321 by welding.

[0072] As described above, the energy storage module 1 according to Embodiment 1 of the present disclosure comprises a plurality of electrode bodies 100 and a case 200. The plurality of electrode bodies 100 are arranged in a first direction D1. The case 200 houses the plurality of electrode bodies 100. The case 200 has a case body 210 and at least one partition wall portion 220. The case body 210 is electrically insulating and surrounds the plurality of electrode bodies 100. The partition wall portion 220 is electrically insulating and is located between adjacent plurality of electrode bodies 100, partitioning the housing space S of the case body 210. The partition wall portion 220 has a base portion 221 and a first projection portion 222. The base portion 221 is plate-shaped and extends along a planar direction perpendicular to the first direction D1. The first projection 222 protrudes from the base 221 to one side in the first direction D1 and is in contact with one of the multiple electrode bodies 100.

[0073] With the above configuration, the housing space S of the case 200 can be enlarged by making the base portion 221 relatively thin. On the other hand, the thickness of the partition portion 220 is relatively thick in the portion composed of the first protrusion portion 222 and the base portion 221. Therefore, by configuring the first protrusion portion 222 and the electrode body 100 to be in contact, a decrease in the holding force of the electrode body 100 in the housing space S of the case 200 can be suppressed.

[0074] Furthermore, in the energy storage module 1 according to Embodiment 1 of the present disclosure, the first protrusion 222 is curved in a convex shape toward the electrode body 100 that is in contact with the first protrusion 222.

[0075] According to the above configuration, the convex curvature of the first protrusion 222 suppresses the concentration of stress in the portion of the electrode body 100 that is in contact with the first protrusion 222.

[0076] Furthermore, in the energy storage module 1 according to Embodiment 1 of the present disclosure, the dimension of the first protrusion 222a in the first direction D1 may increase as it approaches the bottom wall portion 211.

[0077] According to the above configuration, the electrode body 100 can be easily inserted into the housing space S partitioned by the partition wall 220 from the opening OP side. In addition, the inner surface of the first projection 222a is inclined with respect to the second direction D2 and can function as a so-called draft angle. Therefore, the molding of the case body 210 can be made easier.

[0078] Furthermore, in the energy storage module 1 according to Embodiment 1 of this disclosure, the dimension of the first protrusion 222b in the first direction D1 may decrease as it approaches the bottom wall portion 211.

[0079] According to the above configuration, the first protrusion 222b can suppress displacement of the electrode body 100, which is housed in the housing space S partitioned by the partition wall 220, in the second direction D2.

[0080] (Embodiment 2) The following describes the energy storage module according to Embodiment 2 of this disclosure. In the energy storage module according to Embodiment 2 of this disclosure, the structure of the lid is the main difference from the energy storage module according to Embodiment 1 of this disclosure. Therefore, the same configurations and effects as in Embodiment 1 will not be repeated in the energy storage module according to Embodiment 2 of this disclosure.

[0081] Figure 8 is an exploded perspective view of a partially disassembled energy storage module according to Embodiment 2. As shown in Figure 8, in Embodiment 2 of this disclosure, the lid 216a has a lid body portion 218 and a gasket 219. The gasket 219 is sandwiched between the lid body portion 218 and the peripheral side wall portion 212a. This makes it possible to improve the airtightness of the case body 210 in a relatively simple manner.

[0082] The lid body portion 218 may have the same configuration as the lid 216 in Embodiment 1. From the viewpoint of increasing rigidity, it is preferable that the lid body portion 218 is a plate-shaped member containing a metal plate inside the resin composition. The gasket 219 may be a plate-shaped member or a linear member such as an O-ring. The gasket 219 may be further disposed between the lid body portion 218 and each partition portion 220. The portion of the circumferential side wall portion 212a that is in contact with the gasket 219 may have a shape that follows the outer shape of the gasket 219 (for example, a groove-shaped outer shape).

[0083] The lid 216a may have a further number of fastening members 250. The fastening members 250 are, for example, bolts. The lid body 218 and the circumferential side wall 212a are fixed to each other by the multiple fastening members 250.

[0084] (Embodiment 3) The following describes the energy storage module according to Embodiment 3 of this disclosure. In the energy storage module according to Embodiment 3 of this disclosure, the structure of the lid body differs mainly from that of the energy storage module according to Embodiment 2 of this disclosure. Therefore, the same configurations and effects as in Embodiment 2 will not be repeated in the energy storage module according to Embodiment 3 of this disclosure.

[0085] Figure 9 is an exploded perspective view of a partially disassembled energy storage module according to Embodiment 3. As shown in Figure 9, in this embodiment, the lid body portion 218b has a claw portion 260 provided along its circumferential edge. The circumferential side wall portion 212b has a groove portion 270 provided along the outer surface of the circumferential side wall portion 212b. The lid body portion 218b is fixed by the claw portion 260 fitting into the groove portion 270. In addition, in this embodiment, a weight made of another material may be provided on the central part of the lid body portion 218b. This prevents deformation of the central part of the lid body portion 218b using the fitting portion of the claw portion 260 and the groove portion 270 as a fulcrum.

[0086] It should be noted that the embodiments disclosed herein are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims rather than the description of the embodiments above, and further includes all modifications within the meaning and scope equivalent to the claims. [Explanation of symbols]

[0087] 1 Energy storage module, 100 Electrode body, 100A First electrode body, 100B Second electrode body, 100C Third electrode body, 110 Positive electrode, 112 Positive electrode current collector foil, 112p Positive electrode tab, 114 Positive electrode active material layer, 120 Negative electrode, 122 Negative electrode current collector foil, 122n Negative electrode tab, 124 Negative electrode active material layer, 130 Separator, 132a Intervening part, 132b Upper folded part, 132c Lower folded part, 132d Outermost covering part, 132e Termination, 200 Case, 210 Case body, 211 Bottom wall, 212, 212a, 212b Peripheral side wall, 213 First wall, 214 Second wall, 215 Hole, 216, 216a Cover, 217 Welded parts, 218, 218b Lid body part, 219 Gasket, 220 Partition wall part, 220A First partition wall part, 220B Second partition wall part, 221 Base part, 222, 222a, 222b, 222c First projection part, 223 Second projection part, 250 Fastening member, 260 Claw part, 270 Recessed part, 310 Connecting conductive member, 310A First connecting conductive member, 310B Second connecting conductive member, 311A ​​First end part, 311B Second end part, 312A First inner surface part, 312B Second inner surface part, 313A First outer surface part, 313B Second outer surface part, 314, 315, 325 Pressure relief valve, 320 External conductive member, 320A First external conductive member, 320B Second external conductive member, 321 Third inner surface, 322 external connection surface, 323 embedded end, 324 third outer surface, 400 current collector, OP opening, S housing space, S1 first compartment, S2 second compartment, S3 third compartment.

Claims

[Claim 1] Multiple electrode bodies arranged in the first direction, The system comprises a case for housing the plurality of electrode bodies, The aforementioned case is, A case body having electrical insulation properties and surrounding the plurality of electrode bodies, It has at least one partition wall that is electrically insulating and is located between the plurality of adjacent electrode bodies to partition the housing space of the case body, The partition wall portion has a plate-shaped base portion extending along a planar direction perpendicular to the first direction, and a first projection portion that protrudes from the base portion to one side in the first direction and contacts one of the plurality of electrode bodies. The aforementioned case body is It is made of a resin composition, and has a bottom wall portion located on one side in a second direction perpendicular to the first direction, A circumferential wall portion is made of a resin composition and is integrally molded with the bottom wall portion, and rises from the circumferential end of the bottom wall portion in the second direction, forming an opening that faces away from the bottom wall portion, It has a lid that closes the opening, The partition wall portion is integrally molded with the bottom wall portion and the circumferential wall portion. A power storage module in which the dimensions of the first protrusion in the first direction decrease as it approaches the bottom wall.

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