Energy storage module

Abstract

To provide a miniaturized power storage module.SOLUTION: In a housing space S of a case main body 210 in a power storage module 1 based on the present disclosure, a first section S1 and a second section S2 that is adjacent to the first section S1 via an interference part 220 are formed by the interference part 220. A first end part 311A is an end part on one side of a connection conductive member 310 in a first direction D1 and is embedded into the case main body 210. A second end part 311B is an end part on the other side of a connection conductive member 310 in the first direction D1 and is embedded into the case main body 210. A first internal surface part 312A is exposed to the first section S1 and is electrically connected to a first electrode body 100A housed in the first section S1 of a plurality of electrode bodies 100. A second inner surface part 312B is exposed to the second section S2 and is electrically connected to a second electrode body 100B housed in the second section S2 of the plurality of electrode bodies 100.SELECTED DRAWING: Figure 4

Description

Technical Field

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

Background Art

[0002] The housing 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, 3, 4, or more) of side walls integrated to form a space inside, has an open surface facing the lower wall, and one or more (for example, 2, 3, 4, 5, or more) partition walls are provided in the space. Thereby, the housing 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. Further, the above-described battery case further includes a lid portion for closing the open surface of the housing portion. The lid portion can have a positive terminal and a negative terminal.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When electrode assemblies are accommodated in each of a plurality of battery compartment portions as disclosed in Patent Document 1, the terminals protruding on the lid portion are connected to each other by a connection member such as a bus bar. Since the connection member is arranged outside the case, the power storage module becomes larger.

[0005] The present disclosure has been made in view of the above problems, and an object thereof is to provide a miniaturized power storage module.

Means for Solving the Problems

[0006] The energy storage module according to this disclosure comprises a plurality of electrode bodies, a case, and at least one connecting conductive member. The plurality of electrode bodies are arranged in a first direction. The case houses the plurality of electrode bodies. The connecting conductive member is arranged with the plurality of electrode bodies in a second direction and electrically connects adjacent electrode bodies to each other. The second direction is perpendicular to the first direction. 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 electrode bodies, partitioning the housing space of the case body. The housing space of the case body is divided into a first compartment and a second compartment adjacent to the first compartment via the partition wall. The connecting conductive member has a first end, a second end, a first inner surface, and a second inner surface. The first end is one end of the connecting conductive member in the first direction and is embedded in the case body. The second end is the other end of the connecting conductive member in the first direction and is embedded in the case body. The first inner surface is exposed to the first compartment and is electrically connected to the first electrode body housed in the first compartment among the multiple electrode bodies. The second inner surface is exposed to the second compartment and is electrically connected to the second electrode body housed in the second compartment among the multiple electrode bodies.

[0007] According to the above configuration, the connecting conductive member electrically connects the first electrode body and the second electrode body, while being at least partially embedded in the case body in the first direction. Therefore, the energy storage module can be miniaturized. [Effects of the Invention]

[0008] According to this disclosure, a miniaturized energy storage module can be provided. [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 body in the energy storage module, viewed in the direction of the VV arrow. [Figure 6] This is a partially disassembled perspective view of the energy storage module according to Embodiment 2. [Figure 7] This is a partially disassembled perspective view of the energy storage module according to Embodiment 3. [Modes for carrying out the invention]

[0010] Each embodiment 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 second direction D2 with the plurality of electrode bodies 100 and electrically connects adjacent electrode bodies 100 to each other. The second direction D2 is perpendicular to the first direction D1.

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

[0014] Figure 5 is a cross-sectional view of the electrode body in the energy storage module of Figure 1, viewed in the direction of the VV arrow. As shown in Figure 5, each of the multiple electrode bodies 100 comprises multiple electrodes 110, 120 and a separator 130. In this embodiment, the electrode body 100 is, for example, an electrode body for a secondary battery such as a lithium-ion secondary battery.

[0015] As shown in Figure 5, the multiple electrodes 110, 120 are arranged in a line in the first direction D1. The multiple electrodes 110, 120 consist of multiple positive electrodes 110 and multiple negative electrodes 120.

[0016] Each positive electrode 110 is formed in a rectangular shape that is elongated in the second direction D2. Each positive electrode 110 has a positive electrode current collector foil 112 and a positive electrode active material layer 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 Figures 3 and 4) on which the positive electrode active material layer 114 is not provided. The positive electrode tab 112p protrudes toward one side in the second direction D2.

[0017] Each negative electrode 120 is formed in a rectangular shape that is elongated in the second direction D2. Each negative electrode 120 has a negative electrode current collector foil 122 and a negative electrode active material layer 124 provided on both sides of the negative electrode current collector foil 122. The negative electrode current collector foil 122 has a negative electrode tab 122n (see Figures 3 and 4) on which the negative electrode active material layer 124 is not provided. The negative electrode tab 122n protrudes toward the other side in the second direction D2.

[0018] 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 allow the permeation of ions. 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 of the electrodes 110 and 120. The separator 130 has a plurality of intervening portions 132a, a plurality of upper folding-back portions 132b, a plurality of lower folding-back portions 132c, and an outermost covering portion 132d.

[0020] Each intervening portion 132a intervenes between a pair of electrodes 110 and 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 upper folding-back 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 to each other. In the present embodiment, the upper folding-back portion 132b is disposed above the positive electrode 110.

[0022] Each lower folding-back portion 132c connects the lower end portion of the one intervening portion among the plurality of intervening portions 132a and the lower end portion of an intervening portion 132a adjacent to the one intervening portion on the other side in one direction among the plurality of intervening portions 132a to each other. In the present embodiment, the lower folding-back portion 132c is disposed below the negative electrode 120. In other words, the negative electrode 120 is disposed on the lower folding-back portion 132c. <00001​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 second direction D2. 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. 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] As shown in Figures 1 to 4, 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 third direction D3. The third direction D3 is perpendicular to both the first direction D1 and the second direction D2. The bottom wall portion 211 extends along the first direction D1 and the second direction D2. Viewed from the third direction D3, 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 circumferential end of the bottom wall portion 211 in a third direction D3, 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 second direction D2. The pair of second wall portions 214 are aligned in a second direction D2. 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. In this embodiment, the connecting conductive member 310 is exposed through two holes 215. These holes 215 may be arranged to be continuous with each other.

[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 portion 220 has at least electrical insulation on the surface facing the electrode body 100. The partition wall portion 220 is located between a plurality of adjacent electrode bodies 100 and partitions the housing space S of the case body 210. The case 200 according to this embodiment has a plurality of partition wall portions 220. The plurality of partition wall portions 220 includes a first partition wall portion 220A and a second partition wall portion 220B. The plurality of partition wall portions 220 may include three or more partition wall portions.

[0036] 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.

[0037] 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. 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 diagram. 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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).

[0044] 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.

[0045] 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.

[0046] 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, in addition to graphite.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] The first external conductive member 320A is aligned with the third electrode body 100C in the second direction D2 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 second direction D2 and is electrically connected to the second electrode body 100B.

[0056] Each external conductive member 320 has a third inner surface portion 321, an external connection surface portion 322, and an embedded end portion 323.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] Each connecting conductive member 310 and each external conductive member 320 is made of a metal such as stainless steel, aluminum, or copper. Furthermore, the method of partially embedding each connecting conductive member 310 and each external conductive member 320 in the circumferential side wall portion 212 (second wall portion 214) of the case body 210 is not particularly limited. For example, a resin composition as the material for the circumferential side wall portion 212 (second wall portion 214) of the case body 210 may be injection molded to cover a portion of each connecting conductive member 310 and each external conductive member 320.

[0061] 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.

[0062] 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.

[0063] As described above, the energy storage module 1 according to Embodiment 1 of the present disclosure comprises a plurality of electrode bodies 100, a case 200, and at least one connecting conductive member 310. The connecting conductive member 310 has a first end 311A, a second end 311B, a first inner surface portion 312A, and a second inner surface portion 312B. The first end 311A ​​is one end of the connecting conductive member 310 in the first direction D1 and is embedded in the case body 210. The second end 311B is the other end of the connecting conductive member 310 in the first direction D1 and is embedded in the case body 210. The first inner surface portion 312A is exposed in the first compartment S1 and is electrically connected to the first electrode body 100A housed in the first compartment S1 among the plurality of electrode bodies 100. The second inner surface portion 312B is exposed to the second compartment S2 and is electrically connected to the second electrode body 100B, which is housed in the second compartment S2 among the multiple electrode bodies 100.

[0064] According to the above configuration, the connecting conductive member 310 electrically connects the first electrode body 100A and the second electrode body 100B, while being at least partially embedded in the case body 210 in the first direction D1. Therefore, the energy storage module 1 can be miniaturized.

[0065] Furthermore, in Embodiment 1 of the present disclosure, the case body 210 has a hole 215 provided to expose a portion of the connecting conductive member 310 to the outside of the case body 210, and which is closed by the connecting conductive member 310. The connecting conductive member 310 further has a first outer surface portion 313A located on the opposite side of the first inner surface portion 312A and exposed to the outside of the case body 210 through the hole 215. The 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.

[0066] With the above configuration, since the pressure relief valve 314 is provided on the connecting conductive member 310, the safety of the energy storage module 1 can be further enhanced. In addition, compared to the case where the pressure relief valve is provided on the electrically insulating case body 210, the pressure relief valve can be easily provided on the energy storage module 1.

[0067] Furthermore, the energy storage module 1 according to Embodiment 1 of this disclosure further comprises an external conductive member 320. The external conductive member 320 is aligned in the second direction D2 with the third electrode body 100C, which is located at the outermost end in the first direction D1 among the plurality of electrode bodies 100, and is electrically connected to the third electrode body 100C. The external conductive member 320 has a third inner surface portion 321, an external connection surface portion 322, and a buried end portion 323. The third inner surface portion 321 is exposed to the housing space S and is electrically connected to the third electrode body 100C. The external connection surface portion 322 is exposed to the outside of the case body 210 in the first direction D1. The buried end portion 323 is the end opposite to the external connection surface portion 322 side in the first direction D1 and is embedded in the case body 210.

[0068] With the above configuration, the external connection surface 322 facilitates connection with other conductive members (for example, the external connection surface of another energy storage module) in the first direction D1. Furthermore, since the external conductive member 320 is partially embedded in the case body 210, the energy storage module 1 can be made smaller.

[0069] Furthermore, in Embodiment 1 of the present disclosure, the case body 210 has a bottom wall portion 211, a circumferential side wall portion 212, a lid 216, and a welded portion 217. The bottom wall portion 211 is made of a resin composition and is located on one side in a third direction D3. The third direction D3 is perpendicular to both the first direction D1 and the second direction D2. The circumferential side wall portion 212 is made of a resin composition and is integrally molded with the bottom wall portion 211, forming an opening OP that rises from the circumferential end of the bottom wall portion 211 in the third direction D3 and faces the opposite side from the bottom wall portion 211. The lid 216 closes the opening OP and at least the portion facing the circumferential side wall portion 212 is made of a resin composition. The welded portion 217 is formed by heat welding the lid 216 and the circumferential side wall portion 212 to each other.

[0070] With the above configuration, since both the case body 210 and the lid 216 are made of a resin composition, the welded portion 217 can be easily formed. Consequently, the opening OP can be easily sealed.

[0071] (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.

[0072] Figure 6 is a partially disassembled perspective view of the energy storage module according to Embodiment 2. As shown in Figure 6, 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.

[0073] The lid body portion 218 may have a similar configuration to the lid 216 in Embodiment 1. From the viewpoint of increasing rigidity, the lid body portion 218 is preferably a plate-shaped member including a metal plate. 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 wall 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).

[0074] 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.

[0075] (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.

[0076] Figure 7 is an exploded perspective view of a partially disassembled energy storage module according to Embodiment 3. As shown in Figure 7, 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.

[0077] The embodiments disclosed herein should be considered in all respects to be illustrative 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]

[0078] 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 1. Cover, 217. Welded part, 218, 218b. Cover body, 219. Gasket, 220. Partition, 220A. First partition, 220B. Second partition, 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, 311B. Second end, 312A. First inner surface, 312B. Second inner surface, 313A. First outer surface, 313B. Second outer surface, 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 connecting surface, 323. Embedded end, 324. Third outer surface, 400. Current collector, OP opening, S housing space, S1 first section, S2 second section, S3 third section.

Claims

1. A first electrode body and a second electrode body arranged in a first direction, A case for housing the first electrode and the second electrode, The device comprises a connecting conductive member that is aligned with the first electrode body and the second electrode body in a second direction perpendicular to the first direction and electrically connects the first electrode body and the second electrode body, The aforementioned case is, A case body having electrical insulation properties, surrounding the first electrode body and the second electrode body, It has an electrically insulating partition wall that is located between the first electrode body and the second electrode body and divides the housing space of the case body, The storage space of the case body is formed by the partition wall, which creates a first section and a second section adjacent to the first section via the partition wall. The connecting conductive member has a first end, a second end, a first inner surface portion, and a second inner surface portion. The first end is one end of the connecting conductive member in the first direction and is embedded in the case body. The second end is the other end of the connecting conductive member in the first direction, and is embedded in the case body. The first inner surface is exposed to the first compartment and electrically connected to the first electrode body housed in the first compartment. The second inner surface is exposed to the second compartment and is electrically connected to the second electrode body housed in the second compartment. The case body has a hole provided to expose a part of the connecting conductive member to the outside of the case body, and which is closed by the connecting conductive member. The connecting conductive member further has a first outer surface portion located on the opposite side of the first inner surface portion and exposed to the outside of the case body through the hole, The aforementioned connecting conductive member is provided with a pressure relief valve that can release the pressure on the first inner surface side to the first outer surface side, in this energy storage module.

2. A plurality of electrode bodies, including a first electrode body, a second electrode body, and a third electrode body that are aligned in a first direction toward each other, A case for housing the plurality of electrode bodies, A first connecting conductive member is arranged in a second direction perpendicular to the first direction, alongside the first electrode body and the second electrode body, and electrically connects the first electrode body and the second electrode body. In the second direction, the device comprises a second connecting conductive member that is aligned with the third electrode body and electrically connects the third electrode body to other electrode bodies from the plurality of electrode bodies that are different from the third electrode body, The aforementioned case is, A case body having electrical insulation properties and surrounding the plurality of electrode bodies, A first partition wall portion having electrical insulation properties and positioned between the first electrode body and the second electrode body to partition the housing space of the case body, It has an electrically insulating second partition wall that is located between the third electrode body and the other electrode bodies and partitions the housing space of the case body, The storage space of the case body is formed by the first partition wall, creating a first section and a second section adjacent to the first section via the first partition wall. The first connecting conductive member has a first end, a second end, a first inner surface portion, and a second inner surface portion. The first end is one end of the first connecting conductive member in the first direction and is embedded in the case body. The second end is the other end of the first connecting conductive member in the first direction, and is embedded in the case body. The first inner surface is exposed to the first compartment and electrically connected to the first electrode body housed in the first compartment. The second inner surface is exposed to the second compartment and is electrically connected to the second electrode body housed in the second compartment. The third electrode body is located at the very end of the plurality of electrode bodies in the first direction, The system further comprises an external conductive member that is aligned with the third electrode body in the second direction and electrically connected to the third electrode body, The external conductive member has a third inner surface portion, an external connection surface portion, and an embedded end portion. The third inner surface is exposed to the housing space and electrically connected to the third electrode body. The external connection surface is exposed to the outside of the case body in the first direction. The embedded end is the end opposite to the external connection surface in the first direction and is embedded in the case body of the energy storage module.

3. The aforementioned case body is It is made of a resin composition and has a bottom wall portion located on one side in a third direction that is perpendicular to both the first and second directions, 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 third direction, forming an opening that faces away from the bottom wall portion side, A lid that closes the opening and whose portion facing the peripheral wall is made of a resin composition, The energy storage module according to claim 1 or claim 2, having a welded portion formed by heat welding the lid and the peripheral side wall portion to each other.

4. The aforementioned case body is A bottom wall portion located on one side in a third direction perpendicular to both the first and second directions, A circumferential wall portion is integrally molded with the bottom wall portion and rises from the circumferential end of the bottom wall portion in the third direction, forming an opening that faces away from the bottom wall portion. It has a lid that closes the opening, The aforementioned lid is The lid body and, The energy storage module according to claim 1 or claim 2, further comprising a gasket sandwiched between the lid body and the peripheral side wall.

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