Energy storage module

Abstract

To provide a power storage module in which moisture permeability of a resin case is reduced.SOLUTION: A power storage module 1 includes a plurality of electrode assemblies 100 and a case 200. The case 200 includes a bottom portion 210, a peripheral sidewall portion 220, a lid portion 250, and at least one partition portion 260. The bottom portion 210 is located at one side of the electrode assemblies 100 in a second direction D2. The partition portion 260 is formed integrally with the bottom portion 210 and the peripheral sidewall portion 220. The partition portion 260 is located between the electrode assemblies 100 adjacent to each other. Each of the bottom portion 210, the peripheral sidewall portion 220, and the lid portion 250 includes a resin layer R and a barrier layer B. The resin layer R is made from a resin composition. The barrier layer B is superposed on the resin layer R. The barrier layer B has a lower moisture permeability than that of the resin layer R.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] The battery case disclosed in Patent Document 1 (JP 2019-106372 A) has a storage section in which a lower wall and multiple (e.g., three, four, or more) side walls are integrated to form an internal space, has an open surface facing the lower wall, and is provided with one or more (e.g., two, three, four, five, or more) partition walls within the space. This results in the storage section including multiple battery compartments separated by one or more partition walls disposed within the space. Each battery compartment can accommodate an electrode assembly. The battery case also includes a lid for closing the open surface of the storage section. The storage section is a molded product of a composition including a base polymer and an inorganic moisture absorbent dispersed in the base polymer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-106372 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 discloses a resin case capable of housing multiple electrode assemblies. However, because the case is made of resin, it has higher moisture permeability than a metal case. There is room for further improvement in reducing the moisture permeability of the case.

[0005] The present disclosure has been made in view of the above-mentioned problems, and aims to provide an electricity storage module in which the moisture permeability of the resin case is reduced. [Means for solving the problem]

[0006] An energy storage module according to the present disclosure includes a plurality of electrode assemblies and a case. The plurality of electrode assemblies are aligned in a first direction. The case houses the plurality of electrode assemblies. The case includes a bottom, a peripheral side wall, a lid, and at least one partition wall. The bottom is located on one side of the plurality of electrode assemblies in a second direction. The second direction is perpendicular to the first direction. The peripheral side wall rises from the outer peripheral edge of the bottom along the second direction. The peripheral side wall surrounds the plurality of electrode assemblies. The lid is located on the other side of the plurality of electrode assemblies in the second direction. The partition wall is integrally formed with the bottom and the peripheral side wall. The partition wall is located between adjacent plurality of electrode assemblies. The bottom, the peripheral side wall, and the lid each include a resin layer and a barrier layer. The resin layer is made of a resin composition. The barrier layer is laminated on the resin layer. The barrier layer has lower moisture permeability than the resin layer.

[0007] According to the above configuration, a barrier layer is disposed on each of the bottom, the peripheral sidewall, and the lid, along with the resin layer. This reduces the moisture permeability of the case in the energy storage module, even when the case is primarily composed of a resin layer. As a result, an energy storage module with a resin case having reduced moisture permeability is provided. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide an electricity storage module in which the moisture permeability of the resin case is reduced. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing an electricity storage module according to a first embodiment. [Figure 2] FIG. 2 is an exploded perspective view of a part of the electricity storage module according to the first embodiment. [Figure 3] 3 is a cross-sectional view of the energy storage module of FIG. 1, taken along the line III-III. [Figure 4] 4 is a cross-sectional view of the energy storage module of FIG. 1 as viewed in the direction of the arrows along line IV-IV. [Figure 5]2 is a cross-sectional view of an electrode body in the electricity storage module of FIG. 1, as viewed in the direction of the arrows along line VV. [Figure 6] 6A and 6B are cross-sectional views of the electricity storage module according to the second embodiment. [Figure 7] FIG. 10 is a cross-sectional view of an electricity storage module according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Each embodiment of the present disclosure will be described with reference to the drawings, in which the same or corresponding components are designated by the same reference numerals.

[0011] (Embodiment 1) Fig. 1 is a perspective view showing an energy storage module according to embodiment 1. Fig. 2 is an exploded perspective view in which the energy storage module according to embodiment 1 is partially disassembled. Fig. 3 is a cross-sectional view of the energy storage module of Fig. 1 as seen in the direction of the arrows III-III. Fig. 4 is a cross-sectional view of the energy storage module of Fig. 1 as seen in the direction of the arrows IV-IV.

[0012] As shown in Figures 1 to 4, an energy storage module 1 according to a first embodiment of the present disclosure includes a plurality of electrode assemblies 100 and a case 200. The plurality of electrode assemblies 100 are arranged in a first direction D1. A second direction D2, which will be described later, is a direction perpendicular to the first direction D1, and a third direction D3 is a direction perpendicular to both the first direction D1 and the second direction D2. The case 200 houses the plurality of electrode assemblies 100.

[0013] In this embodiment, the multiple electrode assemblies 100 include a first electrode assembly 100A, a second electrode assembly 100B, and a third electrode assembly 100C. The third electrode assembly 100C is located opposite the second electrode assembly 100B when viewed from the first electrode assembly 100A. The multiple electrode assemblies 100 may include four or more electrode assemblies.

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

[0015] 5, the plurality of electrodes 110, 120 are arranged to line up in a first direction D1. The plurality of electrodes 110, 120 includes 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. 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) on which 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 sides 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) on which 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 provides insulation 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 ions to pass through. As shown in Figure 5, the separator 130 is formed in a zigzag shape.

[0019] The separator 130 has a rectangular shape before being folded in a zigzag shape. The separator 130 is disposed between the electrodes 110, 120 while being folded in a zigzag shape. The separator 130 has a plurality of intervening portions 132a, a plurality of upper folded portions 132b, a plurality of lower folded portions 132c, and an outermost covering portion 132d.

[0020] Each intervening portion 132a is interposed between a pair of electrodes 110, 120 adjacent to each other in one direction. In other words, each intervening portion 132a has the function of insulating between the positive electrode 110 and the negative electrode 120. Each intervening portion 132a is formed of a rectangular region.

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

[0022] Each lower folded portion 132c connects the lower end of one of the plurality of intervening portions 132a to the lower end of another of the plurality of intervening portions 132a that is adjacent to the one intervening portion on the other side in one direction. In this embodiment, the lower folded portion 132c is disposed below the negative electrode 120. In other words, the negative electrode 120 is disposed on the lower folded portion 132c.

[0023] The outermost covering portion 132d collectively covers the upper folded portions 132b and the lower folded portions 132c. More specifically, the outermost covering portion 132d collectively covers all of the electrodes 110, 120, all of the intervening portions 132a, all of the upper folded portions 132b, and all of the lower folded portions 132c while being wound around a central axis parallel to the third direction D3. The end 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 132e of the outermost covering portion 132d is provided below the electrodes 110, 120. The peripheral surfaces 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 plurality of electrodes 110 and 120 and separator 130 may be in direct contact with the case 200 .

[0024] 1 to 4, the case 200 includes a bottom 210, a peripheral side wall 220, a lid 250, and at least one partition 260. Each of the bottom 210, the peripheral side wall 220, and the lid 250 includes a resin layer R and a barrier layer B.

[0025] The resin layer R has electrical insulation properties. The resin layer R is made of a resin composition. The barrier layer B is laminated on the resin layer R. The barrier layer B has lower moisture permeability than the resin layer R. Details of the resin layer R and the barrier layer B will be described later.

[0026] The bottom portion 210 is located on one side of the plurality of electrode assemblies 100 in the second direction D2. The bottom portion 210 extends along the first direction D1 and the third direction D3. When viewed from the second direction D2, the bottom portion 210 has a rectangular outer shape.

[0027] The bottom 210 includes a first bottom resin layer 211 made of a first resin composition as the resin layer R, a bottom barrier layer 212 as the barrier layer B, and a second bottom resin layer 213 made of a third resin composition. The second resin composition will be described later.

[0028] The bottom barrier layer 212 is disposed on the outer side of the case 200 when viewed from the first bottom resin layer 211. When viewed from the second direction D2, the bottom barrier layer 212 is disposed so as to overlap the entire first bottom resin layer 211. The bottom barrier layer 212 is bonded to the first bottom resin layer 211 via the second bottom resin layer 213.

[0029] The second bottom resin layer 213 is joined to the first bottom resin layer 211 by thermal welding. The second bottom resin layer 213 and the first bottom resin layer 211 may be welded over the entire contact surface thereof, or only a portion of the contact surface thereof. The second bottom resin layer 213 may be welded only near the outer peripheral edge of the first bottom resin layer 211 when viewed from the second direction D2.

[0030] The peripheral side wall 220 stands upright in the second direction D2 from the outer peripheral edge of the bottom 210. The peripheral side wall 220 surrounds the multiple electrode bodies 100. The peripheral side wall 220 forms an opening OP facing away from the bottom 210.

[0031] The peripheral side wall portion 220 has a pair of first wall portions 230 and a pair of second wall portions 240. The pair of first wall portions 230 are aligned in the first direction D1. The pair of first wall portions 230 extend along the third direction D3. The pair of second wall portions 240 are aligned in the third direction D3. The pair of second wall portions 240 extend along the first direction D1.

[0032] The peripheral side wall portion 220 includes a first peripheral side resin layer 221 made of a first resin composition as a resin layer R, a peripheral side barrier layer 222 as a barrier layer B, and a second peripheral side resin layer 223 made of a second resin composition.

[0033] The circumferential barrier layer 222 is disposed on the outer side of the case 200 when viewed from the first circumferential resin layer 221. When viewed from the first direction D1 and the third direction D3, the circumferential barrier layer 222 is disposed so as to overlap the entire first circumferential resin layer 221. The circumferential barrier layer 222 is bonded to the first circumferential resin layer 221 via the second circumferential resin layer 223.

[0034] The second circumferential resin layer 223 is joined to the first circumferential resin layer 221 by thermal welding. The second circumferential resin layer 223 and the first circumferential resin layer 221 may be welded over the entire contact surface thereof, or only a portion of the contact surface thereof. For example, when viewed from the first direction D1, the second circumferential resin layer 223 and the first circumferential resin layer 221 may be thermally welded to each other only near the peripheral ends of the pair of first wall portions 230. When viewed from the third direction D3, the second circumferential resin layer 223 and the first circumferential resin layer 221 may be thermally welded to each other only near the peripheral ends of the pair of second wall portions 240.

[0035] The lid portion 250 is located on the other side of the plurality of electrode assemblies 100 in the second direction D2. The lid portion 250 closes the opening OP. The lid portion 250 has, for example, a film-like outer shape.

[0036] The lid portion 250 includes a lid resin layer 251 made of the fourth resin composition as the resin layer R, and a lid barrier layer 252 as the barrier layer B.

[0037] The lid resin layer 251 is bonded to the first periphery side resin layer 221 by heat welding or the like. The lid barrier layer 252 is disposed on the outer side of the case 200 when viewed from the lid resin layer 251. The lid barrier layer 252 is bonded to the first periphery side resin layer 221 via the lid resin layer 251.

[0038] The partition wall portions 260 are located between adjacent electrode bodies 100. The partition wall portions 260 divide the storage space S of the case 200. The case 200 according to this embodiment has multiple partition wall portions 260. The multiple partition wall portions 260 include a first partition wall portion 260A and a second partition wall portion 260B. The multiple partition wall portions 260 may include three or more partition wall portions.

[0039] A first partition wall portion 260A defines a first compartment S1 and a second compartment S2 in the storage space S of the case 200. A second partition wall portion 260B defines a first compartment S1 and a third compartment S3 in the storage space S. The third compartment S3 is located opposite the second compartment S2 when viewed from the first compartment S1.

[0040] The first electrode body 100A is accommodated in the first compartment S1. The second electrode body 100B is accommodated in the second compartment S2. The third electrode body 100C is accommodated in the third compartment. An electrolyte solution is poured into the accommodation space S (first compartment S1, second compartment S2, third compartment S3). The electrolyte solution is not shown. The method for pouring the electrolyte solution is not particularly limited. The electrolyte solution may be poured through the opening OP before the opening OP is closed by the lid portion 250.

[0041] The partition wall portion 260 is made of a first resin composition. The partition wall portion 260 is integrally molded with the bottom portion 210 and the peripheral side wall portion 220. Specifically, the first bottom resin layer 211, the first peripheral side resin layer 221, and the partition wall portion 260 are integrally molded with one another. The partition wall portion 260 and the lid resin layer 251 may or may not be joined to one another by thermal welding.

[0042] In this embodiment, the above-mentioned "integrally molded" method may include a method in which each component is molded and joined simultaneously in one step by a known method such as injection molding, or a method in which multiple components are molded separately and then joined together by a known joining method such as welding, adhesion, or the like.

[0043] Here, the first resin composition that can constitute the first bottom resin layer 211, the first peripheral resin layer 221, and the partition wall portion 260 in this embodiment will be described.

[0044] The first resin composition may contain, 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), fluorine-based resin, a mixture thereof, an alloy thereof, or a copolymer thereof, but the base polymer is not limited to these.

[0045] The first resin composition may contain polyolefin, liquid crystal polymer, or fluororesin as a base polymer. The polyolefin may contain high density polyethylene (HDPE). High density polyethylene, liquid crystal polymer, or fluororesin has a relatively low water vapor permeability. Therefore, case 200 mainly made of a resin composition containing these has relatively high moisture permeability resistance.

[0046] The liquid crystal polymer may contain structural units derived from an oligomer of hydroxybenzoic acid. The liquid crystal polymer may further contain, in addition to the oligomer of hydroxybenzoic acid, two or more selected from the group consisting of 2,6-hydroxynaphthoic acid (HNA), terephthalic acid (TPA), isophthalic acid (IPA), hydroquinone (HQ), biphenol (BP), polyethylene terephthalate (PET), and polyethylene naphthalate (PEN), copolymerized with the oligomer of hydroxybenzoic acid (HBA).

[0047] Examples of fluororesins include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), and mixtures or copolymers thereof. Fluororesins are hydrophobic. Therefore, 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% by weight to about 10% by weight, or about 5% by weight to about 10% by weight of the fluororesin, based on the total weight of the resin composition. When the content of the fluororesin is within the above range, a molded article made from the first resin composition is considered to have the effect of blocking moisture from the surface of the molded article that comes into contact with the outside air.

[0048] The first resin composition may further contain an inorganic moisture absorbent or graphite from the viewpoint of suppressing water vapor transmission rate. In addition, the resin composition may further contain a substance other than graphite that is known as an existing moisture barrier substance.

[0049] In this embodiment, the bottom barrier layer 212 and the second bottom resin layer 213, the peripheral barrier layer 222 and the second peripheral resin layer 223, and the lid resin layer 251 and the lid barrier layer 252 are made of so-called laminate films.

[0050] The bottom barrier layer 212, the peripheral barrier layer 222, and the lid barrier layer 252 are made of a metal such as aluminum. In this embodiment, the thickness of each of the bottom barrier layer 212, the peripheral barrier layer 222, and the lid barrier layer 252 is preferably, for example, 100 μm or less from the viewpoint of formability.

[0051] The thicknesses of the second bottom resin layer 213, the second periphery-side resin layer 223, and the lid resin layer 251 are all thinner than the thicknesses of the first bottom resin layer 211 and the first periphery-side resin layer 221. The thicknesses of the second bottom resin layer 213, the second periphery-side resin layer 223, and the lid resin layer 251 may be, for example, 50 μm or less.

[0052] The specific compositions of the third resin composition constituting the second bottom resin layer 213, the second resin composition constituting the second peripheral resin layer 223, and the fourth resin composition constituting the lid resin layer 251 are not particularly limited. The base polymer contained in the second, third, and fourth resin compositions is preferably the same as the base polymer contained in the first resin composition. This makes it easier to heat-weld the second bottom resin layer 213, the second peripheral resin layer 223, and the lid resin layer 251 to other resin layers of the case 200 made of the first resin composition. From the perspective of making heat-welding easier, the base polymer of these compositions is also preferably polyethylene or polypropylene.

[0053] The energy storage module 1 according to the first embodiment of the present disclosure includes a plurality of conductive members 300. Each conductive member 300 is aligned with a plurality of electrode assemblies 100 in the third direction D3. Each conductive member 300 may electrically connect a plurality of electrode assemblies 100 adjacent to each other in the first direction D1. The plurality of conductive members 300 are provided so as to be exposed to the storage space S. The plurality of conductive members 300 are partially embedded in the case 200. The conductive members 300 are arranged so as not to come into contact with each barrier layer. The conductive members 300 may be exposed to the outside of the case 200.

[0054] The energy storage module 1 according to the first embodiment of the present disclosure further includes a plurality of current collecting members 400. The plurality of current collecting members 400 are located on both sides of each of the plurality of electrode assemblies 100 in the third direction D3. Each current collecting member 400 is joined to the positive electrode tab 112p or the negative electrode tab 122n by welding. Each current collecting member 400 is further joined to the conductive member 300. This electrically connects the conductive member 300 and the electrode assembly 100. Note that the positive electrode tab 112p or the negative electrode tab 122n may be directly connected to the conductive member 300 by welding.

[0055] As described above, in the energy storage module 1 according to the first embodiment of the present disclosure, the bottom portion 210, the peripheral side wall portion 220, and the lid portion 250 each have a resin layer R and a barrier layer B. The resin layer R is made of a resin composition. The barrier layer B is laminated on the resin layer R. The barrier layer B has lower moisture permeability than the resin layer R.

[0056] According to the above configuration, the barrier layer B is disposed together with the resin layer R on each of the bottom 210, the peripheral side wall 220, and the lid 250. This makes it possible to reduce the moisture permeability of the case 200 in the energy storage module 1 even when the case 200 is mainly composed of the resin layer R. Consequently, an energy storage module 1 is provided in which the moisture permeability of the resin case is reduced.

[0057] Furthermore, in the first embodiment of the present disclosure, the bottom portion 210 includes a first bottom resin layer 211 made of a first resin composition as the resin layer R, and a bottom barrier layer 212 as the barrier layer B. The peripheral side wall portion 220 includes a first peripheral side resin layer 221 made of the first resin composition as the resin layer R, and a peripheral side barrier layer 222 as the barrier layer B. The partition portion 260 is made of the first resin composition. The first bottom resin layer 211, the first peripheral side resin layer 221, and the partition portion 260 are integrally molded with one another.

[0058] According to the above configuration, the first bottom resin layer 211, the first peripheral side resin layer 221, and the partition portion 260 are all made of the first resin composition and are molded integrally with each other, thereby reducing the manufacturing cost of the case 200.

[0059] Furthermore, in the first embodiment of the present disclosure, the peripheral side wall portion 220 further includes a second peripheral side resin layer 223 made of a second resin composition. The peripheral side barrier layer 222 is disposed on the outer side of the case 200 as viewed from the first peripheral side resin layer 221. The peripheral side barrier layer 222 is bonded to the first peripheral side resin layer 221 via the second peripheral side resin layer 223.

[0060] According to the above configuration, the circumferential barrier layer 222 can be easily disposed on the circumferential wall portion 220. For example, by welding a laminate film including a resin sheet and a barrier sheet to the outside of the first circumferential resin layer 221, the resin sheet and the barrier sheet can be disposed as the second circumferential resin layer 223 and the circumferential barrier layer 222.

[0061] Furthermore, in the first embodiment of the present disclosure, the bottom portion 210 further includes a second bottom resin layer 213 made of a third resin composition. The bottom barrier layer 212 is disposed on the outer side of the case 200 as viewed from the first bottom resin layer 211. The bottom barrier layer 212 is bonded to the first bottom resin layer 211 via the second bottom resin layer 213.

[0062] According to the above configuration, the bottom barrier layer 212 can be easily arranged on the bottom 210. For example, by welding a laminate film including a resin sheet and a barrier sheet to the outside of the first bottom resin layer 211, the resin sheet and the barrier sheet can be arranged as the second bottom resin layer 213 and the bottom barrier layer 212.

[0063] (Embodiment 2) Hereinafter, a description will be given of an energy storage module according to a second embodiment of the present disclosure. The energy storage module according to the second embodiment of the present disclosure differs from the energy storage module 1 according to the first embodiment of the present disclosure mainly in the configuration of the peripheral side wall portion. Therefore, the description of the configuration and effects of the energy storage module according to the second embodiment of the present disclosure that are similar to those of the first embodiment will not be repeated.

[0064] Fig. 6A is a cross-sectional view of the energy storage module according to embodiment 2 as seen from one direction. Fig. 6B is a cross-sectional view of the energy storage module according to embodiment 2 as seen from another direction. Figs. 6A and 6B show the energy storage module in a cross-sectional view similar to the cross-section of the energy storage module 1 according to embodiment 1 shown in Figs. 3 and 4, respectively.

[0065] 6A and 6B, in the energy storage module 1a according to the second embodiment of the present disclosure, the peripheral barrier layer 222a is embedded in the first peripheral resin layer 221a so as not to be exposed from the peripheral wall portion 220a, which makes it easy to ensure electrical insulation on the outer surface of the peripheral wall portion 220a.

[0066] The first circumferential resin layer 221a is formed, for example, by injection molding the second resin composition so as to surround the circumferential barrier layer 222a. In this embodiment, the circumferential barrier layer 222a may be a plate-shaped member.

[0067] (Embodiment 3) Hereinafter, an energy storage module according to a third embodiment of the present disclosure will be described. The energy storage module according to the third embodiment of the present disclosure differs from the energy storage module 1a according to the second embodiment of the present disclosure mainly in the configuration of the bottom. Therefore, the description of the configuration and effects of the energy storage module according to the third embodiment of the present disclosure that are similar to those of the second embodiment will not be repeated.

[0068] Fig. 7 is a cross-sectional view of the energy storage module according to embodiment 3. In Fig. 7, the energy storage module is shown in a cross-sectional view similar to the cross-section of the energy storage module 1a according to embodiment 2 shown in Fig. 6A.

[0069] 7, in the energy storage module 1b according to the third embodiment of the present disclosure, the bottom barrier layer 212b is embedded in the first bottom resin layer 211b so as not to be exposed from the bottom portion 210b, which makes it easier to ensure electrical insulation on the outer surface of the bottom portion 210b.

[0070] The first bottom resin layer 211b is formed, for example, by injection molding the third resin composition so as to surround the bottom barrier layer 212b. In this embodiment, the bottom barrier layer 212b may be a plate-shaped member. Furthermore, the peripheral barrier layer 222b may extend upright from the outer peripheral edge of the bottom barrier layer 212b when viewed from the second direction D2.

[0071] The embodiments disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present invention is defined by the claims rather than the above description of the embodiments, and further includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0072] 1, 1a, 1b Energy storage module, 100 Electrode body, 100A First electrode body, 100B Second electrode body, 100C Third electrode body, 110 Positive electrode, 112 Positive current collector foil, 112p Positive electrode tab, 114 Positive electrode active material layer, 120 Negative electrode, 122 Negative current collector foil, 122n Negative electrode tab, 124 Negative electrode active material layer, 130 Separator, 132a Interposition portion, 132b Upper folded portion, 132c Lower folded portion, 132d Outermost coating portion, 132e End, 200 Case, 210, 210b Bottom portion, 211, 211b First bottom resin layer, 212, 212b Bottom barrier layer, 213 Second bottom resin layer, 220, 220a Peripheral wall portion, 221, 221a first peripheral resin layer, 222, 222a, 222b peripheral barrier layer, 223 second peripheral resin layer, 230 first wall portion, 240 second wall portion, 250 lid portion, 251 lid resin layer, 252 lid barrier layer, 260 partition portion, 260A first partition portion, 260B second partition portion, 300 conductive member, 400 current collecting member, B barrier layer, OP opening, R resin layer, S storage space, S1 first compartment, S2 second compartment, S3 third compartment.

Claims

1. A plurality of electrode bodies arranged in a first direction; a case for accommodating the plurality of electrode bodies; The case is a bottom portion located on one side of the plurality of electrode bodies in a second direction perpendicular to the first direction; a peripheral side wall portion that stands up from an outer peripheral edge of the bottom portion along the second direction and surrounds the plurality of electrode bodies; a lid portion located on the other side of the plurality of electrode bodies in the second direction; at least one partition wall portion that is integrally formed with the bottom portion and the peripheral side wall portion and is positioned between the plurality of electrode bodies that are adjacent to each other; each of the bottom portion, the peripheral side wall portion, and the lid portion has a resin layer made of a resin composition, and a barrier layer laminated on the resin layer and having lower moisture permeability than the resin layer; the bottom portion includes a first bottom resin layer made of a first resin composition as the resin layer and a bottom barrier layer as the barrier layer, the peripheral wall portion includes a first peripheral resin layer made of the first resin composition as the resin layer, and a peripheral barrier layer as the barrier layer, the partition wall is made of the first resin composition, the first bottom resin layer, the first peripheral resin layer, and the partition wall portion are integrally molded with one another, the bottom further includes a second bottom resin layer made of a third resin composition; the bottom barrier layer is disposed on the outer side of the case as viewed from the first bottom resin layer, the bottom barrier layer is bonded to the first bottom resin layer via the second bottom resin layer; the bottom barrier layer is located on the outer surface side of the bottom portion, the peripheral barrier layer and the bottom barrier layer are spaced apart from each other; Each of the plurality of electrode assemblies includes a plurality of positive electrodes, a plurality of negative electrodes, and a separator, In each of the plurality of electrode bodies, the plurality of positive electrodes, the plurality of negative electrodes, and the separator are stacked on top of each other in the first direction.

2. the peripheral side wall portion further includes a second peripheral side resin layer made of a second resin composition, the peripheral barrier layer is disposed on the outer side of the case as viewed from the first peripheral resin layer, the peripheral barrier layer is bonded to the first peripheral resin layer via the second peripheral resin layer, The energy storage module according to claim 1 , wherein the peripheral barrier layer is located on an outer surface side of the peripheral wall portion.

3. The energy storage module according to claim 1 , wherein the peripheral barrier layer is embedded in the first peripheral resin layer so as not to be exposed from the peripheral wall portion.

4. the lid portion includes a lid resin layer made of a fourth resin composition as the resin layer and a lid barrier layer as the barrier layer, the lid resin layer is bonded to the first peripheral resin layer, The energy storage module according to claim 1 , wherein the lid barrier layer is bonded to the first peripheral resin layer via the lid resin layer and is located on the outer surface side of the lid portion.

Images