JP2019079677A - Power storage module - Google Patents

Abstract

To provide a power storage module capable of restraining deformation of termination electrode at the time of internal pressure rise.SOLUTION: A power storage module 4 includes an electrode laminate 11 laminating multiple bipolar electrodes 14 via separators 13, and a sealed body 12 provided on the lateral face 11a of the electrode laminate 11, and sealing between the bipolar electrodes 14 adjoining in the lamination direction. At the lamination ends of the electrode laminate 11, termination electrodes 18, 19 having an electrode plate 15, where one of the positive electrode 16 and the negative electrode 17 is formed on the surface directing the inside in the lamination direction, are placed. The sealed body 12 has a first resin part 21A coupled to a marginal part 15c of the electrode plate 15 in the bipolar electrode 14, and second resin parts 21B, 21C coupled to the marginal part 15c of the electrode plate 15 in the termination electrodes 18, 19. Tensile strength of a second resin material composing the second resin parts 21B, 21C is larger than that of the first resin material composing the first resin part 21A.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a storage module.

  As a conventional storage module, there is known a so-called bipolar storage module including a bipolar electrode in which a positive electrode is formed on one surface of an electrode plate and a negative electrode is formed on the other surface (see Patent Document 1). The storage module includes an electrode stack in which a plurality of bipolar electrodes are stacked via a separator. The sealing body which seals between the bipolar electrodes which adjoin in the lamination direction is provided in the side of an electrode laminated body. An electrolyte is accommodated in an internal space formed between the bipolar electrodes by the sealing body.

JP, 2011-204386, A

  In the power storage module as described above, the internal pressure of the internal space may increase depending on the use conditions and the like. Even when the internal pressure rises, in the intermediate layer of the electrode stack, the load due to the internal pressure is canceled between the internal spaces adjacent in the stacking direction. In addition, since the internal space itself is a slight space, deformation of the electrode is relatively difficult to occur. On the other hand, unlike the middle layer, the load due to the internal pressure of the inner space is not canceled at the electrode located at the lamination end of the electrode lamination (hereinafter referred to as the terminal electrode). For this reason, it is conceivable that the terminal electrode deforms to the outside in the stacking direction when the internal pressure rises.

  When the end electrode is deformed, the seal is excessively stressed, and the seal may be broken or a gap may be generated between the seal and the end electrode. The breakage of the sealing body and the formation of the gap between the sealing body and the terminal electrode may cause leakage of the electrolyte to the outside of the electrode stack. Therefore, a technique for suppressing the deformation of the terminal electrode when the internal pressure rises is desired.

  The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a storage module capable of suppressing deformation of a terminal electrode at the time of increase in internal pressure.

  An electricity storage module according to one aspect of the present invention includes an electrode stack body in which a plurality of bipolar electrodes are stacked via a separator, and a seal that is provided on the side surface of the electrode stack body and seals between bipolar electrodes adjacent in the stacking direction. The bipolar electrode has an electrode plate having a positive electrode formed on one side and a negative electrode formed on the other side, and the laminated end of the electrode laminate has a surface facing inward in the laminating direction. A termination electrode having an electrode plate on which one of a positive electrode and a negative electrode is formed is disposed, and the sealing body includes a first resin portion bonded to an edge portion of the electrode plate in the bipolar electrode and an edge of the electrode plate in the termination electrode And a second resin part bonded to the part, wherein the tensile strength of the second resin material forming the second resin part is greater than the tensile strength of the first resin material forming the first resin part.

  In this storage module, the tensile strength of the second resin material constituting the second resin portion bonded to the edge of the electrode plate in the terminal electrode constitutes the first resin portion bonded to the edge of the electrode plate in the bipolar electrode Greater than the tensile strength of the first resin material. Thereby, when the internal pressure rises, stress acting on the terminal electrode can be suitably received by the second resin portion, and deformation of the terminal electrode when the internal pressure rises can be suppressed. By suppressing the deformation of the terminal electrode, it is possible to suppress the breakage of the second resin portion and the formation of the gap between the second resin portion and the terminal electrode, and to prevent the leakage of the electrolytic solution to the outside of the electrode stack.

  The Young's modulus of the second resin material may be larger than the Young's modulus of the first resin material. In this case, the deformation of the terminal electrode at the time of the rise of the internal pressure can be effectively suppressed.

  The second resin material may be polypropylene. In this case, the deformation of the terminal electrode when the internal pressure rises can be suppressed more effectively.

  The second resin material may be oriented polypropylene. In this case, the deformation of the terminal electrode at the time of the rise of the internal pressure can be suppressed more effectively.

  The second resin material may be biaxially oriented polypropylene. In this case, it is possible to more effectively suppress the deformation of the terminal electrode when the internal pressure rises.

  The first resin material may be non-oriented polypropylene. In this case, the above-described effect of suppressing deformation of the terminal electrode at the time of increase of the internal pressure is suitably exerted.

  The bonding surface of the terminal electrode to the second resin portion of the electrode plate may be a roughened plating surface. In this case, the bonding strength between the electrode plate and the second resin portion can be improved by the roughened plating surface. Therefore, the formation of the gap between the second resin portion and the termination electrode can be further suitably suppressed.

  According to the present invention, it is possible to suppress the deformation of the terminal electrode when the internal pressure rises.

It is a schematic sectional drawing which shows one Embodiment of an electrical storage apparatus. It is a schematic sectional drawing which shows one Embodiment of an electrical storage module. It is a principal part expanded sectional view showing a situation of a termination electrode at the side of a negative electrode at the time of internal pressure rise in a storage module concerning a comparative example. It is a principal part expanded sectional view which shows the mode of the termination electrode of the positive electrode side at the time of internal pressure rise in the electrical storage module which concerns on a comparative example.

Hereinafter, with reference to the drawings, a preferred embodiment of the storage module will be described in detail.
[Configuration of power storage device]

  FIG. 1 is a schematic cross-sectional view showing an embodiment of a power storage device. The storage device 1 is used, for example, as a battery of various vehicles such as a forklift, a hybrid car, and an electric car. The storage device 1 includes a storage module stack 2 in which a plurality of storage modules 4 are stacked, and a restraint member 3 for applying a restraint load to the storage module stack 2 in the stacking direction.

  The storage module stack 2 includes a plurality (three in the present embodiment) of storage modules 4 and a plurality (four in the present embodiment) of conductive plates 5. The storage module 4 is a bipolar battery provided with a bipolar electrode 14 described later. The storage module 4 has, for example, a rectangular shape when viewed from the stacking direction. The storage module 4 is, for example, a nickel hydrogen secondary battery, a secondary battery such as a lithium ion secondary battery, or an electric double layer capacitor. The following description exemplifies a nickel-hydrogen secondary battery.

  In the storage module stack 2, the storage modules 4, 4 adjacent to each other in the stacking direction are electrically connected via the conductive plate 5. The conductive plates 5 are respectively disposed between the storage modules 4 4 adjacent to each other in the stacking direction and on the outer side of the storage module 4 located at the stacking end. The positive electrode terminal 6 is connected to one of the conductive plates 5 disposed on the outer side of the storage module 4 located at the lamination end. The negative electrode terminal 7 is connected to the other conductive plate 5 disposed outside the power storage module 4 located at the stacking end. The positive electrode terminal 6 and the negative electrode terminal 7 are, for example, drawn out from the edge of the conductive plate 5 in the direction perpendicular to the stacking direction. Charging and discharging of the power storage device 1 are performed by the positive electrode terminal 6 and the negative electrode terminal 7.

  Inside each conductive plate 5, a plurality of flow paths 5a for circulating a refrigerant such as air are provided. Each flow path 5 a extends, for example, in a direction perpendicular to the stacking direction and the drawing direction of the positive electrode terminal 6 and the negative electrode terminal 7. In addition to the function as a connecting member for electrically connecting the storage modules 4 and 4 to each other, the conductive plate 5 dissipates heat generated by the storage module 4 by circulating the refrigerant through the flow paths 5a. It also has the function of In the example of FIG. 1, the area of the conductive plate 5 viewed from the stacking direction is smaller than the area of the storage module 4, but from the viewpoint of improvement of heat dissipation, the area of the conductive plate 5 is the storage module It may be the same as the area 4 or may be larger than the area of the storage module 4.

  The restraint member 3 includes a pair of end plates 8 and 8 sandwiching the storage module stack 2 in the stacking direction, and a fastening bolt 9 and a nut 10 for fastening the end plates 8 and 8 to each other. The end plate 8 is a rectangular metal plate having an area slightly larger than the areas of the storage module 4 and the conductive plate 5 as viewed in the stacking direction. A film F having electrical insulation is provided on the inner side surface (the surface on the side of the storage module stack 2) of the end plate 8, and the end plate 8 and the conductive plate 5 are electrically insulated. .

At the edge of the end plate 8, an insertion hole 8 a is provided at a position outside the power storage module stack 2. The fastening bolt 9 is passed from the insertion hole 8a of one end plate 8 toward the insertion hole 8a of the other end plate 8, and the tip portion of the fastening bolt 9 protrudes from the insertion hole 8a of the other end plate 8 , The nut 10 is screwed. Thus, the storage module 4 and the conductive plate 5 are sandwiched by the end plates 8 and 8 to be unitized as the storage module stack 2 and a restraint load is applied to the storage module stack 2 in the stacking direction. .
[Configuration of storage module]

  Next, the configuration of the storage module 4 will be described. FIG. 2 is a schematic cross-sectional view showing an embodiment of a storage module. The storage module 4 includes an electrode stack 11 and a sealing body 12 made of resin that seals the electrode stack 11.

  The electrode stack 11 is configured by stacking a plurality of bipolar electrodes 14 via a separator 13. In the present embodiment, the stacking direction of the electrode stack 11 and the stacking direction of the storage module stack 2 coincide with each other. The electrode stack 11 has side surfaces 11 a extending in the stacking direction. The bipolar electrode 14 includes an electrode plate 15, a positive electrode 16 provided on one surface 15 a of the electrode plate 15, and a negative electrode 17 provided on the other surface 15 b of the electrode plate 15. The positive electrode 16 is a positive electrode active material layer formed by coating a positive electrode active material. The negative electrode 17 is a negative electrode active material layer formed by coating a negative electrode active material. In the electrode stack 11, the positive electrode 16 of one bipolar electrode 14 faces the negative electrode 17 of one bipolar electrode 14 adjacent in the stacking direction across the separator 13. In the electrode stack 11, the negative electrode 17 of one bipolar electrode 14 faces the positive electrode 16 of the other bipolar electrode 14 adjacent in the stacking direction across the separator 13.

  In the electrode stack 11, the negative electrode termination electrode 18 is disposed at one end (one of the stack ends) in the stacking direction. In addition, the positive electrode termination electrode 19 is disposed at the other end (the other lamination end) in the lamination direction. The negative electrode terminal electrode 18 includes an electrode plate 15 and a negative electrode 17 provided on the other surface (a surface facing inward in the stacking direction) 15 b of the electrode plate 15. The negative electrode 17 of the negative electrode terminal electrode 18 faces the positive electrode 16 of the bipolar electrode 14 at one end in the stacking direction via the separator 13. One conductive plate 5 adjacent to the storage module 4 is in contact with one surface 15 a of the electrode plate 15 of the negative electrode terminal electrode 18. The positive electrode termination electrode 19 includes an electrode plate 15 and a positive electrode 16 provided on one surface (a surface facing inward in the stacking direction) 15 a of the electrode plate 15. The other conductive plate 5 adjacent to the storage module 4 is in contact with the other surface 15 b of the electrode plate 15 of the positive electrode terminal electrode 19. The positive electrode 16 of the positive electrode terminal electrode 19 is opposed to the negative electrode 17 of the bipolar electrode 14 at the other end in the stacking direction via the separator 13.

  The electrode plate 15 is made of, for example, a metal foil made of nickel or a nickel-plated steel plate, and has a rectangular shape. The edge 15 c of the electrode plate 15 is an uncoated region on which the positive electrode active material and the negative electrode active material are not applied. As a positive electrode active material which comprises the positive electrode 16, nickel hydroxide is mentioned, for example. As a negative electrode active material which comprises the negative electrode 17, a hydrogen storage alloy is mentioned, for example. In the present embodiment, the formation region of the negative electrode 17 on the other surface 15 b of the electrode plate 15 is one size larger than the formation region of the positive electrode 16 on the one surface 15 a of the electrode plate 15.

  The separator 13 is formed in, for example, a sheet shape. Examples of the separator 13 include porous films made of polyolefin resins such as polyethylene (PE) and polypropylene (PP), and woven or non-woven fabrics made of polypropylene, polyethylene terephthalate (PET), methyl cellulose and the like. The separator 13 may be reinforced with a vinylidene fluoride resin compound. The separator 13 is not limited to a sheet but may be formed in a bag.

  The sealing body 12 is formed in, for example, a rectangular cylindrical shape by an insulating resin. The sealing body 12 is configured to hold the edge 15 c of the electrode plate 15 on the side surface 11 a of the electrode stack 11 extending in the stacking direction and to surround the side surface 11 a. The sealing body 12 is provided with a plurality of primary sealing bodies 21 provided along the edge 15 c of each electrode plate 15 and a secondary sealing provided so as to surround the entire primary sealing body 21 from the outside. It is comprised by the stop body 22. FIG. The primary sealing body 21 is formed, for example, by injection molding of a resin, and is firmly bonded to the edge 15 c by welding using ultrasonic waves or heat.

The secondary sealing body 22 is formed, for example, by injection molding of a resin, and extends over the entire length in the stacking direction of the electrode stack 11. The secondary sealing body 22 is made of, for example, modified polyphenylene ether. The secondary sealing body 22 is welded to the outer surface of the primary sealing body 21 by, for example, heat at the time of injection molding, and seals between the bipolar electrodes 14 adjacent in the stacking direction. Thus, an internal space V is formed between the bipolar electrodes 14 and 14 adjacent in the stacking direction. Further, the secondary sealing body 22 seals between the negative electrode terminal electrode 18 and the positive electrode terminal electrode 19 and the bipolar electrode 14. Thus, an internal space V is formed between the negative electrode termination electrode 18 and the positive electrode termination electrode 19 and the bipolar electrode 14. In these internal spaces V, for example, an electrolytic solution E composed of an alkaline solution such as a potassium hydroxide aqueous solution is accommodated.
[Detailed Configuration of Primary Sealed Body]

  Next, the above-described primary sealing body 21 will be described in more detail. The primary sealing body 21 includes a first resin portion 21A coupled to the edge 15c of the electrode plate 15 of the bipolar electrode 14 and a second resin portion 21B coupled to the edge 15c of the electrode plate 15 of the negative electrode termination electrode 18; And a second resin portion 21C coupled to the edge portion 15c of the electrode plate 15 of the positive electrode terminal electrode 19.

  The first resin portion 21 </ b> A is continuously provided over all the sides of the electrode plate 15 at the edge portion 15 c on the side of the one surface 15 a of the electrode plate 15. A part of the inside of the first resin portion 21A is located between the edge portions 15c of the electrode plates 15 of the bipolar electrodes 14 and 14 adjacent to each other in the stacking direction, and a part of the outside is the edge of the electrode plate 15 It overhangs more than the outside. The first resin portion 21A is buried in the secondary sealing body 22 in a part of the outer side. A stepped portion is provided inside the first resin portion 21A, and an edge portion of the separator 13 is disposed in the stepped portion.

  The second resin portion 21 </ b> B is continuously provided over all the sides of the electrode plate 15 at the edge portion 15 c on the side of the one surface 15 a of the electrode plate 15. In the present embodiment, the second resin portion 21B is provided across the one surface 15a and the end surface 15d of the electrode plate 15, and is coupled to the one surface 15a and the end surface 15d. A part of the inner side of the second resin portion 21 B overlaps the edge 15 c of the electrode plate 15, and a part of the outer side protrudes outward beyond the edge of the electrode plate 15. The second resin portion 21B is buried in the secondary sealing body 22 in a part of the outer side.

  The second resin portion 21 </ b> C is provided continuously over all the sides of the electrode plate 15 at the edge 15 c on the side of the one surface 15 a of the electrode plate 15. In the present embodiment, the second resin portion 21C is provided across the one surface 15a and the end surface 15d of the electrode plate 15, and is coupled to the one surface 15a and the end surface 15d. A part of the inner side of the second resin portion 21 C overlaps the edge 15 c of the electrode plate 15, and a part of the outer side protrudes outward beyond the edge of the electrode plate 15. The second resin portion 21C is buried in the secondary sealing body 22 in a part of the outer side. A step portion is provided inside the second resin portion 21C, and the edge portion of the separator 13 is disposed in the step portion.

  When bonding the primary sealing body 21 (the first resin portion 21A and the second resin portions 21B and 21C) and the electrode plate 15, the bonding surface of the electrode plate 15 with the primary sealing body 21 has a plurality of fine projections It is the roughened plating surface 23 provided. In the present embodiment, the entire surface of one surface 15 a of the electrode plate 15 provided with the positive electrode 16 is a roughened plating surface 23. The fine projection is, for example, a projection-like deposited metal (including an applied substance) formed by electrolytic plating on the electrode plate 15. On the roughened plating surface 23, the resin material constituting the primary sealing body 21 enters into the gaps between the fine projections to produce an anchor effect, and the bonding strength between the electrode plate 15 and the primary sealing body 21 and the liquid Denseness can be improved.

［作用効果］ The first resin portion 21A is made of a first resin material. The second resin portion 21B and the second resin portion 21C are made of a second resin material. In the first resin material and the second resin material, the tensile strength of the second resin material is larger than the tensile strength of the first resin material, and the Young's modulus of the second resin material is larger than the Young's modulus of the first resin material So, it is selected. In the present embodiment, the first resin material is non-oriented polypropylene (CPP: Cast Polypropylene), and the second resin material is biaxially oriented polypropylene (OPP: Oriented Polypropylene). In Table 1 below, examples of properties of non-oriented polypropylene and biaxially oriented polypropylene are shown. In Table 1, the tensile strength of biaxially oriented polypropylene is greater than that of non-oriented polypropylene, and the Young's modulus of biaxially oriented polypropylene is greater than the Young's modulus of non-oriented polypropylene. The tensile strength and the Young's modulus are measured, for example, by the method defined in JIS K 7127.

[Function effect]

  FIG. 3 is an enlarged sectional view of an essential part showing a state of the terminal electrode on the negative electrode side when the internal pressure rises in the storage module according to the comparative example. FIG. 4 is an enlarged sectional view of an essential part showing a state of the positive electrode-side termination electrode when the internal pressure is raised in the storage module according to the comparative example. In the storage module 100 according to the comparative example, unlike the storage module 4 according to the embodiment, the primary sealing body 121 coupled to the negative electrode terminal electrode 118 and the positive electrode terminal electrode 119 has relatively low tensile strength and Young's modulus. It is made of material. In the storage module 100, when the internal pressure of the internal space V between the bipolar electrodes 114, 114 rises due to use conditions etc., the load due to the internal pressure of the internal space V adjacent in the stacking direction is canceled in the intermediate layer of the electrode stack 111. Ru. Further, since the internal space V itself is a slight space, deformation of the bipolar electrode 114 is relatively difficult to occur.

  On the other hand, in the negative electrode termination electrode 118 and the positive electrode termination electrode 119 located at the lamination end of the electrode stack 111, unlike the intermediate layer, the load due to the internal pressure of the internal space V is not canceled. For this reason, as shown in FIGS. 3 and 4, it can be considered that the negative electrode terminal electrode 118 and the positive electrode terminal electrode 119 are deformed outward in the stacking direction when the internal pressure rises. When deformation occurs in the negative electrode termination electrode 118 and the positive electrode termination electrode 119, an excessive stress is applied to the primary sealing body 121, and the primary sealing body 121 is broken or the primary sealing body 121, the negative electrode termination electrode 118, and the positive electrode termination A gap may be generated between the electrode 119 and the electrode 119. The breakage of the primary sealing body 121 and the formation of a gap between the primary sealing body 121 and the negative electrode termination electrode 118 and the positive electrode termination electrode 119 may cause leakage of the electrolyte solution E to the outside of the electrode stack 111.

  On the other hand, in the storage module 4, the tensile strength of the second resin material constituting the second resin portion 21 B bonded to the edge 15 c of the negative electrode terminal electrode 18 is the edge of the electrode plate 15 in the bipolar electrode 14. The tensile strength of the first resin material constituting the first resin portion 21A bonded to the portion 15c is larger than that of the first resin material. Similarly, the tensile strength of the second resin material constituting the second resin portion 21C bonded to the edge 15c of the electrode plate 15 in the positive electrode terminal electrode 19 is connected to the edge 15c of the electrode plate 15 in the bipolar electrode 14 The tensile strength of the first resin material constituting the first resin portion 21A is larger. Thereby, when the internal pressure rises, stress acting on the negative electrode termination electrode 18 and the positive electrode termination electrode 19 can be suitably received by the second resin portions 21B and 21C, and the negative electrode termination electrode 18 and the positive electrode termination when the internal pressure rises. The deformation of the electrode 19 can be suppressed. By suppressing deformation of the negative electrode termination electrode 18 and the positive electrode termination electrode 19, breakage of the second resin portions 21B and 21C, formation of a gap between the second resin portion 21B and the negative electrode termination electrode 18, a second resin portion 21C It is possible to suppress the formation of a gap between the first and second positive electrode terminal electrodes 19 and prevent the electrolyte solution E from leaking out of the electrode stack 11.

  Further, in the storage module 4, the Young's modulus of the second resin material is larger than the Young's modulus of the first resin material. Thereby, deformation of the negative electrode terminal electrode 18 and the positive electrode terminal electrode 19 can be effectively suppressed when the internal pressure rises. Furthermore, since the Young's modulus of the first resin material is relatively small, it is possible to suppress the occurrence of warpage in the first resin portion 21A when welding the first resin portion 21A to the electrode plate 15 of the bipolar electrode 14. As a result, it is possible to preferably laminate the bipolar electrode 14 in the intermediate layer of the electrode laminate 111 while suppressing deformation of the negative electrode termination electrode 18 and the positive electrode termination electrode 19 at the lamination end of the electrode laminate 11.

  Further, in the storage module 4, the second resin material is biaxially oriented polypropylene. Thereby, deformation of the negative electrode terminal electrode 18 and the positive electrode terminal electrode 19 can be effectively suppressed when the internal pressure rises. Furthermore, since the second resin material is polypropylene, the melting point and heat shrinkage ratio of the second resin portions 21B and 21C can be reduced, and the second resin portions 21B and 21C can have alkali resistance. When the melting point and thermal contraction rate of the second resin portion 21B bonded to the negative electrode terminal electrode 18 are small, the bonding strength and liquid tightness between the second resin portion 21B and the electrode plate 15 can be improved, and the negative electrode terminal electrode 18 is The occurrence of the alkaline creep phenomenon can be suppressed. The alkaline creep phenomenon is a phenomenon in which the electrolytic solution E is transmitted on the electrode plate 15 of the negative electrode terminal electrode 18 and exudes to the outer surface side of the electrode plate 15 by passing between the second resin portion 21B and the electrode plate 15.

  Moreover, in the storage module 4, the first resin material is non-oriented polypropylene. As a result, the above-described operation and effect that deformation of the negative electrode terminal electrode 18 and the positive electrode terminal electrode 19 can be suppressed when the internal pressure rises can be suitably exhibited. Furthermore, since the first resin material is polypropylene, the melting point and thermal contraction rate of the first resin portion 21A can be reduced, and the first resin portion 21A can have alkali resistance. When the melting point and the thermal contraction rate of the first resin portion 21A are small, the bonding strength and liquid tightness between the first resin portion 21A and the electrode plate 15 can be improved.

  Further, in the storage module 4, the bonding surface of the electrode plate 15 to the second resin portions 21 B and 21 C is a roughened plating surface 23. Thus, the bonding strength between the electrode plate 15 and the second resin portions 21B and 21C can be improved by the roughening plating surface 23. Therefore, the formation of the gap between the second resin portion 21B and the negative electrode terminal electrode 18 and the formation of the gap between the second resin portion 21C and the positive electrode terminal electrode 19 can be further suitably suppressed.

  The present invention is not limited to the above embodiment. The tensile strength of the second resin material may be greater than the tensile strength of the first resin material, and the combination of the first resin material and the second resin material is not limited to those described above. For example, the second resin material may be uniaxially stretched polypropylene or non-stretched polypropylene, or may be modified polyphenylene ether or the like. The first resin material may be acid-modified polypropylene, modified polyphenylene ether, polypropylene, or a thermoplastic elastomer obtained by mixing a rubber component and polypropylene. Even in these cases, as long as the tensile strength of the second resin material is greater than the tensile strength of the first resin material, the deformation of the negative electrode termination electrode 18 and the positive electrode termination electrode 19 when the internal pressure rises is suppressed as in the above embodiment. it can.

  Only one of the second resin portions 21B and 21C may be made of the second resin material, and the other may be made of a resin material other than the second resin material. For example, the second resin portion 21B bonded to the negative electrode terminal electrode 18 may be made of a second resin material, and the second resin portion 21C bonded to the positive electrode terminal electrode 19 may be made of a first resin material. In this case, the deformation of the negative electrode terminal electrode 18 can be suppressed when the internal pressure rises.

DESCRIPTION OF SYMBOLS 4 ... Storage module, 11 ... Electrode laminated body, 11a ... Side surface, 12 ... Sealed body, 13 ... Separator, 14 ... Bipolar electrode, 15 ... Electrode plate, 15a ... One surface, 15b ... Other surface, 15c ... Edge part, DESCRIPTION OF SYMBOLS 16 ... Positive electrode, 17 ... Negative electrode, 18 ... Negative electrode termination electrode, 19 ... Positive electrode termination electrode, 21A ... 1st resin part, 21B, 21C ... 2nd resin part, 23 ... Roughening plating surface.

Claims (7)

An electrode stack in which a plurality of bipolar electrodes are stacked via a separator;
A sealing body provided on the side surface of the electrode stack and sealing between the bipolar electrodes adjacent in the stacking direction;
The bipolar electrode has an electrode plate having a positive electrode formed on one side and a negative electrode on the other side,
A terminal electrode having an electrode plate in which one of the positive electrode and the negative electrode is formed on the surface facing inward in the stacking direction is disposed at the stacking end of the electrode stack,
The sealing body has a first resin portion coupled to an edge portion of the electrode plate in the bipolar electrode, and a second resin portion coupled to an edge portion of the electrode plate in the terminal electrode,
The electrical storage module, wherein the tensile strength of the second resin material constituting the second resin portion is larger than the tensile strength of the first resin material constituting the first resin portion.   The power storage module according to claim 1, wherein a Young's modulus of the second resin material is larger than a Young's modulus of the first resin material.   The storage module according to claim 1, wherein the second resin material is polypropylene.   The power storage module according to claim 3, wherein the second resin material is a stretched polypropylene.   The storage module according to claim 4, wherein the second resin material is biaxially oriented polypropylene.   The storage module according to any one of claims 1 to 5, wherein the first resin material is non-oriented polypropylene.   The storage module according to any one of claims 1 to 6, wherein a bonding surface of the terminal electrode to the second resin portion in the electrode plate is a roughened plating surface.

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