JP6962170B2 - Power storage module and manufacturing method of power storage module - Google Patents

Description

The present invention relates to a power storage module and a method for manufacturing the power storage module.

As a conventional power storage module, for example, there is a power storage module described in Patent Document 1. This power storage module is a so-called bipolar type power storage module provided with a bipolar electrode having a positive electrode formed on one surface of an electrode plate and a negative electrode formed on the other surface. Such a power storage module includes an electrode laminate formed by laminating a plurality of bipolar electrodes via a separator. On the side surface of the electrode laminate, a sealant is provided to seal between the bipolar electrodes adjacent to each other in the lamination direction.

Japanese Unexamined Patent Publication No. 2011-204386

In forming the above-mentioned encapsulant, for example, the primary encapsulant is arranged at the edge of the electrode plate constituting the bipolar electrode, and the bipolar electrodes having the primary encapsulant are laminated to form the electrode laminate. After that, the primary encapsulants of the bipolar electrodes are bonded to each other by the secondary encapsulant to form the encapsulant. The secondary sealant is formed, for example, by injection molding. At the time of injection molding, for example, the molten resin is injected into the electrode laminate arranged in the mold. At this time, if the withstand voltage of the electrode laminate with respect to the injection pressure of the molten resin is insufficient, the electrode laminate may be deformed.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a power storage module and a method for manufacturing a power storage module capable of suppressing deformation of an electrode laminate during formation of a sealed body.

The power storage module according to one aspect of the present invention includes an electrode laminate in which a plurality of bipolar electrodes are laminated, and a sealer that seals between bipolar electrodes adjacent to each other in the stacking direction in the electrode laminate, and seals the electrode laminate. The body has a group of primary encapsulants provided at the edges of electrode plates constituting a plurality of bipolar electrodes, and a secondary encapsulant that joins a group of primary encapsulants, and is a primary encapsulation body. The group of stop bodies is composed of a plurality of resin materials having different static friction coefficients, and in the group of primary encapsulants, the outer surface of the primary encapsulant located at the stacking end in the stacking direction is a plurality of resin materials. It is composed of a resin material with the highest static friction coefficient.

In this power storage module, the outer surface of the primary sealant located at the stacking end in the stacking direction in the stacking direction is composed of the resin material having the highest coefficient of static friction among the plurality of resin materials constituting the group of the primary sealant. Has been done. When the secondary sealant is formed by injection molding, the pressure resistance of the electrode laminate with respect to the injection pressure of the molten resin is the compressive reaction force due to the compressive force applied in the stacking direction of the electrode laminate by the mold and the gold. It is determined by the product of the coefficient of static friction of the outer surface of the primary sealant in contact with the mold in the stacking direction. Therefore, by sufficiently securing the coefficient of static friction of the outer surface of the primary encapsulant in the laminating direction, it is possible to increase the withstand voltage of the electrode laminate with respect to the injection pressure of the molten resin, and the electrode laminate at the time of forming the encapsulant. Deformation can be suppressed.

Further, in a plurality of resin materials, when the resin material having the highest coefficient of friction is used as the first resin material and the resin material other than the first resin material is used as the second resin material, in the group of primary encapsulants. The primary encapsulant located at the lamination end in the lamination direction is formed in a single layer by the first resin material, and the primary encapsulant located in the middle of the lamination direction is formed into a single layer by the second resin material. It may be formed. In this case, it is possible to avoid complication of the configuration of the electrode laminate while increasing the withstand voltage of the electrode laminate.

Further, in a plurality of resin materials, when the resin material having the highest coefficient of friction is used as the first resin material and the resin material other than the first resin material is used as the second resin material, in the group of primary encapsulants. The primary encapsulant located at the lamination end in the lamination direction is formed in a single layer by the first resin material, and the primary encapsulant located in the middle of the lamination direction is the first resin in order from the electrode plate side. It may be formed into a plurality of layers by the material and the second resin material. In this case, it is possible to avoid complication of the configuration of the electrode laminate while increasing the withstand voltage of the electrode laminate.

Further, in the method for manufacturing a power storage module according to one aspect of the present invention, electrodes including a bipolar electrode with a primary sealant formed by arranging a primary sealant on the edge of an electrode plate constituting the bipolar electrode are laminated. In the process of forming the electrode laminate to form the electrode laminate, the electrode laminate is placed in a mold for injection molding so that a compressive force in the stacking direction is applied to the electrode laminate, and the molten resin is placed in the mold. A plurality of resin materials constituting a group of primary sealants in an electrode laminate forming step, comprising a sealant forming step of forming a secondary sealant by injecting and binding a group of primary sealants. By forming the outer surface of the primary sealant located at the stacking end in the stacking direction in the stacking direction with the resin material having the highest static friction coefficient, and pressing the outer surface with a mold in the sealing body forming step. Applying compressive force to the electrode laminate.

In this method of manufacturing a power storage module, the outer surface of the primary encapsulant located at the lamination end in the laminating direction is the resin having the highest coefficient of static friction among the plurality of resin materials constituting the group of the primary encapsulants. Consists of materials. When the secondary sealant is formed by injection molding, the pressure resistance of the electrode laminate with respect to the injection pressure of the molten resin is the compressive reaction force due to the compressive force applied in the stacking direction of the electrode laminate by the mold and the gold. It is determined by the product of the coefficient of static friction of the outer surface of the primary sealant in contact with the mold in the stacking direction. Therefore, by sufficiently securing the coefficient of static friction of the outer surface of the primary encapsulant in the laminating direction, it is possible to increase the withstand voltage of the electrode laminate with respect to the injection pressure of the molten resin, and the electrode laminate at the time of forming the encapsulant. Deformation can be suppressed.

According to the present invention, deformation of the electrode laminate during formation of the sealing body can be suppressed.

It is the schematic which shows one Embodiment of the power storage device. It is schematic cross-sectional view which shows one Embodiment of the power storage module which constitutes the power storage device. It is an enlarged schematic view of the main part which shows an example of the structure of the sealing body. It is a flowchart which shows one Embodiment of the manufacturing method of the power storage module. It is the schematic which shows an example of the electrode laminate formation process. It is the schematic which shows an example of the sealing body forming process. It is an enlarged schematic view of the main part which shows the modification of the power storage module. It is an enlarged schematic view of a main part which shows another modification of a power storage module.

Hereinafter, preferred embodiments of the power storage module and the method for manufacturing the power storage module according to one aspect of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic cross-sectional view showing an embodiment of a power storage device. The power storage device 1 shown in the figure is a device used as a battery for various vehicles such as forklifts, hybrid vehicles, and electric vehicles. The power storage device 1 includes a power storage module stack 2 obtained by stacking a plurality of power storage modules 4, and a restraint member 3 that applies a restraint load to the power storage module stack 2 in the stacking direction.

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

In the power storage module stack 2, the power storage modules 4 and 4 adjacent to each other in the stacking direction are electrically connected to each other via the conductive plate 5. The conductive plates 5 are arranged between the storage modules 4 and 4 adjacent to each other in the stacking direction and outside the power storage modules 4 located at the stacking ends. A positive electrode terminal 6 is connected to one of the conductive plates 5 arranged outside the power storage module 4 located at the laminated end. The negative electrode terminal 7 is connected to the other conductive plate 5 arranged outside the power storage module 4 located at the laminated end. The positive electrode terminal 6 and the negative electrode terminal 7 are drawn out from the edge of the conductive plate 5, for example, in a direction intersecting with each other in the stacking direction. The positive electrode terminal 6 and the negative electrode terminal 7 charge and discharge the power storage device 1.

Inside each conductive plate 5, a plurality of flow paths 5a through which a refrigerant such as air flows are provided. Each flow path 5a extends parallel to each other, for example, in a direction orthogonal to the stacking direction and the drawing direction of the positive electrode terminal 6 and the negative electrode terminal 7. By circulating the refrigerant through these flow paths 5a, the conductive plate 5 not only functions as a connecting member for electrically connecting the storage modules 4 and 4 to each other, but also a heat radiating plate that dissipates heat generated by the power storage module 4. It also has the function of. In the example of FIG. 1, the area of the conductive plate 5 seen from the stacking direction is smaller than the area of the power storage module 4, but from the viewpoint of improving heat dissipation, the area of the conductive plate 5 is the power storage module. It may be the same as the area of 4, and may be larger than the area of the power storage module 4.

The restraint member 3 is composed of a pair of end plates 8 and 8 that sandwich the power storage module laminate 2 in the stacking direction, and a fastening bolt 9 and a nut 10 that fasten the end plates 8 and 8 to each other. The end plate 8 is a rectangular metal plate having an area one size larger than the area of the power storage module 4 and the conductive plate 5 when viewed from the stacking direction. A film F having electrical insulation is provided on the inner surface of the end plate 8 (the surface on the side of the storage module laminate 2). The film F electrically insulates between the end plate 8 and the conductive plate 5.

An insertion hole 8a is provided at the edge of the end plate 8 at a position outside the power storage module laminate 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 is attached to the tip portion of the fastening bolt 9 protruding from the insertion hole 8a of the other end plate 8. , The nut 10 is screwed. As a result, the power storage module 4 and the conductive plate 5 are sandwiched by the end plates 8 and 8 to be unitized as the power storage module stack 2, and a restraining load is applied to the power storage module stack 2 in the stacking direction.

Next, the configuration of the power storage module 4 will be described. FIG. 2 is a schematic cross-sectional view showing an embodiment of the power storage module. As shown in the figure, the power storage module 4 includes an electrode laminate 11 and a resin sealant 12 that seals the electrode laminate 11.

The electrode laminate 11 is configured by laminating a plurality of bipolar electrodes 14 via a separator 13. In the present embodiment, the stacking direction of the electrode laminated body 11 and the stacking direction of the power storage module laminated body 2 are the same. The electrode laminate 11 has a side surface 11a extending in the lamination direction. The bipolar electrode 14 includes an electrode plate 15, a positive electrode 16 provided on one surface 15a of the electrode plate 15, and a negative electrode 17 provided on the other surface 15b of the electrode plate 15.

The positive electrode 16 is a positive electrode active material layer coated with a positive electrode active material. The negative electrode 17 is a negative electrode active material layer coated with a negative electrode active material. In the electrode laminate 11, the positive electrode 16 of one bipolar electrode 14 faces the negative electrode 17 of one of the bipolar electrodes 14 adjacent to each other in the stacking direction with the separator 13 interposed therebetween. In the electrode laminate 11, the negative electrode 17 of one bipolar electrode 14 faces the positive electrode 16 of the other bipolar electrode 14 adjacent to each other in the stacking direction with the separator 13 interposed therebetween.

In the electrode laminate 11, the negative electrode terminal electrode 18 is arranged at one end in the lamination direction. Further, a positive electrode terminal electrode 19 is arranged at the other end in the stacking direction. The negative electrode terminal electrode 18 includes an electrode plate 15 and a negative electrode 17 provided on the other surface 15b 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 power storage module 4 is in contact with one surface 15a of the electrode plate 15 of the negative electrode terminal electrode 18. The positive electrode terminal electrode 19 includes an electrode plate 15 and a positive electrode 16 provided on one surface 15a of the electrode plate 15. The other conductive plate 5 adjacent to the power storage module 4 is in contact with the other surface 15b of the electrode plate 15 of the positive electrode terminal electrode 19. The positive electrode 16 of the positive electrode terminal electrode 19 faces 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 portion 15c of the electrode plate 15 is an uncoated region in which the positive electrode active material and the negative electrode active material are not coated. Examples of the positive electrode active material constituting the positive electrode 16 include nickel hydroxide. Examples of the negative electrode active material constituting the negative electrode 17 include a hydrogen storage alloy. In the present embodiment, the formation region of the negative electrode 17 on the other surface 15b of the electrode plate 15 is slightly larger than the formation region of the positive electrode 16 on the one surface 15a of the electrode plate 15.

The separator 13 is formed in a sheet shape, for example. Examples of the separator 13 include a porous film made of a polyolefin resin such as polyethylene (PE) and polypropylene (PP), a woven cloth made of polypropylene or the like, or a non-woven fabric. The separator 13 may be reinforced with a vinylidene fluoride resin compound. The separator 13 is not limited to a sheet shape, and a bag shape may be used.

The sealing body 12 is formed in a rectangular tubular shape by, for example, an insulating resin. The sealing body 12 is configured to hold the edge portion 15c of the electrode plate 15 on the side surface 11a of the electrode laminated body 11 extending in the stacking direction and to surround the side surface 11a. The sealing body 12 is provided so as to surround the primary sealing body 21 provided along the edge portion 15c of the electrode plate 15 of each bipolar electrode 14 and the group H of the primary sealing body 21 from the outside. It is composed of a secondary sealing body 22 and the like.

The primary encapsulant 21 is formed by, for example, injection molding of resin, and is continuously provided over all sides of the electrode plate 15 at the edge portion 15c (uncoated region) on the one side 15a side of the electrode plate 15. There is. The primary sealant 21 has a function as a spacer between the electrode plates 15 and 15 of the bipolar electrodes 14 and 14 adjacent to each other in the stacking direction. An internal space V defined by the spacing between the primary encapsulants 21 and 21 in the stacking direction is formed between the electrode plates 15 and 15. The internal space V contains an electrolytic solution E composed of an alkaline solution such as an aqueous potassium hydroxide solution.

The primary sealing body 21 has an overlapping portion 21a that overlaps the edge portion 15c of the electrode plate 15, and an overhanging portion 21b that projects outward from the edge of the electrode plate 15. At least a part of the overlapping portion 21a is firmly bonded to the edge portion 15c by welding using, for example, ultrasonic waves or heat. In connecting the primary sealing body 21 and the electrode plate 15, the bonding surface of the electrode plate 15 with the primary sealing body 21 is a roughened plated surface provided with a plurality of fine protrusions.

In the present embodiment, the entire surface of one surface 15a of the electrode plate 15 on which the positive electrode 16 is provided is a roughened plated surface. The fine protrusions are, for example, a protrusion-shaped precipitated metal (including an impart) formed by electrolytic plating on the electrode plate 15. On the roughened plated surface, the resin material constituting the primary encapsulant 21 enters the gaps between the fine protrusions to produce an anchor effect, and the bond strength and liquid tightness between the electrode plate 15 and the primary encapsulant 21 are formed. The sex is improved.

FIG. 3 is an enlarged schematic view of a main part showing an example of the configuration of the sealed body. In the example of the figure, for the sake of simplification of the description, the separator 13 is omitted, and the stepped portion where the separator 13 overlaps is omitted in the primary sealing body 21. As shown in FIG. 3, the electrode laminated body 11 is formed with a group H of the primary encapsulant 21 by laminating the bipolar electrode 14, the negative electrode terminal electrode 18, and the positive electrode terminal electrode 19. Group H of the primary sealant 21 is composed of a plurality of resin materials having different coefficients of static friction. Further, in the group H of the primary sealing bodies 21, the outer surface Ha of the primary sealing body 21 located at the stacking end in the stacking direction of the electrode laminated body 11 has the highest coefficient of static friction among the plurality of resin materials. It is composed of high resin material.

In the present embodiment, when the resin material having the highest coefficient of friction among the plurality of resin materials is the first resin material 21A and the resin material other than the first resin material 21A is the second resin material 21B, it is primary. In the group H of the sealing bodies 21, the primary sealing body 21 located at the stacking end of the electrode laminated body 11 in the stacking direction is formed in a single layer by the first resin material 21A. Further, in the group H of the primary sealing bodies 21, the primary sealing body 21 located in the middle of the stacking direction of the electrode laminated bodies 11 is formed in a single layer by the second resin material 21B.

In the example of FIG. 3, the primary sealant 21 formed on the edge portion 15c of the one surface 15a of the electrode plate 15 in the negative electrode terminal electrode 18 and the edge portion 15c of the other surface 15b of the electrode plate 15 in the positive electrode terminal electrode 19 The formed primary sealant 21 is formed of the first resin material 21A. On the other hand, the primary encapsulant 21 formed on the edge 15c of the one side 15a of the electrode plate 15 in the bipolar electrode 14 forming the intermediate layer of the electrode laminate 11 and the one side 15a of the electrode plate 15 in the positive electrode terminal electrode 19 The primary sealing body 21 formed on the edge portion 15c of the above is formed of the first resin material 21A.

Examples of the first resin material 21A include an elastomer in which a rubber component and polypropylene are mixed, an acid-modified polypropylene, and the like. Examples of the second resin material 21B include modified polyphenylene ethers such as Zylon (registered trademark) and polypropylene.

The secondary encapsulant 22 is formed by, for example, injection molding of a resin, and extends over the entire length of the electrode laminate 11 in the lamination direction. The secondary encapsulant 22 is welded to the outer surface of each primary encapsulant 21 by heat during injection molding, for example, and bonds the group H of the primary encapsulant 21. Further, the secondary encapsulant 22 also enters between the primary encapsulants 21 and 21 adjacent to each other in the stacking direction, and is firmly bonded to the group H of the primary encapsulant 21. With such a configuration, the electrolytic solution E housed in the internal space V can pass between the primary encapsulants 21 and 21 adjacent to each other in the stacking direction, but the primary encapsulant 21 and the secondary encapsulant 22 It is sealed at the welded part.

Subsequently, a method of manufacturing the power storage module 4 will be described. FIG. 4 is a flowchart showing an embodiment of the above-described storage module manufacturing method. As shown in the figure, the method for manufacturing the power storage module includes an electrode laminate forming step (step S01) and a sealing body forming step (step S02).

In the electrode laminate forming step, for example, as shown in FIG. 5, a bipolar electrode 32 with a primary encapsulant formed by preliminarily welding the primary encapsulant 21 to the edge portion 15c of the electrode plate 15 constituting the bipolar electrode 14 is specified. Stack several. Further, a negative electrode terminal 33 with a primary sealant in which the primary sealant 21 is arranged in advance on the edge portion 15c of the electrode plate 15 constituting the negative electrode terminal electrode 18, and an electrode plate 15 constituting the positive electrode terminal plate 19 The positive electrode termination electrode 34 with a primary sealant in which the primary sealant 21 is arranged in advance on the edge portion 15c is arranged so as to sandwich the laminate of the bipolar electrode 32 with the primary sealant in the stacking direction, and the electrodes are laminated. Get body 11.

In the bipolar electrode 32 with the primary sealant, the primary sealant 21 is formed in a single layer by the second resin material 21B, and in the negative electrode terminal 33 with the primary sealant, the primary sealant 21 is the first. It is formed in a single layer by the resin material 21A of. Further, in the positive electrode terminal 34 with the primary sealing body, the primary sealing body 21 on the one side 15a side is formed in a single layer by the second resin material 21B, and the primary sealing body 21 on the other side 15b side is the first. It is formed in a single layer by the resin material 21A of. Therefore, in the group H of the primary sealing bodies 21, the outer surface Ha of the primary sealing body 21 located at the stacking end in the stacking direction of the electrode laminated body 11 has the highest coefficient of static friction among the plurality of resin materials. It will be composed of high resin material.

In the sealing body forming step, as shown in FIG. 6, the electrode laminate 11 is arranged in the injection molding die K. At this time, the mold K presses the outer surface Ha of the primary sealing body 21 located at the stacking end in the stacking direction of the electrode laminated body 11 in the stacking direction to apply a compressive force in the stacking direction to the electrode laminated body 11. Then, the molten resin is injected into the mold K from the injection port (not shown) provided in the mold K to form the secondary sealing body 22 on the outer surface of the group H of the primary sealing body 21. As a result, the group H of the primary sealing body 21 is bonded by the secondary sealing body 22, and the sealing body 12 is formed.

In this sealing body forming step, the pressure resistance of the electrode laminate 11 with respect to the injection pressure P of the molten resin injected into the mold K is due to the compressive force applied by the mold K in the stacking direction of the electrode laminate 11. It is proportional to the product of the compressive reaction force F to be generated and the coefficient of static friction μ of the outer surface Ha of the primary sealing body 21 in contact with the mold K in the stacking direction. Therefore, for the same compression reaction force F, the higher the coefficient of static friction μ of the outer surface Ha, the higher the withstand voltage of the electrode laminate 11.

The compression reaction force F can be obtained based on the product of the compression surface pressure and the compression width B. The compressed surface pressure is the compressibility of the group H of the primary encapsulant 21 (≈ thickness t _{1 after compression of the electrode laminate 11 / thickness t 0} before compression of the electrode laminate 11) and the primary encapsulant 21. It can be obtained based on the product of the group H with the young rate. The compression width B can be obtained based on the width of the overlapping portion 21a that overlaps the edge portion 15c of the electrode plate 15.

As described above, in the power storage module 4 and the manufacturing method thereof, a plurality of outer surfaces Ha in the stacking direction of the primary sealing bodies 21 located at the stacking ends in the stacking direction form a group H of the primary sealing bodies 21. It is composed of a resin material having the highest coefficient of static friction among the resin materials. As described above, when the secondary sealing body 22 is formed by injection molding, the pressure resistance of the electrode laminated body 11 with respect to the injection pressure of the molten resin is a compressive force applied by the mold K in the laminating direction of the electrode laminated body 11. It is determined by the product of the compressive reaction force caused by the above and the coefficient of static friction of the outer surface Ha of the primary sealing body 21 in contact with the mold K in the stacking direction. Therefore, by sufficiently securing the coefficient of static friction of the outer surface Ha of the primary sealing body 21 in the stacking direction, it is possible to increase the withstand voltage of the electrode laminated body 11 with respect to the injection pressure of the molten resin, and at the time of forming the sealing body. Deformation of the electrode laminate 11 can be suppressed.

Further, in the present embodiment, in the group H of the primary sealing bodies 21, the primary sealing body 21 located at the stacking end in the stacking direction is formed in a single layer by the first resin material 21A, and is formed in a single layer in the stacking direction. The primary encapsulant 21 located in the middle is formed in a single layer by the second resin material 21B. With such a configuration, it is possible to avoid complication of the configuration of the electrode laminate 11 while increasing the withstand voltage of the electrode laminate 11.

The present invention is not limited to the above embodiment. For example, in the group H of the primary encapsulants 21, for example, as shown in FIG. 7, the primary encapsulants 21 located at the lamination ends of the electrode laminates 11 in the lamination direction are formed into a single layer by the first resin material 21A. The primary encapsulant 21 located in the middle of the electrode laminate 11 in the lamination direction may be formed in a plurality of layers by the first resin material 21A and the second resin material 21B. In the example of FIG. 7, the primary sealing body 21 located at the stacking end of the electrode laminated body 11 in the stacking direction is formed of a single layer by the first resin material 21A as in the case of FIG. Further, the primary encapsulant 21 located in the middle of the electrode laminate 11 in the lamination direction is composed of two layers of the first resin material 21A and the second resin material 21B formed in order from the electrode plate 15 side. ing.

Even in such a configuration, the coefficient of static friction of the outer surface Ha of the primary sealing body 21 in the stacking direction can be sufficiently secured, and the withstand voltage of the electrode laminated body 11 can be increased. Further, it is possible to avoid complication of the configuration of the electrode laminate 11. In order to simplify the manufacturing process, it is preferable that the first resin material 21A and the second resin material 21B constituting the primary sealing body 21 of the intermediate layer have the same thickness.

Further, in the group H of the primary sealing bodies 21, for example, as shown in FIG. 8, the primary sealing bodies 21 located at the stacking ends of the electrode laminated bodies 11 in the stacking direction are formed into a plurality of layers by the first resin material 21A. The primary encapsulant 21 located in the middle of the electrode laminate 11 in the stacking direction may be formed in a plurality of layers by the first resin material 21A and the second resin material 21B. In the example of FIG. 8, the primary sealing body 21 located at the stacking end of the electrode laminated body 11 in the stacking direction is composed of two layers of the first resin materials 21A and 21A. Further, the primary encapsulant 21 located in the middle of the electrode laminate 11 in the lamination direction is the first resin material 21A and the second resin material formed in order from the electrode plate 15 side, as in the case of FIG. It is composed of two layers by 21B.

Even in such a configuration, the coefficient of static friction of the outer surface Ha of the primary sealing body 21 in the stacking direction can be sufficiently secured, and the withstand voltage of the electrode laminated body 11 can be increased. Further, it is possible to avoid complication of the configuration of the electrode laminate 11. In order to simplify the manufacturing process, it is preferable that the first resin materials 21A and 21A constituting the primary sealing body 21 at the laminated end have the same thickness. Further, the thicknesses of the first resin material 21A and the second resin material 21B constituting the primary sealing body 21 of the intermediate layer are preferably the same.

4 ... Energy storage module, 11 ... Electrode laminate, 12 ... Sealing body, 14 ... Bipolar electrode, 15 ... Electrode plate, 15c ... Edge, 21 ... Primary sealing body, 21A ... First resin material, 21B ... First 2 resin material, 22 ... secondary encapsulant, H ... group of primary encapsulant, Ha ... outer surface, K ... mold.

Claims (4)

An electrode laminate in which multiple bipolar electrodes are laminated, and
The electrode laminate includes a sealant that seals between the bipolar electrodes adjacent to each other in the stacking direction.
The encapsulant includes a group of primary encapsulants provided at the edges of electrode plates constituting the plurality of bipolar electrodes, and a secondary encapsulant that combines the group of primary encapsulants. Have and
The group of primary sealants is composed of a plurality of resin materials having different coefficients of static friction.
In the group of the primary sealants, the outer surface of the primary sealant located at the stacking end in the stacking direction in the stacking direction is composed of a resin material having the highest coefficient of static friction among the plurality of resin materials. Power storage module. When the resin material having the highest friction coefficient among the plurality of resin materials is used as the first resin material and the resin material other than the first resin material is used as the second resin material,
In the group of primary sealants, the primary sealant located at the stacking end in the stacking direction is formed in a single layer by the first resin material, and the primary sealant is located in the middle of the stacking direction. The power storage module according to claim 1, wherein the encapsulant is formed in a single layer by the second resin material. When the resin material having the highest friction coefficient among the plurality of resin materials is used as the first resin material and the resin material other than the first resin material is used as the second resin material,
In the group of primary sealants, the primary sealant located at the stacking end in the stacking direction is formed in a single layer by the first resin material, and the primary sealant is located in the middle of the stacking direction. The power storage module according to claim 1, wherein the encapsulant is formed in a plurality of layers by the first resin material and the second resin material in order from the electrode plate side. An electrode laminate forming step of laminating electrodes including a bipolar electrode with a primary seal, which is formed by arranging a primary seal on the edge of an electrode plate constituting the bipolar electrode, to form an electrode laminate.
The electrode laminate is arranged in a mold for injection molding so that a compressive force in the stacking direction is applied to the electrode laminate, and a molten resin is injected into the mold to form a group of the primary encapsulants. The encapsulant forming step of forming the secondary encapsulant is provided.
In the electrode laminate forming step, the lamination of the primary encapsulant located at the lamination end in the lamination direction by the resin material having the highest coefficient of static friction among the plurality of resin materials constituting the group of the primary encapsulants. Consists of the outer surface of the direction,
A method for manufacturing a power storage module that applies a compressive force to the electrode laminate by pressing the outer surface with the mold in the sealing body forming step.

Images