JP6927077B2 - Manufacturing method of power storage device - Google Patents

Description

The present invention relates to a method for manufacturing a power storage device.

As a conventional power storage device, a bipolar battery provided with a bipolar electrode is known (see, for example, Patent Document 1). A bipolar electrode is an 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. A sealant is laminated on the edge of the bipolar electrode. With this encapsulant, when a plurality of bipolar electrodes are laminated, each bipolar electrode is sealed.

Japanese Unexamined Patent Publication No. 2005-190713

The sealant is welded to the electrode plate of the bipolar electrode. Therefore, before welding, the sealed body is laminated with the sealed body aligned with the electrode plate. After that, the bipolar electrode on which the encapsulant is laminated is conveyed to the welding machine. However, since the encapsulant is made of a soft material, the shape of the encapsulant may be deformed during transportation. When such deformation occurs, the quality of the power storage device may be affected.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a method for manufacturing a power storage device capable of improving the quality of the power storage device.

The method for manufacturing a power storage device according to one aspect of the present invention is a method for manufacturing a power storage device having a bipolar electrode composed of an electrode plate having a positive electrode formed on one surface and a negative electrode formed on the other surface. A frame-shaped encapsulant is laminated and pressed along the edge portion to weld the encapsulant to the electrode plate, and after the welding step, at least a part of the outer peripheral edge of the encapsulant is formed. It includes a cutting step for cutting.

The manufacturing method of this power storage device includes a welding step of welding the sealing body to the electrode plate by laminating and pressing the sealing body along the edge of the electrode plate. Such a sealing body seals between each bipolar electrode when a plurality of bipolar electrodes are laminated. Here, the method for manufacturing the power storage device includes a cutting step of cutting at least a part of the outer peripheral edge portion of the sealing body after the welding step. In this case, the outer peripheral edge of the sealed body is cut while being welded to the electrode plate by welding. That is, since the edge portion of the sealing body is cut in a state of being positioned with respect to the electrode plate, it is possible to form an outer peripheral edge having a desired shape. Further, the sealed body before cutting is made wider by the cutting allowance than the final sealed body after cutting. That is, the rigidity of the sealed body before cutting can be increased. Therefore, since the deformation of the sealed body before the welding step can be suppressed, the deformation of the inner peripheral edge can also be suppressed. As described above, the quality of the power storage device can be improved.

Further, the method for manufacturing the power storage device further includes an electrode laminate forming step of forming an electrode laminate by laminating a plurality of bipolar electrodes having a sealed body welded to the electrode plate, and the cutting step is an electrode laminate. Prior to the forming step, it may be performed individually for each encapsulation. In this case, the positional relationship between the bipolar electrode and the sealing body at the time of cutting is accurately adjusted for each sheet. Therefore, the outer peripheral edge of the sealed body after each cutting is in a state of being accurately aligned with the bipolar electrode. Therefore, in the electrode laminate forming step, positioning between the stacked bipolar electrodes can be performed accurately.

Further, in the method for manufacturing a power storage device, the sealing body is formed in a rectangular shape, has a pair of long sides and a pair of short sides, and at least the edge corresponding to the long side may be cut in the cutting step. The encapsulant is easily deformed at the position corresponding to the long side. Therefore, in the cutting step, the easily deformable portion is cut, so that the above-mentioned effect can be remarkably obtained.

According to the present invention, it is possible to provide a method for manufacturing a power storage device that can improve the quality of the power storage device.

It is a schematic cross-sectional view which shows one Embodiment of a power storage device. It is a schematic cross-sectional view which shows the internal structure of the power storage module. It is the schematic cross-sectional view which shows the structure of the sealing body. It is a flow chart which shows the flow of the manufacturing method of a power storage device. It is a conceptual diagram for demonstrating the manufacturing method of a power storage device. It is a conceptual diagram for demonstrating the manufacturing method of a power storage device. It is a conceptual diagram for demonstrating the manufacturing method of a power storage device. It is a conceptual diagram for demonstrating the manufacturing method of a power storage device.

Hereinafter, preferred embodiments of the electrode manufacturing method 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 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 conductive plates 5 arranged between the power storage modules 4 and 4. 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.

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 also arranged on the outside of the power storage module 4 located at the laminated end. A positive electrode terminal 6 is connected to one of the conductive plates 5 arranged outside the power storage module. Further, the negative electrode terminal 7 is connected to the other conductive plate 5 arranged outside the power storage module. 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 area of the power storage module 4. It may be the same as, 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 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 in more detail. FIG. 2 is a schematic cross-sectional view showing the internal configuration of the power storage module 4. As shown in the figure, the power storage module 4 includes an electrode laminated body 11 and a sealing body 12 that seals the electrode laminated body 11.

The electrode laminate 11 is configured by laminating a plurality of bipolar electrodes 14 via a separator 13. The bipolar electrode 14 is an electrode composed of an electrode plate 15 having a positive electrode 16 formed on one side 15a and a negative electrode 17 formed on the other side 15b. 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. Further, 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.

Further, the negative electrode terminal electrode 18 is arranged on one of the laminated ends of the electrode laminated body 11, and the positive electrode terminal electrode 19 is arranged on the other side of the laminated end of the electrode laminated body 11. The negative electrode terminal electrode 18 is an electrode plate 15 having a negative electrode 17 formed on the inner surface side (center side in the stacking direction), and the positive electrode terminal electrode 19 has a positive electrode 16 formed on the inner surface side (center side in the stacking direction). The electrode plate 15. The negative electrode 17 of the negative electrode terminal electrode 18 faces the positive electrode 16 of one of the bipolar electrodes 14 at the laminated end via the separator 13. The positive electrode 16 of the positive electrode terminal electrode 19 faces the negative electrode 17 of the other bipolar electrode 14 at the laminated end via the separator 13. The electrode plate 15 of the negative electrode terminal electrode 18 and the electrode plate 15 of the positive electrode terminal 19 are electrically connected to the conductive plate 5 (see FIG. 1) adjacent to the power storage module 4.

The electrode plate 15 is a rectangular metal foil made of, for example, nickel. The edge portion (edge portion of the bipolar electrode 14) 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, and the uncoated region is buried in the sealing body 12. Is held. Examples of the positive electrode active material constituting the positive electrode 16 include nickel hydroxide. Further, 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 material for forming the separator 13 include a porous film made of a polyolefin resin such as polyethylene (PE) and polypropylene (PP), a woven fabric made of polypropylene, polyethylene terephthalate (PET), methyl cellulose and the like, or a non-woven fabric. .. Further, 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. Examples of the resin material constituting the sealing body 12 include polypropylene (PP), polyphenylene sulfide (PPS), modified polyphenylene ether (modified PPE), and the like. The sealing body 12 is configured to surround the side surface 11a of the electrode laminated body 11 formed by laminating the bipolar electrodes 14.

As shown in FIGS. 2 and 3, the sealing body 12 is provided so as to surround the primary sealing body 21 provided along the edge of the electrode plate 15 of the bipolar electrode 14 and the primary sealing body 21. It is composed of the secondary sealing body 22 provided. The primary sealant 21 is formed, for example, by injection molding of a 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 is bonded to the edge portion 15c by, for example, welding.

The primary sealant 21 seals between the bipolar electrodes 14 and 14 adjacent to each other in the stacking direction, and also functions 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 thickness of the primary sealant 21 is formed between the electrode plates 15 and 15, and the internal space V is an electrolytic solution (non-existent) composed of an alkaline solution such as an aqueous potassium hydroxide solution. (Shown) is housed. In the examples of FIGS. 2 and 3, the primary encapsulant 21 is formed only on the one side 15a side of the electrode plate 15, but the primary encapsulant 21 is formed on both the one side 15a and the other surface 15b. It may be formed so that the edge portion 15c of the electrode plate 15 is buried.

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 the primary encapsulant 21 and the end face of the edge portion 15c of the electrode plate 15 by heat during injection molding, for example. As shown in FIG. 3, the secondary sealing body 22 is provided with a thick portion 23 projecting to the outside of the electrode laminated body 11. The wall thickness portion 23 has a thickness about twice that of the other portion of the secondary sealing body 22, and is provided with a constant width corresponding to the central portion of each side of the electrode plate 15. There is.

Subsequently, the manufacturing method of the power storage device 1 described above will be described.

As shown in FIG. 4, the manufacturing method of the power storage device 1 according to the present embodiment includes an electrode manufacturing step S1, an electrode laminate forming step S2, and a sealing body forming step S3. The electrode manufacturing step S1 is a step of manufacturing the bipolar electrode 14 with the primary sealing body 21. The electrode manufacturing step S1 includes a primary sealing body forming step S10, an electrode forming step S11, a laminating step S12, a welding step S13, and a cutting step S14. The manufacturing method will be described with reference to FIGS. 5 to 8 as appropriate. In FIGS. 5 to 8, the size and the degree of overlap of the edges of the respective components are deformed in order to explain the manufacturing method. Shown in state.

The primary sealing body forming step S10 is a step of forming the primary sealing body. The method for forming the primary sealant is not particularly limited. For example, the primary encapsulant may be formed by punching a resin sheet material into a desired shape. In the primary sealing body forming step S10 in the present embodiment, as shown in FIG. 5A, the primary sealing body is formed in a state of being expanded in size from the primary sealing body 21 finally arranged in the power storage device 1. NS. The primary encapsulant in the expanded state in this way is referred to as an extended encapsulant 50 in distinction from the primary encapsulant 21 finally arranged in the power storage device 1. The extended sealing body 50 is a member in which the outer peripheral side edge portion 21c of the primary sealing body 21 is expanded. The expansion sealing body 50 has an expansion portion 50a in which the outer peripheral edges 21a on the long side and the short side are expanded. The size of the expansion portion 50a is not particularly limited, but it must be large enough to be cut with a cutting tool.

The electrode forming step S11 is a step of forming the electrode plate 15. As shown in FIG. 5B, in the electrode plate forming step S11, the electrode plate 15 is formed by cutting the base material 51. The base material 51 is a sheet member of a long metal leaf, and has a positive electrode 16 and a negative electrode 17 at this pitch along the longitudinal direction. The base metal 51 is cut at the cutting line CL1 between a pair of positive electrodes 16 adjacent to each other in the longitudinal direction. The cut ends formed by cutting the base material 51 along the cutting line CL1 are the outer peripheral edge 15d and the outer peripheral edge 15e facing each other in the electrode plate 15. The side edges of the base material 51 are an outer peripheral edge 15f and an outer peripheral edge 15g that face each other in the electrode plate 15. In the present embodiment, the outer peripheral edges 15d and 15e are the short sides of the electrode plate 15, and the outer peripheral edges 15f and 15g are the long sides of the electrode.

The laminating step S12 is a step of laminating the electrode plate 15 of the bipolar electrode 14 and the expansion sealing body 50. In the laminating step S12, as shown in FIG. 6A, the extended sealing body 50 is arranged so as to cover the edge portion 15c of the electrode plate 15 at a portion corresponding to the primary sealing body 21. The portion of the primary sealing body 21 corresponding to the outer peripheral edge 21a is arranged so as to protrude toward the outer peripheral side of the edge portion 15c of the electrode plate 15. The portion of the primary sealing body 21 corresponding to the inner peripheral edge 21b is arranged on the inner peripheral side of the edge portion 15c of the electrode plate 15. The primary sealant 21 is laminated on the one side 15a side of the electrode plate 15 (see FIG. 7).

The welding step S13 is a step of welding the expansion sealing body 50 to the electrode plate 15 by laminating and pressing the expansion sealing body 50 along the edge portion 15c of the electrode plate 15. In the present embodiment, the portion corresponding to the primary sealing body 21 of the extended sealing body 50 is welded to the edge portion 15c of the electrode plate 15. In the welding step S13, as shown in FIG. 6B, the welding portion 53 is formed with respect to the four sides of the edge portion 15c of the electrode plate 15. The welded portion 53 is formed in a portion of the four sides where the edge portion 15c of the electrode plate 15 and the extended sealing body 50 overlap.

The cutting step S14 is a step of cutting the outer peripheral edge portion of the expansion sealing body 50 after the welding step S13. In the cutting step S14, the expansion portion 50a is cut off as the edge portion of the expansion sealing body 50. As a result, the primary sealing body 21 of a desired size is formed. As shown in FIG. 6A, the extended sealing body 50 is cut along the cutting line CL2 at the edge corresponding to one short side 50b. The extended sealant 50 is cut along the cutting line CL3 at the edge corresponding to the other short side 50c. The extended sealing body 50 is cut along the cutting line CL4 at the edge corresponding to one long side 50d. The extended sealing body 50 is cut along the cutting line CL5 at the edge corresponding to the other long side 50e. In the cutting step S14, at least the edges corresponding to the long sides 50d and 50e are cut.

In the present embodiment, as shown in FIG. 7A, the cutting step S14 is performed individually for each expansion sealing body 50 before the electrode laminate forming step S2. In the cutting step S14, the expansion sealing body 50 is cut by the cutting tool 58. As a result, the expansion portion 50a of the expansion sealing body 50 is removed, and the primary sealing body 21 is formed. The cut end by the cutting tool 58 is the outer peripheral edge 21a of the primary sealing body 21. At the time of cutting, the alignment is performed so that the dimension between the electrode plate 15 and the outer peripheral edge 21a becomes a specified dimension and the outer peripheral edge and the outer peripheral edge 21a of the electrode plate 15 are parallel to each other.

The type of cutting tool 58 is not particularly limited. For example, the cutting tool 58 may be a punching type cutting tool that cuts the cutting lines CL2 to CL5 at the same time. Alternatively, the cutting tool 58 may be a cutting tool that simultaneously cuts the cutting lines CL2 and CL3 parallel to each other and simultaneously cuts the cutting lines CL4 and CL5 at different timings. Alternatively, the cutting tool 58 may be a cutting tool that individually cuts the cutting lines CL2 to CL5.

The electrode laminate forming step S2 is a step of forming the electrode laminate 11 by laminating a plurality of bipolar electrodes 14 in a state where the primary sealing body 21 is welded. As shown in FIG. 8, each bipolar electrode 14 of the electrode laminate 11 is positioned by the positioning member 66. The positioning member 66 is a member extending in the stacking direction and comes into contact with the outer peripheral edge 21a of the primary sealing body 21 in each stage. Here, the positioning member 66 is provided for each of the long side and the short side of the primary sealing body 21.

The sealing body forming step S3 is a step of forming the sealing body 12 on the side surface 11a of the electrode laminated body 11 (see FIG. 2). In the sealing body forming step S3, the electrode laminate 11 is arranged in the injection molding die. The resin is injected into the mold, and the space between the mold and the electrode laminate 11 is filled with the resin. As a result, the secondary sealing body 22 is formed so as to surround the primary sealing body 21, and the sealing body 12 is provided on the side surface 11a of the electrode laminated body 11. As a result, the process shown in FIG. 4 is completed.

Next, the operation and effect of the manufacturing method of the power storage device 1 according to the present embodiment will be described.

First, as a comparative example, a case where an unexpanded primary sealing body 21 is formed in the primary sealing body forming step S11 will be described. In the welding step S13, the bipolar electrode 14 on which the primary sealing body 21 is laminated is conveyed to the welding machine. However, since the primary sealing body 21 is made of a soft material, the shape of the primary sealing body 21 may be deformed during transportation. For example, as shown by the virtual line in FIG. 8A, the outer peripheral edge 21a and the inner peripheral edge 21b of the primary sealing body 21 are deformed so as to protrude toward the inner peripheral side. When the outer peripheral edge 21a is deformed to the inner peripheral side, as shown by a virtual line in FIG. 8B, the outer peripheral edge 21a of a part of the primary sealing bodies 21 is the outer peripheral edge 21a of the other primary sealing body 21. Placed inside. In this case, there arises a problem that a part of the primary encapsulant 21 does not melt with the secondary encapsulant 22 and liquid entanglement occurs. Further, when the inner peripheral edge 21b is deformed to the inner peripheral side, the internal space formed on the inner peripheral side of the primary sealing body 21 in the electrode laminated body 11 becomes narrow. In this case, there arises a problem that the pressure rises due to the generation of a small amount of gas in the internal space. In this way, the quality of the power storage device 1 may be affected.

On the other hand, in the method of manufacturing the power storage device 1 according to the present embodiment, the primary encapsulant 21 is laminated and pressed along the edge 15c of the electrode plate 15 to press the primary encapsulant 21 against the electrode plate 15. The welding step S13 is provided. When a plurality of bipolar electrodes 14 are laminated, such a primary sealing body 21 seals between the bipolar electrodes 14. Here, the method for manufacturing the power storage device 1 includes a cutting step S14 for cutting at least a part of the outer peripheral edge portion of the extended sealing body 50 after the welding step S13. In this case, the expansion sealing body 50 is cut from the expansion portion 50a, which is the outer peripheral edge portion, in a state of being welded to the electrode plate 15 by welding. That is, since the expansion portion 50a of the expansion sealing body 50 is cut in a state of being positioned with respect to the electrode plate 15, the primary sealing body 21 having an outer peripheral edge 21a having a desired shape can be formed. .. Further, the expansion sealing body 50 before cutting is configured to be wider than the final primary sealing body 21 after cutting by the amount of the cutting allowance (that is, the expansion portion 50a). That is, the rigidity of the extended sealing body 50 before cutting can be increased. Therefore, since the deformation of the extended sealing body 50 before the welding step can be suppressed, the deformation of the inner peripheral edge 21b can also be suppressed. As described above, the quality of the power storage device 1 can be improved.

Further, the method for manufacturing the power storage device 1 further includes an electrode laminate forming step S2 for forming the electrode laminate 11 by laminating a plurality of bipolar electrodes 14 having the primary sealant 21 welded to the electrode plate 15. The cutting step S14 is performed individually for each extended sealing body 50 before the electrode laminate forming step S2. In this case, the positional relationship between the bipolar electrode 14 and the extended sealing body 50 at the time of cutting is accurately adjusted for each sheet. Therefore, the outer peripheral edge 21a of the primary sealing body 21 after each cutting is in a state of being accurately aligned with the bipolar electrode 14. Therefore, in the electrode laminate forming step S2, the positioning between the stacked bipolar electrodes 14 can be performed accurately.

Further, in the method of manufacturing the power storage device 1, the extended sealing body 50 is formed in a rectangular shape, has a pair of long sides 50d and 50e and a pair of short sides 50b and 50c, and in the cutting step S14, at least the long side 50d. , 50e, the edge corresponding to 50e is cut. The primary sealant 21 is easily deformed at a position corresponding to the long side. Therefore, in the cutting step S14, the easily deformable portion is cut, so that the above-mentioned effect can be remarkably obtained.

The present invention is not limited to the above-described embodiment. For example, in the above-described embodiment, as shown in FIG. 7A, the cutting step S14 was performed individually for each expansion sealing body 50 before the electrode laminate forming step S2. Instead, as shown in FIG. 7B, the cutting step may be collectively performed on the plurality of expanded sealing bodies 50 stacked after the electrode laminate forming step S. In this case, since the cutting is performed on the plurality of extended sealing bodies 50 at once, the number of cuttings can be reduced. In addition, the positions of the outer peripheral edges 21a of each primary sealing body 21 can be accurately aligned. Therefore, the yield when forming the secondary sealing body 22 can be improved. In the method of FIG. 7B, the alignment in the laminated body forming step S2 is performed with reference to the outer peripheral edge of the extended sealing body 50. On the other hand, in the method of FIG. 7A, the alignment in the laminate forming step S2 is performed with reference to the outer peripheral edge 21a that has been accurately aligned with the bipolar electrode 14. Therefore, the method of FIG. 7A can further improve the positional accuracy between the bipolar electrodes 14 in the electrode laminate 11 as compared with that of FIG. 7B.

In the above-described embodiment, the expansion portion is provided on both the long side and the short side of the sealed body, and the expansion portion is cut. Instead of this, an extension may be provided and cut only on the long side. In this case, the expansion portion is not provided on the short side, and the outer peripheral edge of the final primary sealing body is formed at the stage of the welding step S13. It should be noted that the extension portion may be provided only on the short side.

1 ... power storage device, 14 ... bipolar electrode, 15 ... electrode plate, 15a ... one side, 15b ... other side, 21 ... primary encapsulant (encapsulant), 50 ... extended encapsulant (encapsulant), 50a … Expansion part (outer peripheral part).

Claims (3)

A preparatory step for preparing a bipolar electrode having a rectangular electrode plate having a positive electrode formed on one surface and a negative electrode formed on the other surface.
By laminating the encapsulants along the edges of each side of the electrode plate, the portion overlapping the edge portion of the electrode plate and the outer peripheral edge of the electrode plate when viewed from the stacking direction of the encapsulant. A laminating step of arranging the sealing body so as to have a portion protruding to the outer peripheral side.
A welding step of welding the sealing body to the edge portion of the electrode plate by hot-pressing the overlapping portion of the electrode plate and the sealing body.
A method for manufacturing a power storage device, comprising: after the welding step, a cutting step of cutting at least a part of the protruding portion of the frame-shaped sealing body welded to the edge portion of the electrode plate. Further provided is an electrode laminate forming step of forming an electrode laminate by alternately laminating a plurality of the bipolar electrodes and separators in which the sealant is welded on the electrode plate.
The method for manufacturing a power storage device according to claim 1, wherein the cutting step is individually executed for each of the sealed bodies before the electrode laminate forming step. Said cutting step, said protruding portion corresponding to the long side even without less of the sealing body in a rectangular frame shape having a short side pair of long sides and a pair of welded to the edges of the rectangular electrode plate The method for manufacturing a power storage device according to claim 1 or 2, which is disconnected.

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