JP2019192589A - Manufacturing method for power storage module - Google Patents

Abstract

To provide a manufacturing method for a power storage module, by which a power storage module can appropriately be manufactured by hindering molding failure of a sealing body.SOLUTION: A manufacturing method for a power storage module 4 formed by providing a seating body 12 on an outer edges of a rectangular electrode stack 11 in which a plurality of bipolar electrodes 14 are stacked, comprises: an arrangement step in which the electrode stack 11 is arranged in a metal mold; and a molding step in which resin P is injected into the metal mold, thereby molding the sealing body 12 from the resin over all the outer edges of the electrode stack 11, the molding step including molding resin by injecting the resin P from a corner position of the sealing body 12.SELECTED DRAWING: Figure 8

Description

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

  Conventionally, as a method for manufacturing a power storage module, for example, as described in Japanese Patent Application Laid-Open No. 2007-128792, a laminate in which a separator is disposed between a positive electrode and a negative electrode is created, and the laminate is wrapped with a laminate film. A device is known in which the periphery is molded by resin molding and sealed.

JP 2007-128792 A

  In such a method for manufacturing a power storage module, there is a risk of forming defects during the manufacture of the power storage module. For example, when a sealing body is provided by resin molding around a rectangular laminate, sink marks or voids may occur at the corners of the sealing body. More specifically, as shown in FIG. 12, when a sealing body is formed around the laminate 101 by resin molding, the flowing direction of the molten resin 103 changes at the corners of the molding region 102 of the sealing body. Therefore, shearing heat is generated between the flowing resin 103 and the mold 104. Thereby, it is considered that the resin 103 is locally heated at the corners, and the subsequent cooling increases the amount of shrinkage compared to other parts, resulting in poor molding of the sealing body.

  Then, an object of this invention is to provide the manufacturing method of the electrical storage module which can suppress the shaping | molding defect of a sealing body and can manufacture an electrical storage module appropriately.

  That is, in the method for manufacturing a power storage module according to the present invention, a plurality of bipolar electrodes are stacked to produce a stacked body having a rectangular cross section perpendicular to the stacking direction, and a sealing body is attached to the outer edge of the stacked body as viewed from the stacking direction. In the manufacturing method of the storage module configured to be provided, an arrangement step of arranging the laminated body inside the mold, and a resin is injected into the mold and sealed over the entire periphery of the outer edge viewed from the lamination direction of the laminated body. And a molding step of resin-molding the stationary body. In the molding step, resin is injected from the position of the rectangular corner of the molding region of the sealing body to perform resin molding. According to this method for manufacturing an electricity storage module, when the sealing body is resin-molded on the outer edge of the laminate, the resin flow direction is greatly changed by injecting the resin from the corners of the sealing body. Resin molding can be performed without any problem. For this reason, the manufacturing defect of a sealing body can be suppressed and manufacture of an electrical storage module can be performed appropriately.

  Further, in the above-described method for manufacturing the power storage module, in the molding step, the resin is injected from a plurality of positions in the molding region of the sealing body including the corner positions, and the same amount of resin is obtained from each of the plurality of positions. May be injected to form a sealing body. In this case, the resin can be smoothly flowed in the mold by injecting the same amount of resin from each of the plurality of positions and molding the sealing body in the molding step. Thereby, the shaping | molding defect of a sealing body is suppressed and manufacture of an electrical storage module can be performed appropriately.

  Further, in the above-described method for manufacturing the power storage module, in the molding step, the resin is injected from a plurality of positions in the molding region of the sealing body including the corner positions, and the resin is injected at a plurality of positions where the resin is injected. The distance between the positions may be the same. In this case, since the distance between the positions where the resin is injected is the same, the resin injected from each position can be smoothly flowed and molded. Thereby, the shaping | molding defect of a sealing body is suppressed and manufacture of an electrical storage module can be performed appropriately.

  Furthermore, in the above-described method for manufacturing an electricity storage module, in the molding step, the resin is injected from a position other than the position of the corner and the position of the corner, and before the injection of the resin at a position other than the position of the corner You may inject | pour resin of the position of a corner | angular part. In this case, since the resin injection at the corner portion is performed first, the flow of the resin injected from the corner portion is suppressed from being disturbed. Therefore, the flow of the resin around the corner is smooth, and the occurrence of molding defects of the sealed body is suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, the shaping | molding defect in resin molding of a sealing body can be suppressed, and manufacture of an electrical storage module can be performed appropriately.

It is a schematic sectional drawing of the electrical storage apparatus using the electrical storage module which concerns on embodiment of this invention. It is a schematic sectional drawing which shows the internal structure of an electrical storage module. It is a top view of the bipolar electrode which comprises the electrical storage module of FIG. FIG. 3 is a plan view of a negative electrode termination electrode shown in FIG. 2. It is a top view of the bipolar electrode and negative electrode termination electrode which were mutually laminated | stacked. It is a flowchart which shows each process of the manufacturing method of the electrical storage module which concerns on this embodiment. It is a process outline figure of resin molding in a manufacturing method of an electrical storage module concerning this embodiment. It is explanatory drawing of the gate used for the formation process in the manufacturing method of an electrical storage module. It is explanatory drawing of the formation process in the manufacturing method of an electrical storage module. It is explanatory drawing of the position of the gate used for a formation process. It is a comparative example of the position of the gate used for a formation process. It is explanatory drawing of background art.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same or an equivalent part, and the overlapping description is abbreviate | omitted.

  First, prior to the description of the method for manufacturing the power storage module according to the present embodiment, a power storage module and a power storage device using the power storage module will be described.

  FIG. 1 is a schematic cross-sectional view of a power storage device using a power storage module. The power storage device 1 shown in FIG. 1 is an example of a power storage device using the power storage module 4 according to the present embodiment, and is used as a battery for various vehicles such as forklifts, hybrid vehicles, and electric vehicles. The power storage device 1 is constrained to a module stack 2 including a plurality of stacked power storage modules 4 and to the module stack 2 in the stacking direction (here, electrode stacking direction D in an electrode stack 11 described later). And a restraining member 3 for applying a load.

  The module laminate 2 includes a plurality (here, three) of power storage modules 4 and a plurality (here, four) of conductive plates 5. The power storage module 4 is a bipolar battery and has a rectangular shape when viewed in the stacking direction D. The power storage module 4 is, for example, a secondary battery such as a nickel hydride secondary battery or a lithium ion secondary battery, or an electric double layer capacitor. In the following description, a nickel metal hydride secondary battery is illustrated.

  The power storage modules 4 adjacent to each other in the stacking direction D are electrically connected via the conductive plate 5. The conductive plates 5 are respectively disposed between the storage modules 4 adjacent to each other in the stacking direction D and outside the stacking direction D of the 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 stacking direction D of the power storage module 4 located at the stacking end. A negative electrode terminal 7 is connected to the other conductive plate 5 disposed outside the stacking direction D of the power storage module 4 located at the stacking end. For example, the positive electrode terminal 6 and the negative electrode terminal 7 are drawn from the edge of the conductive plate 5 in a direction crossing the stacking direction D. The power storage device 1 is charged and discharged by the positive electrode terminal 6 and the negative electrode terminal 7.

  Inside the conductive plate 5, a plurality of flow paths 5 a for circulating a refrigerant such as air are provided. For example, the flow path 5a extends along a direction intersecting (orthogonal) with each other in the stacking direction D and the lead-out direction of the positive electrode terminal 6 and the negative electrode terminal 7. In addition to the function as a connection member for electrically connecting the power storage modules 4 to each other, the conductive plate 5 serves as a heat dissipation plate that dissipates heat generated in the power storage module 4 by circulating a refrigerant through these flow paths 5a. It has both functions. In the example of FIG. 1, the area of the conductive plate 5 viewed from the stacking direction D 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 It may be the same as the area or may be larger than the area of the power storage module 4.

  The restraining member 3 includes a pair of end plates 8 that sandwich the module laminate 2 in the stacking direction D, and fastening bolts 9 and nuts 10 that fasten the end plates 8 together. The end plate 8 is a rectangular metal plate having an area that is slightly larger than the areas of the power storage module 4 and the conductive plate 5 as viewed from the stacking direction D. On the inner side surface in the stacking direction D of the end plate 8 (the surface facing the module stacked body 2 side), a film F having electrical insulation is provided. The film F insulates the end plate 8 from the conductive plate 5.

  The end plate 8 is provided with an insertion hole 8 a at an edge on the outer peripheral side with respect to a portion overlapping the module stack 2 in the stacking direction D. The fastening bolt 9 is passed from the insertion hole 8 a of one end plate 8 toward the insertion hole 8 a of the other end plate 8, and at the tip of the fastening bolt 9 protruding from the insertion hole 8 a of the other end plate 8. The nut 10 is screwed together. As a result, the power storage module 4 and the conductive plate 5 are sandwiched by the end plate 8 and unitized as the module stacked body 2, and a restraining load is applied to the module stacked body 2 in the stacking direction D.

  Next, the configuration of the power storage module 4 will be described in detail. FIG. 2 is a schematic cross-sectional view showing the internal configuration of the power storage module 4 shown in FIG. As shown in FIG. 2, the power storage module 4 has an electrode laminated body (laminated body) 11 formed by laminating a plurality of bipolar electrodes 14, and a resin sealing body 12 on the outer edge of the electrode laminated body 11. Is provided. The electrode stack 11 includes a separator 13 and a plurality of electrodes (a plurality of bipolar electrodes 14, a single negative electrode termination electrode 18, and a single electrode) stacked in the stacking direction D (first direction) via the separator 13. One positive terminal electrode 19). Here, the stacking direction D of the electrode stack 11 coincides with the stacking direction of the module stack 2. The electrode stack 11 has a side surface 11a extending in the stacking direction D. As an example, the side surface 11a is configured as a set of end surfaces (surfaces connecting the first surface 15a and the second surface 15b) of an electrode plate 15 described later.

  The bipolar electrode 14 includes an electrode plate 15, a positive electrode 16, and a negative electrode 17. The positive electrode 16 is provided on the first surface 15 a of the electrode plate 15. The negative electrode 17 is provided on the second surface 15 b opposite to the first surface 15 a of the electrode plate 15. The electrode plate 15 is made of a metal such as nickel or a nickel-plated steel plate, for example. As an example, the electrode plate 15 is a rectangular metal foil made of nickel. The electrode plate 15 includes a rectangular outer edge 15d as viewed from the stacking direction D.

  The positive electrode 16 is a positive electrode active material layer formed by applying a positive electrode active material to the electrode plate 15. An example of the positive electrode active material constituting the positive electrode 16 is nickel hydroxide. The positive electrode 16 includes a rectangular outer edge 16d when viewed from the stacking direction D. The negative electrode 17 is a negative electrode active material layer formed by applying a negative electrode active material to the electrode plate 15. As a negative electrode active material which comprises the negative electrode 17, a hydrogen storage alloy is mentioned, for example. The negative electrode 17 includes a rectangular outer edge 17d when viewed from the stacking direction D.

  In the present embodiment, the formation region of the negative electrode 17 on the second surface 15 b of the electrode plate 15 is larger than the formation region of the positive electrode 16 on the first surface 15 a of the electrode plate 15. That is, the outer edge 17 d of the negative electrode 17 is slightly larger than the outer edge 16 d of the positive electrode 16. The peripheral edge portion 15c of the electrode plate 15 has a rectangular frame shape and is an uncoated region where the positive electrode active material and the negative electrode active material are not coated. That is, the peripheral edge portion 15 c of the electrode plate 15 is a portion surrounding the positive electrode 16 and the negative electrode 17, as viewed from the stacking direction D, except for the region where the positive electrode 16 and the negative electrode 17 are formed. . Note that the surfaces of the bipolar electrode 14, the negative electrode termination electrode 18, and the positive electrode termination electrode 19 include a first surface 15 a and a second surface 15 b in the peripheral portion 15 c of the electrode plate 15, respectively.

  In the electrode stack 11, the positive electrode 16 of one bipolar electrode 14 faces the negative electrode 17 of another bipolar electrode 14 adjacent in the stacking direction D across the separator 13. In the electrode stack 11, the negative electrode 17 of one bipolar electrode 14 faces the positive electrode 16 of another bipolar electrode 14 adjacent in the stacking direction D across the separator 13.

  The negative electrode termination electrode 18 includes an electrode plate 15 and a negative electrode 17 provided on the second surface 15 b of the electrode plate 15. The negative electrode termination electrode 18 does not include the positive electrode 16. That is, the active material layer is not provided on the first surface 15a of the electrode plate 15 of the negative electrode termination electrode 18 (that is, the entire first surface 15a of the negative electrode termination electrode 18 is exposed). The negative electrode termination electrode 18 is disposed at one end in the stacking direction D so that the second surface 15 b faces the inner side of the electrode stack 11 in the stacking direction D (center side in the stacking direction D). The negative electrode 17 of the negative electrode termination electrode 18 is opposed to the positive electrode 16 of the bipolar electrode 14 at one end in the stacking direction D via the separator 13.

  The positive electrode termination electrode 19 includes an electrode plate 15 and a positive electrode 16 provided on the first surface 15 a of the electrode plate 15. The positive electrode termination electrode 19 does not include the negative electrode 17. That is, the active material layer is not provided on the second surface 15b of the electrode plate 15 of the positive electrode termination electrode 19 (that is, the entire second surface 15b of the positive electrode termination electrode 19 is exposed). The positive electrode termination electrode 19 is disposed at the other end in the stacking direction D so that the first surface 15 a faces the inside of the stacking direction D of the electrode stack 11. The positive electrode 16 of the positive electrode termination electrode 19 faces the negative electrode 17 of the bipolar electrode 14 at the other end in the stacking direction D via the separator 13.

  The conductive plate 5 is in contact with the first surface 15 a of the electrode plate 15 of the negative electrode termination electrode 18. The conductive plate 5 of the adjacent power storage module 4 is in contact with the second surface 15 b of the electrode plate 15 of the positive electrode termination electrode 19. The restraining load from the restraining member 3 is applied to the electrode laminate 11 from the negative terminal electrode 18 and the positive terminal electrode 19 via the conductive plate 5. That is, the conductive plate 5 is also a restraining member that applies a restraining load to the electrode laminate 11 along the stacking direction D.

  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), and a woven or non-woven fabric made of polypropylene, methylcellulose, or the like. The separator 13 may be reinforced with a vinylidene fluoride resin compound. The separator 13 is not limited to a sheet shape, and may be a bag shape.

  The sealing body 12 is made of, for example, an insulating resin. The sealing body 12 is provided along the side surface 11a of the electrode laminate 11 so as to surround the peripheral edge portion 15c. The sealing body 12 holds the peripheral edge portion 15c. The bipolar electrode 14 is provided with an intermediate resin portion 23. The intermediate resin portion 23 is provided along the outer edge of the bipolar electrode 14 and is provided over the entire circumference of the bipolar electrode 14. The intermediate resin portion 23 is provided to be joined to the outer edge of the electrode plate 15. An end portion of the intermediate resin portion 23 is joined to the sealing body 12. That is, the bipolar electrode 14 is joined to the sealing body 12 via the intermediate resin portion 23 and supported by the sealing body 12. The intermediate resin part 23 has a first intermediate resin part 231 and a second intermediate resin part 232. Details of the first intermediate resin portion 231 and the second intermediate resin portion 232 will be described later.

  FIG. 3 is a diagram showing the bipolar electrode 14 to which the intermediate resin portion 23 is welded when viewed from the stacking direction D. FIG. FIG. 4 is a view showing the negative electrode termination electrode 18 to which the negative electrode termination resin portion 24 is welded when viewed from the stacking direction D. FIG. 5 is a diagram showing the bipolar electrode 14 and the negative electrode termination electrode 18 when viewed from the stacking direction D. FIG. The bipolar electrode 14 and the negative electrode termination electrode 18 shown in FIG. 5 are laminated with each other, with the intermediate resin portion 23 and the negative electrode termination resin portion 24 being welded to each other.

  2 to 5, the intermediate resin portion 23 is a film having a predetermined thickness (length in the stacking direction D). The intermediate resin portion 23 has a rectangular frame shape when viewed from the stacking direction D, and is continuously provided over the entire circumference of the peripheral edge portion 15c of the bipolar electrode 14 as described above. The intermediate resin portion 23 includes a rectangular inner edge 23 c and a rectangular outer edge 23 d as viewed from the stacking direction D. The intermediate resin portion 23 is welded to the surface of the bipolar electrode 14 at least at the peripheral edge portion 15 c of the bipolar electrode 14. Specifically, the intermediate resin portion 23 is welded to the first surface 15a of the bipolar electrode 14 and joined to the bipolar electrode 14 in an airtight (liquid tight) manner.

  The intermediate resin part 23 has a first intermediate resin part 231 and a second intermediate resin part 232. The first intermediate resin portion 231 and the second intermediate resin portion 232 are laminated together along the lamination direction D. Each of the first intermediate resin portion 231 and the second intermediate resin portion 232 has a rectangular frame shape when viewed in the stacking direction D, and includes a rectangular inner edge and an outer edge. When viewed from the stacking direction D, the outer edge of the first intermediate resin portion 231 and the outer edge of the second intermediate resin portion 232 coincide with each other to form the outer edge 23 d of the intermediate resin portion 23.

  When viewed from the stacking direction D, the inner edge of the second intermediate resin portion 232 has a rectangular shape that is larger than the inner edge of the first intermediate resin portion 231. Thereby, a stepped portion 23 e is formed in the intermediate resin portion 23. The edge of the separator 13 is placed on the step portion 23e. The inner edge of the first intermediate resin portion 231 constitutes the inner edge 23 c of the intermediate resin portion 23. The first intermediate resin portion 231 is welded to the first surface 15 a of the bipolar electrode 14 and joined to the electrode plate 15. The second intermediate resin portion 232 is welded onto the first intermediate resin portion 231 and joined to the first intermediate resin portion 231.

  The negative electrode termination resin portion 24 is a film having a predetermined thickness (length in the stacking direction D). The negative electrode termination resin portion 24 has a rectangular frame shape when viewed from the stacking direction D, and is continuously provided over the entire circumference of the peripheral edge portion 15 c of the negative electrode termination electrode 18. The negative terminal resin portion 24 includes a rectangular inner edge 24 c and a rectangular outer edge 24 d when viewed from the stacking direction D. The negative electrode termination resin portion 24 is welded to the surface of the negative electrode termination electrode 18 at least at the peripheral edge portion 15 c of the negative electrode termination electrode 18. Specifically, the negative electrode termination resin portion 24 is welded to the first surface 15a of the negative electrode termination electrode 18 and joined to the negative electrode termination electrode 18 in an airtight (liquid tight) manner.

  The positive electrode termination resin portions 25 and 26 are films having a predetermined thickness (length in the stacking direction D). The positive electrode termination resin portions 25 and 26 have a rectangular frame shape when viewed from the stacking direction D, and are continuously provided over the entire circumference of the peripheral edge portion 15 c of the positive electrode termination electrode 19. The positive electrode termination resin portion 25 includes a rectangular inner edge 25 c and a rectangular outer edge 25 d when viewed from the stacking direction D. The positive electrode termination resin portion 25 is welded to the surface of the positive electrode termination electrode 19 at least at the peripheral edge portion 15 c of the positive electrode termination electrode 19. Specifically, the positive electrode termination resin portion 25 is welded to the first surface 15 a of the positive electrode termination electrode 19 and joined to the positive electrode termination electrode 19 in an airtight (liquid tight) manner.

  The positive electrode termination resin portion 25 has a first portion 251 and a second portion 252. The first portion 251 and the second portion 252 are stacked on each other along the stacking direction D. Each of the first portion 251 and the second portion 252 has a rectangular frame shape when viewed from the stacking direction D, and includes a rectangular inner edge and an outer edge. When viewed from the stacking direction D, the outer edge of the first portion 251 and the outer edge of the second portion 252 coincide with each other and constitute an outer edge 25 d of the positive electrode termination resin portion 25. When viewed from the stacking direction D, the inner edge of the second portion 252 has a rectangular shape that is slightly larger than the inner edge of the first portion 251. Thereby, a step portion 25 e is formed in the positive electrode termination resin portion 25. The edge of the separator 13 is placed on the step portion 25e. An inner edge of the first portion 251 constitutes an inner edge 25 c of the positive electrode termination resin portion 25. The first portion 251 is welded to the first surface 15 a of the positive electrode termination electrode 19 and joined to the electrode plate 15. The second portion 252 is welded onto the first portion 251 and joined to the first portion 251.

  The positive electrode termination resin portion 26 includes a rectangular inner edge 26 c and a rectangular outer edge 26 d when viewed from the stacking direction D. The positive electrode termination resin portion 26 is welded to the surface of the positive electrode termination electrode 19 at least at the peripheral edge portion 15 c of the positive electrode termination electrode 19. Specifically, the positive electrode termination resin portion 26 is welded to the second surface 15 b of the positive electrode termination electrode 19 and joined to the positive electrode termination electrode 19 in an airtight (liquid tight) manner.

  Each of the intermediate resin portion 23, the negative electrode termination resin portion 24, and the positive electrode termination resin portion 25 is welded to the first surface 15a by, for example, ultrasonic waves or heat. The end surface of the electrode plate 15 is not covered with the intermediate resin portion 23, the negative electrode termination resin portion 24, and the positive electrode termination resin portion 25 and is exposed. The inner end portions of the intermediate resin portion 23, the negative electrode termination resin portion 24, and the positive electrode termination resin portion 25 are located between the peripheral portions 15 c of the electrode plates 15 adjacent to each other in the stacking direction D, and the outer end portions The portion projects outward from the electrode plate 15 as viewed from the stacking direction D. Each of the intermediate resin portion 23, the negative electrode termination resin portion 24, and the positive electrode termination resin portion 25 is embedded in the second resin portion 22 at the outer end portion. The first resin portions 21 adjacent to each other along the stacking direction D are separated from each other.

  The sealing body 12 is formed between the bipolar electrodes 14 adjacent to each other along the stacking direction D, between the negative electrode termination electrode 18 and the bipolar electrode 14 adjacent to each other along the stacking direction D, and along the stacking direction D. The space between the positive electrode termination electrode 19 and the bipolar electrode 14 adjacent to each other is sealed. As a result, the internal space V partitioned between the bipolar electrodes 14, between the negative electrode termination electrode 18 and the bipolar electrode 14, and between the positive electrode termination electrode 19 and the bipolar electrode 14 is hermetically (liquid-tight) partitioned. Is formed. In the internal space V, an electrolytic solution (not shown) made of an alkaline aqueous solution such as an aqueous potassium hydroxide solution is accommodated. That is, the first resin portion 21 is for forming the internal space V in which the electrolytic solution is accommodated between the electrodes adjacent along the stacking direction D and sealing the internal space V. The electrolytic solution is impregnated in the separator 13, the positive electrode 16, and the negative electrode 17.

  The sealing body 12 is, for example, an insulating resin and can be made of polypropylene (PP), polyphenylene sulfide (PPS), modified polyphenylene ether (modified PPE), or the like.

  Next, the relative relationship between the units will be described in detail. The inner side refers to the center side of the power storage module 4 when viewed from the stacking direction D. The outside refers to a side away from the center of the power storage module 4 when viewed from the stacking direction D. In the bipolar electrode 14, the negative electrode 17 is slightly smaller than the electrode plate 15. That is, the outer edge 17 d of the negative electrode 17 is located inside the outer edge 15 d of the electrode plate 15. The positive electrode 16 is slightly smaller than the negative electrode 17. That is, the outer edge 16 d of the positive electrode 16 is located inside the outer edge 17 d of the negative electrode 17. The outer edge 23 d of the intermediate resin portion 23 is located outside the outer edge 15 d of the electrode plate 15. The inner edge 23 c of the intermediate resin portion 23 is located between the outer edge 15 d of the electrode plate 15 and the outer edge 17 d of the negative electrode 17.

  The intermediate resin portion 23 is welded to the surface of the bipolar electrode 14 (here, the first surface 15a of the bipolar electrode 14) in the first area 15e (the hatched region in FIG. 3). In other words, the first area 15 e is an area where the intermediate resin portion 23 is welded on the first surface 15 a of the bipolar electrode 14, and has a rectangular frame shape by the outer edge 15 d of the electrode plate 15 and the inner edge 23 c of the intermediate resin portion 23. This is an area defined in

  In the negative electrode termination electrode 18, the negative electrode 17 is slightly smaller than the electrode plate 15. That is, the outer edge 17 d of the negative electrode 17 is located inside the outer edge 15 d of the electrode plate 15. The positive electrode 16 is slightly smaller than the negative electrode 17. That is, the outer edge 16 d of the positive electrode 16 is located inside the outer edge 17 d of the negative electrode 17. The outer edge 24 d of the negative electrode termination resin portion 24 is located outside the outer edge 15 d of the electrode plate 15. The inner edge 24 c of the negative electrode termination resin portion 24 is located inside the outer edge 16 d of the positive electrode 16. That is, the negative electrode termination resin portion 24 extends so as to overlap the positive electrode 16.

  The negative electrode termination resin portion 24 is welded to the surface of the negative electrode termination electrode 18 (here, the first surface 15a of the negative electrode termination electrode 18) in the second area 15f (the hatched region in FIG. 4). In other words, the second area 15 f is an area where the negative electrode termination resin portion 24 is welded on the first surface 15 a of the negative electrode termination electrode 18, and is formed by the outer edge 15 d of the electrode plate 15 and the inner edge 24 c of the negative electrode termination resin portion 24. This is an area defined as a rectangular frame.

  The outer edges 15d of the electrode plate 15 of the bipolar electrode 14 and the negative electrode termination electrode 18 coincide with each other. The outer edges 17d of the negative electrodes 17 of the bipolar electrode 14 and the negative electrode termination electrode 18 are coincident with each other. The outer edge 23d of the intermediate resin portion 23 and the outer edge 24d of the negative electrode termination resin portion 24 are coincident with each other. The inner edge 24 c of the negative electrode termination resin portion 24 is located inside the inner edge 23 c of the intermediate resin portion 23. That is, the second area 15f is larger than the first area 15e. That is, in all cross sections along the stacking direction D, the length of the second area 15f (rectangular frame width) is larger than the length of the first area 15e (rectangular frame width) (see FIG. 2). ). That is, the distance between the outer edge 15d of the electrode plate 15 of the negative electrode termination electrode 18 and the inner edge 24c of the negative electrode termination resin portion 24 over the entire circumference of the electrode laminate 11 when viewed from the lamination direction D is the electrode plate of the bipolar electrode 14 The distance between the 15 outer edges 15 d and the inner edge 23 c of the intermediate resin portion 23 is larger.

  The positive electrode termination resin portion 25 is welded to the surface of the positive electrode termination electrode 19 (here, the first surface 15a of the positive electrode termination electrode 19) in the first area 15g. In other words, the first area 15g is an area where the positive electrode termination resin portion 25 on the first surface 15a of the positive electrode termination electrode 19 is welded, and is formed by the outer edge 15d of the electrode plate 15 and the inner edge 25c of the positive electrode termination resin portion 25. This is an area defined as a rectangular frame. The positive electrode termination resin portion 26 is welded to the surface of the positive electrode termination electrode 19 (here, the second surface 15 b of the positive electrode termination electrode 19) and joined to the positive electrode termination electrode 19.

  Next, a method for manufacturing the power storage module 4 according to this embodiment will be described.

  FIG. 6 is a flowchart showing a manufacturing process of the power storage module 4. As shown in FIG. 6, as the storage module 4, first, the electrode laminate 11 is manufactured (S <b> 10). The electrode stack 11 is manufactured by stacking a plurality of bipolar electrodes 14 in a stacked manner. The bipolar electrode 14 is previously attached with an intermediate resin portion 23 and the like before being laminated. In addition to the bipolar electrode 14, a negative electrode termination electrode 18 and a positive electrode termination electrode 19 are also laminated on the electrode laminate 11.

  Next, the sealing body 12 is molded (S12). This forming step is a step of resin-molding the sealing body 12 on the outer edge of the electrode laminate 11. For example, injection molding is performed using the electrode laminate 11 as an insert member, and the sealing body 12 is molded around the electrode laminate 11. Details of the molding process will be described later.

  FIG. 7 is a process schematic diagram of resin molding of the sealing body 12 in the manufacture of the power storage module 4. The power storage module 4 is manufactured by resin-molding the sealing body 12 on the outer edge of the electrode laminate 11. FIG. 7A is a diagram showing an arrangement process of the electrode laminate 11. That is, the electrode laminated body 11 is arrange | positioned in the metal mold | die 91 as an insert member. The electrode laminate 11 is configured by laminating a plurality of bipolar electrodes 14 and is manufactured in advance before resin molding. The mold 91 is a fixed mold, and the electrode stack 11 is disposed at a predetermined position of the mold 91.

  7B and 7C are explanatory views of a molding process for resin molding the sealing body 12 on the outer edge of the electrode laminate 11. As shown in FIG. 7B, mold clamping is performed, and the mold 92 is joined to the mold 91. The mold 92 is a movable mold, and can be moved toward and away from the mold 91. A cavity portion (cavity) 93 is formed in the inside where the mold 91 and the mold 92 are joined. The cavity 93 is a molding region of the sealing body 12. That is, the sealing body 12 is formed by pouring the resin P into the hollow portion 93. The resin P is injected into the cavity 93 from the position of the corner 93a of the sealing body 12, and resin molding is performed. The resin P is injected into the cavity 93 through the gate 94.

  FIG. 8 is an explanatory diagram of the position of the gate 94 and shows a cross section of the die 91 in a direction (VIII-VIII in FIG. 7) perpendicular to the stacking direction of the electrode stack 11. As shown in FIG. 8, a cavity 93 is formed in the mold 91 with a predetermined width over the entire circumference of the outer edge of the electrode stack 11. Gates 94 are formed at a plurality of positions in the cavity 93. The gate 94 is an inlet for the resin P into the cavity 93. A plurality of gates 94 are formed in a mold 92 not shown in FIG. A part of the plurality of gates 94 is formed in the corner 93a of the cavity 93 (molded region of the sealing body 12). In FIG. 8, one gate 94 is formed at each of four corners 93a of the cavity 93 formed in a rectangular frame shape. Two gates 94 are formed on the long side of the cavity portion 93, and one gate 94 is formed on the short side of the cavity portion 93. In some cases, the gates 94 are formed only at the corners 93a, or the long side and short side gates 94 are formed in a number different from that described above.

  Further, when the resin molding of the sealing body 12 is performed, the injection amount of the resin P injected from each gate 94 may be the same. In this case, in the molding process, the same amount of resin P is injected from each of the gates 94 and the sealing body 12 is molded, so that the resin P can flow smoothly in the molds 91 and 92. In other words, when the resin molding of the sealing body 12 is performed, by making the amount of the resin P that each gate 94 is responsible for, the injection of the resin P in each gate 94 is completed almost simultaneously, and the flow of the resin P is not disturbed. It will be smooth. Thereby, generation | occurrence | production of the shaping | molding defect of the sealing body 12 is suppressed, and manufacture of the electrical storage module 4 can be performed appropriately. Note that the same injection amount here includes substantially the same injection amount. As long as the injection amount is such that the resin P can flow smoothly, the injection amount may not be the same and may be approximately the same.

  Further, when the sealing body 12 is resin-molded, the distance d between the adjacent gates 94 may be the same. As shown in FIG. 8, the distance d between the gate 94 and the gate 94 is made the same, and the resin P injected from the gate 94 is smoothly formed by injecting the resin P from the position of the gate 94 and molding. It can flow and mold. For example, as shown in FIG. 9, the resin P flows in a preset direction, the flow of the resin P is prevented from being disturbed, and the resin molding can be performed stably. Thereby, generation | occurrence | production of the shaping | molding defect of the sealing body 12 is suppressed, and manufacture of the electrical storage module 4 can be performed appropriately. Here, the same distance includes almost the same distance. As long as the resin P can flow smoothly, the distance may not be the same, but may be substantially the same.

  Further, the position of the gate 94 formed in the corner portion 93a may be a position outside the center position in the width direction, not the center position in the width direction of the cavity portion 93 (molding region). For example, as shown in FIG. 10, in the cavity 93 formed in a rectangular shape with a predetermined width along the outer edge of the electrode laminate 11, a gate 94 is formed at a position outside the center of the corner 93a. That is, the gate 94 is formed at a position closer to the outer edge than the inner edge in the corner 93a of the cavity 93. In this case, when the resin P is injected from the gate 94 of the corner portion 93a into the cavity portion 93, the resin P smoothly flows from the corner portion 93a to the molding region extending in two directions. On the other hand, as shown in FIG. 11, when the gate 94 is formed at the center position of the corner 93a, when the resin P is injected from the gate 94 of the corner 93a into the cavity 93, the corner 93a. Resin P that flows outward is produced. For this reason, the resin P does not smoothly flow from the corner portion 93a to the molding region extending in two directions, and the flow of the resin P is disturbed, which may cause molding defects.

  Furthermore, when resin molding of the sealing body 12 is performed, the injection start timing of the resin P in the gate 94 at the corner 93a and the other gate 94 may be different. That is, a gate opening / closing mechanism that opens and closes the gate 94 may be provided to control the timing of starting the injection of the resin P in the gate 94. For example, the injection of the resin P for the gate 94 at the corner 93a is performed prior to the injection of the resin P for the gate 94 other than the corner 93a. In this case, the injection of the resin P is started at an early timing from the gate 94 at the corner 93a. Thereby, the disturbance of the flow of the resin P in the vicinity of the corner portion 93a is suppressed, and a smooth flow of the resin P around the corner portion 93a is ensured. Therefore, generation | occurrence | production of the shaping | molding defect of the sealing body 12 in the corner | angular part 93a can be suppressed.

  Then, as shown in FIG. 7C, after filling the entire cavity 93 with the resin P, the resin P is cooled while applying pressure to the resin P for a predetermined time. Thereby, the sealing body 12 is shape | molded.

  Then, mold opening is performed to separate the mold 92 from the mold 91. Thereafter, the molded product in which the sealing body 12 is formed on the outer edge of the electrode laminate 11 is taken out from the mold 91 and unnecessary parts of the resin P are cut off, whereby the production of the power storage module 4 is completed.

  As described above, according to the method for manufacturing the power storage module 4 according to the present embodiment, when the sealing body 12 is resin-molded on the outer edge of the electrode laminate 11, the corners 93a of the molding region of the sealing body 12 are formed. By injecting the resin P from the position, resin molding can be performed without greatly changing the flow direction of the resin P. For this reason, the shaping | molding defect of the sealing body 12 is suppressed and manufacture of an electrical storage module can be performed appropriately. For example, as shown in FIG. 9, the flow path of the resin P can be made linear by injecting the resin P from the position of the corner portion 93 a of the molding region of the sealing body 12. For this reason, generation | occurrence | production of the molding defect by the change of the flow path of resin P is suppressed, and manufacture of an electrical storage module can be performed appropriately.

  Further, in the method for manufacturing the power storage module 4 according to the present embodiment, by molding the sealing body 12 by injecting the same amount of resin P from each of the plurality of gates 94 in the molding process of the sealing body 12, The resin P can smoothly flow in the molds 91 and 92. Thereby, the shaping | molding defect of the sealing body 12 is suppressed and manufacture of the electrical storage module 4 can be performed appropriately.

  Moreover, in the manufacturing method of the electrical storage module 4 according to the present embodiment, the distance between the gate 94 for injecting the resin P and the gate 94 is the same, so that the resin P injected from the position of each gate 94 can be obtained. It can flow smoothly and be molded. Thereby, the shaping | molding defect of the sealing body 12 is suppressed and manufacture of the electrical storage module 4 can be performed appropriately.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment.

  For example, in the above-described embodiment, the case of using the power storage device 1 in which the power storage modules 4 are stacked as illustrated in FIG. 1 has been described, but the power storage modules 4 may be used in different structures or formats. Further, in the above-described embodiment, the case where the power storage module 4 is used as a battery of various vehicles such as a forklift, a hybrid vehicle, and an electric vehicle has been described, but may be used for other purposes.

  DESCRIPTION OF SYMBOLS 4 ... Power storage module, 11 ... Electrode laminated body (laminated body), 12 ... Sealed body, 14 ... Bipolar electrode, 15 ... Electrode plate, 15a ... 1st surface, 15b ... 2nd surface, 15c ... Peripheral part, 16 ... Positive electrode, 17 ... negative electrode, 18 ... negative electrode termination electrode, 23 ... intermediate resin part, 24 ... negative electrode termination resin part, 15e ... first area, 15f ... second area, 91 ... mold, 92 ... mold, 93 ... cavity Part (molding region), 93a ... corner, 94 ... gate, D ... stacking direction, d ... distance, P ... resin.

Claims (4)

In a method for manufacturing a power storage module configured by stacking a plurality of bipolar electrodes to produce a stacked body having a rectangular cross section perpendicular to the stacking direction, and providing a sealing body on an outer edge of the stacked body viewed from the stacking direction ,
An arranging step of arranging the laminate inside the mold;
A molding step of injecting a resin into the mold and resin-molding the sealing body over the entire circumference of the outer edge viewed from the stacking direction of the stack,
In the molding step, resin molding is performed by injecting the resin from the position of the rectangular corner of the molding region of the sealing body.
A method for manufacturing a power storage module. In the molding step, the resin is injected from a plurality of positions in the molding region of the sealing body including the corner portions, and the same amount of the resin is injected from each of the plurality of positions to seal the sealing. Molding the stop,
The manufacturing method of the electrical storage module of Claim 1. In the molding step, the resin is injected from a plurality of positions in the molding region of the sealing body including the corner portions, and the positions between adjacent positions in the plurality of positions where the resin is injected. The distance is the same,
The manufacturing method of the electrical storage module of Claim 1 or 2. In the molding step, the resin is injected from a position other than the corner position and the corner position, and the resin at the corner position is injected before the resin injection at a position other than the corner position. Do the injection,
The manufacturing method of the electrical storage module of Claim 1.

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