JP7103055B2 - 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 method for manufacturing a power storage module, for example, the technique described in Patent Document 1 is known. Patent Document 1 has a structure in which a plurality of bipolar electrodes having a positive electrode layer provided on one surface of a current collector and a negative electrode layer provided on the other surface of the current collector are laminated via an electrolyte layer. A bipolar battery including an electrode laminate and a resin group that covers the outside of the electrode laminate is described. When manufacturing such a bipolar battery, the electrode laminate is sealed by pouring the resin material constituting the resin group around the electrode laminate and solidifying the electrode laminate in a state where the electrode laminate is set in the mold. Stop.

Japanese Unexamined Patent Publication No. 2005-5163

As a method for manufacturing the power storage module as described above, a configuration is conceivable in which a resin material is poured around the electrode laminate in a state where the electrode laminate is constrained in the lamination direction of the bipolar electrodes by a pair of molding dies. By the way, the thickness of the electrode laminate may vary due to manufacturing tolerances of bipolar electrodes and the like. Therefore, when the electrode laminate is thin, the restraining load applied to the electrode laminate by the pair of molding dies becomes small. When the resin material is poured around the electrode laminate, the molding pressure due to the resin material is applied to the side surface of the electrode laminate, so that the electrode laminate may be deformed by the molding pressure when the restraining load is small.

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 the electrode laminate during injection molding.

The power storage module according to one aspect of the present invention includes an electrode laminate including a plurality of electrodes laminated along a first direction, and a plurality of primary seals provided on the peripheral edges of the electrode plates of the plurality of electrodes. And the secondary encapsulant provided around the plurality of primary encapsulants, and the primary encapsulant located at one end in the first direction of the electrode laminate among the plurality of primary encapsulants. It includes a first reinforcing member. The first reinforcing member is sandwiched between the primary sealing body and the secondary sealing body in the first direction.

In this power storage module, a first reinforcing member is provided on a primary sealing body located at one end in the first direction of the electrode laminate, and the first reinforcing member is a primary sealing body and a secondary sealing body in the first direction. It is sandwiched between the stationary body. When manufacturing this power storage module, after a primary encapsulant is formed on the peripheral edge of the electrode plates of a plurality of electrodes included in the electrode laminate, a secondary encapsulant is formed around the plurality of primary encapsulants. Is formed. The secondary encapsulant is formed by injecting a resin material around a plurality of primary encapsulants, for example, with the electrode laminates constrained in the lamination direction by a molding die. At this time, molding pressure is applied to the side surface of the electrode laminate. Since the primary encapsulant located at one end is provided with the first reinforcing member, it is possible to prevent the primary encapsulant from being rolled up by the molding pressure due to the interference of the first reinforcing member with the molding die. Can be done. As a result, it is possible to suppress the deformation of the electrode laminate during injection molding.

The power storage module may further include a second reinforcing member provided on another primary sealing body located at the other end in the first direction of the electrode laminate among the plurality of primary sealing bodies. The second reinforcing member may be sandwiched between another primary sealing body and the secondary sealing body in the first direction. In this case, since the second reinforcing member is provided on the other primary sealing body located at the other end, the second reinforcing member interferes with the molding die, so that the other primary sealing body is affected by the molding pressure. It is possible to suppress rolling up. As a result, it is possible to further suppress the deformation of the electrode laminate during injection molding.

The first reinforcing member may be made of metal. In this case, since the rigidity of the first reinforcing member is high, deformation of the first reinforcing member due to molding pressure is suppressed. As a result, it is possible to further suppress the primary encapsulant from rolling up due to the molding pressure, and it is possible to further suppress the deformation of the electrode laminate during injection molding.

The first reinforcing member may be integrated with the primary sealing body. In this case, since the joint strength between the first reinforcing member and the primary sealing body is high, deformation of the first reinforcing member due to molding pressure is suppressed. As a result, it is possible to further suppress the primary encapsulant from rolling up due to the molding pressure, and it is possible to further suppress the deformation of the electrode laminate during injection molding.

The method for manufacturing a power storage module according to another aspect of the present invention includes a step of preparing a plurality of electrodes each including an electrode plate, and forming a plurality of primary sealants on the peripheral edge of each electrode plate of the plurality of electrodes. A step, a step of forming an electrode laminate by laminating a plurality of electrodes along a first direction, and injection molding using a molding die around a plurality of primary seals provided on the electrode laminate. A step of forming a secondary sealing body is provided. The molding die includes a pressing portion for restraining the electrode laminate along the first direction. A reinforcing member is provided on the primary sealing body located at one end in the first direction of the electrode laminate among the plurality of primary sealing bodies. In the step of forming the secondary sealing body, the electrode laminate is arranged along the first direction by the molding die so that the pressing portion and the reinforcing member are arranged so as to face each other in the second direction intersecting the first direction. The secondary encapsulant is formed by injecting the resin material into the cavity formed by the molding die.

In this method of manufacturing a power storage module, a plurality of primary encapsulants are formed on the peripheral edge of each electrode plate of a plurality of electrodes, and secondary encapsulation is performed by injection molding using a molding die around the plurality of primary encapsulants. A seal is formed. The secondary sealant is formed by injecting a resin material into a cavity formed by the mold while the electrode laminate is restrained along the first direction by the mold. At this time, molding pressure is applied to the side surface of the electrode laminate. A reinforcing member is provided on the primary sealing body located at one end, and the reinforcing member is arranged so as to face each other in the second direction with the pressing portion of the molding die. Therefore, when the reinforcing member interferes with the pressing portion of the molding die, it is possible to prevent the primary sealing body from being rolled up by the molding pressure. As a result, it is possible to suppress the deformation of the electrode laminate during injection molding.

The reinforcing member may be formed while the primary encapsulant is welded to the electrode plate by hot pressing in the step of forming the plurality of primary encapsulants. In this case, since the formation of the primary sealing body and the formation of the reinforcing member are performed in the same process, the man-hours can be reduced.

According to the present invention, deformation of the electrode laminate during injection molding can be suppressed.

FIG. 1 is a schematic cross-sectional view showing a power storage device including a power storage module according to an embodiment. FIG. 2 is a schematic cross-sectional view showing the internal configuration of the power storage module shown in FIG. FIG. 3 is an enlarged schematic view of a main part showing the configuration of the sealing body of the power storage module shown in FIG. FIG. 4 is a process diagram showing a main process of the method for manufacturing the power storage module shown in FIG. FIG. 5 is a diagram for explaining the secondary molding step of FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same reference numerals are used for the same or equivalent elements, and duplicate description is omitted.

FIG. 1 is a schematic cross-sectional view showing a power storage device including a power storage module according to an embodiment. The power storage device 1 shown in FIG. 1 is used as a battery for various vehicles such as forklifts, hybrid vehicles, and electric vehicles. The power storage device 1 includes a module laminate 2 and a restraint member 3.

The module laminate 2 includes 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 a bipolar battery 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 and a lithium ion secondary battery, or an electric double layer capacitor. In the following description, a nickel-metal hydride secondary battery will be illustrated.

Two power storage modules 4 adjacent to each other in the stacking direction are electrically connected to each other via a conductive plate 5. The conductive plates 5 are arranged between two power storage modules 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 a conductive plate 5 arranged outside the power storage module 4 located at the lower end of the stack. A negative electrode terminal 7 is connected to a conductive plate 5 arranged outside the power storage module 4 located at the upper end of the stack. 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 the stacking direction. The positive electrode terminal 6 and the negative electrode terminal 7 charge and discharge the power storage device 1.

Inside the conductive plate 5, a plurality of flow paths 5a for passing a refrigerant such as air are provided. The flow path 5a extends along a direction intersecting (orthogonal) with, for example, the stacking direction and the drawing direction of the positive electrode terminal 6 and the negative electrode terminal 7. The conductive plate 5 has a function as a connecting member for electrically connecting two power storage modules 4 adjacent to each other in the stacking direction, and is generated in the power storage module 4 by circulating a refrigerant through these flow paths 5a. It also has a function as a heat sink that releases heat. 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 a member that applies a restraint load to the module laminate 2 in the stacking direction of the module laminate 2. The restraint member 3 includes a pair of end plates 8 that sandwich the module laminate 2 in the stacking direction, and a fastening bolt 9 and a nut 10 that fasten the pair of end plates 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 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 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 plate 8 to be unitized as the module laminate 2, and a restraining load is applied to the module laminate 2 in the stacking direction.

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 shown in FIG. As shown in FIG. 2, 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 has a plurality of separators 13, a plurality of bipolar electrodes 14, a negative electrode terminal electrode 18, and a positive electrode terminal electrode 19. In the present embodiment, the stacking direction D (first direction) of the electrode laminated body 11 coincides with the stacking direction of the module laminated body 2. The electrode laminate 11 has a side surface 11a extending in 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 fabric or a non-woven fabric made of polypropylene, methyl cellulose and the like. The separator 13 may be reinforced with a vinylidene fluoride resin compound. The separator 13 may have a bag shape.

The negative electrode terminal electrode 18, the plurality of bipolar electrodes 14, and the positive electrode terminal electrodes 19 (plurality of electrodes) are laminated in this order via the separator 13 along the stacking direction D. Each of the plurality of bipolar electrodes 14 includes an electrode plate 15, a positive electrode 16, and a negative electrode 17. 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 electrode plate 15 includes an upper surface 15a and a lower surface 15b opposite to the upper surface 15a. The peripheral 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.

The positive electrode 16 is provided on the upper surface 15a of the electrode plate 15. The positive electrode 16 is a positive electrode active material layer formed by applying a positive electrode active material to the upper surface 15a. Examples of the positive electrode active material constituting the positive electrode 16 include nickel hydroxide. The negative electrode 17 is provided on the lower surface 15b of the electrode plate 15. The negative electrode 17 is a negative electrode active material layer formed by applying a negative electrode active material to the lower surface 15b. 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 lower surface 15b of the electrode plate 15 is one size larger than the formation region of the positive electrode 16 on the upper surface 15a of the electrode plate 15.

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 D 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 D with the separator 13 interposed therebetween.

The negative electrode terminal electrode 18 is arranged at one end 11b of the electrode laminate 11 in the stacking direction D. The negative electrode terminal electrode 18 includes an electrode plate 15 and a negative electrode 17 provided on the lower 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 located at one end in the stacking direction D via the separator 13. One conductive plate 5 adjacent to the power storage module 4 is in contact with the upper surface 15a of the electrode plate 15 of the negative electrode terminal electrode 18.

The positive electrode terminal electrode 19 is arranged at the other end 11c on the side opposite to one end 11b of the electrode laminate 11 in the stacking direction D. The positive electrode terminal electrode 19 includes an electrode plate 15 and a positive electrode 16 provided on the upper surface 15a of the electrode plate 15. The positive electrode 16 of the positive electrode terminal electrode 19 faces the negative electrode 17 of the bipolar electrode 14 located at the other end of the stacking direction D via the separator 13. The other conductive plate 5 adjacent to the power storage module 4 is in contact with the lower surface 15b of the electrode plate 15 of the positive electrode terminal electrode 19.

FIG. 3 is an enlarged schematic view of a main part showing the configuration of the sealing body of the power storage module shown in FIG. The sealing body 12 shown in FIGS. 2 and 3 is formed in, for example, a rectangular cylinder. The sealing body 12 is formed of an insulating resin material. 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 hold the peripheral edge portion 15c of the electrode plate 15 on the side surface 11a of the electrode laminated body 11 extending in the stacking direction D and to surround the side surface 11a. The sealing body 12 seals between two bipolar electrodes 14 adjacent to each other in the stacking direction D.

The sealing body 12 has a plurality of primary sealing bodies 21, a secondary sealing body 22, a reinforcing member 25 (first reinforcing member), and a reinforcing member 26 (second reinforcing member). .. The primary sealing body 21 is continuously provided over the entire circumference (all sides) of the electrode plate 15 at the peripheral edge portion 15c (uncoated region) of the electrode plate 15. The primary sealing body 21 has an inner edge portion 21a and an outer edge portion 21b. The inner edge portion 21a overlaps with the electrode plate 15 when viewed from the stacking direction D. The outer edge portion 21b projects to the outside of the electrode plate 15 when viewed from the stacking direction D. At least a part of the inner edge portion 21a is airtightly bonded to the peripheral edge portion 15c of the electrode plate 15. The end surface on the outer edge portion 21b side is airtightly joined to the inner surface 22a of the secondary sealing body 22.

In the present embodiment, the sealing body 12 includes a plurality of primary sealing bodies 21A, a primary sealing body 21B, and a primary sealing body 21C (another primary sealing body) as the primary sealing body 21. Includes. Each primary sealing body 21A is provided on the upper surface 15a of the electrode plate 15 at the peripheral edge portion 15c of the bipolar electrode 14 or the positive electrode terminal electrode 19.

The primary sealing body 21A has a rectangular frame-shaped resin layer 23 arranged on the peripheral edge portion 15c of the electrode plate 15, and a rectangular frame-shaped resin layer 24 arranged on the resin layer 23. .. The primary sealant 21A is bonded to the upper surface 15a in the resin layer 23. The resin layer 23 and the resin layer 24 are continuous with each other at their outer peripheral edges. The facing surfaces of the resin layer 23 and the resin layer 24 are joined to each other by heat. In the present embodiment, the primary sealing body 21A is formed by folding back one resin film (sheet).

The outer edge 23a of the resin layer 23 coincides with the outer edge 24a of the resin layer 24 when viewed from the stacking direction D. The inner edge 23b of the resin layer 23 is located inside the electrode laminate 11 with respect to the inner edge 24b of the resin layer 24 when viewed from the stacking direction D. That is, the resin layer 23 includes an extending region 23c extending inside the electrode laminate 11 with respect to the resin layer 24, and a covering region 23d covered with the resin layer 24. The outer edge portion 13a of the separator 13 is arranged (placed) in the extending region 23c. The two electrode plates 15 adjacent to each other in the stacking direction D are kept in a state of being insulated from each other by the separator 13 and the primary sealant 21A.

The covering region 23d is arranged outside the extending region 23c. Seen from the stacking direction D, the outer edge of the separator 13 is located between the inner edge 23b of the resin layer 23 and the inner edge 24b of the resin layer 24. The inner edge of the covering region 23d (inner edge 24b of the resin layer 24) is located inside the electrode laminate 11 with respect to the outer edge of the electrode plate 15 when viewed from the stacking direction D.

The primary sealing body 21B is provided on the upper surface 15a of the electrode plate 15 at the peripheral edge portion 15c of the negative electrode terminal electrode 18. That is, the primary sealing body 21B is located at one end 11b of the electrode laminated body 11 among the plurality of primary sealing bodies 21. The primary sealant 21B has the same configuration as the primary sealant 21A except that the inner edge 23b of the resin layer 23 and the inner edge 24b of the resin layer 24 coincide with each other when viewed from the stacking direction D. have.

The primary sealing body 21C is provided on the lower surface 15b of the electrode plate 15 at the peripheral edge portion 15c of the positive electrode terminal electrode 19. That is, the primary sealing body 21C is located at the other end 11c of the electrode laminated body 11 among the plurality of primary sealing bodies 21. The primary sealing body 21C is formed in a single layer, and has a shape that wraps around from the lower surface 15b of the electrode plate 15 to the end surface of the electrode plate 15.

The secondary sealing body 22 is provided so as to surround the plurality of primary sealing bodies 21 from the outside. The secondary encapsulant 22 is provided around the electrode laminate 11 and the plurality of primary encapsulants 21 and constitutes an outer wall (housing) of the power storage module 4. The secondary sealing body 22 is formed by injection molding of a resin, and extends along the stacking direction D over the entire length of the electrode laminated body 11. The secondary sealing body 22 has a tubular shape (annular shape) extending with the stacking direction D as the axial direction. The secondary encapsulant 22 is welded (joined) to the end face of the primary encapsulant 21 on the outer edge portion 21b side by heat during injection molding, for example.

The secondary sealing body 22 has an upper end portion 22b located at one end in the stacking direction D and a lower end portion 22c located at the other end in the stacking direction D. The upper end portion 22b extends from the inner surface 22a toward the electrode laminate 11 and covers the outer edge portion of the upper surface of the primary sealing body 21B. The upper end portion 22b is continuously provided over the entire circumference of the primary sealing body 21B. The lower end portion 22c extends from the inner surface 22a toward the electrode laminated body 11 and covers the outer edge portion of the lower surface of the primary sealing body 21C. The lower end portion 22c is continuously provided over the entire circumference of the primary sealing body 21C.

The secondary encapsulant 22, together with the primary encapsulant 21, has two bipolar electrodes 14 adjacent to each other along the stacking direction D, and a negative electrode terminal 18 and a bipolar electrode 14 adjacent to each other along the stacking direction D. The space between the positive electrode terminal 19 and the bipolar electrode 14 adjacent to each other along the stacking direction D are sealed. As a result, an airtightly partitioned internal space V is formed between the two bipolar electrodes 14, between the negative electrode terminating electrode 18 and the bipolar electrode 14, and between the positive electrode terminating electrode 19 and the bipolar electrode 14. Has been done. Each internal space V contains an electrolytic solution (not shown) composed of an alkaline aqueous solution such as an aqueous potassium hydroxide solution. The electrolytic solution is impregnated in the separator 13, the positive electrode 16 and the negative electrode 17.

The reinforcing member 25 is provided on the upper surface of the primary sealing body 21B. The reinforcing member 25 is a rectangular frame-shaped member, and is continuously provided over the entire circumference (all sides) of the primary sealing body 21B. The reinforcing member 25 is separate from the primary sealing body 21B, and is made of, for example, metal. An example of the reinforcing member 25 is a metal foil such as a nickel foil having a roughened lower surface. The reinforcing member 25 is sandwiched between the primary sealing body 21B and the upper end portion 22b of the secondary sealing body 22 in the stacking direction D. Seen from the stacking direction D, the outer edge 25a of the reinforcing member 25 coincides with the outer edge 23a of the resin layer 23 of the primary sealing body 21B and the outer edge 24a of the resin layer 24 of the primary sealing body 21B. The inner edge 25b of the reinforcing member 25 is located outside the electrode laminate 11 with respect to the inner edge 23b of the resin layer 23 of the primary sealant 21B and the inner edge 24b of the resin layer 24 of the primary sealant 21B when viewed from the stacking direction D. It coincides with the inner edge of the upper end portion 22b of the secondary sealing body 22.

The reinforcing member 26 is provided on the lower surface of the primary sealing body 21C. The reinforcing member 26 is a rectangular frame-shaped member, and is continuously provided over the entire circumference (all sides) of the primary sealing body 21C. The reinforcing member 26 is separate from the primary sealing body 21C, and is made of, for example, metal. An example of the reinforcing member 26 is a metal foil such as a nickel foil having a roughened upper surface. The reinforcing member 26 is sandwiched between the primary sealing body 21C and the lower end portion 22c of the secondary sealing body 22 in the stacking direction D. Seen from the stacking direction D, the outer edge 26a of the reinforcing member 26 coincides with the outer edge of the primary sealing body 21C. The inner edge 26b of the reinforcing member 26 is located outside the electrode laminated body 11 with respect to the inner edge of the primary sealing body 21C and coincides with the inner edge of the lower end portion 22c of the secondary sealing body 22 when viewed from the stacking direction D. There is.

Next, a method of manufacturing the power storage module 4 will be described. FIG. 4 is a process diagram showing a main process of the method for manufacturing the power storage module shown in FIG. FIG. 5 is a diagram for explaining the secondary molding step of FIG. As shown in FIG. 4, first, a preparatory step S1 for preparing a plurality of bipolar electrodes 14, a negative electrode terminal electrode 18, and a positive electrode terminal electrode 19 is performed.

Subsequently, the primary molding step S2 for forming the primary sealing body 21 on the peripheral edge portion 15c of each electrode plate 15 of each of the bipolar electrode 14, the negative electrode terminal electrode 18, and the positive electrode terminal electrode 19 is performed. In the primary molding step S2, for example, the primary sealants 21A and 21B are welded to the upper surface 15a along the peripheral edge 15c of the electrode plate 15 by hot pressing, and are primary to the lower surface 15b along the peripheral edge 15c of the electrode plate 15. The sealing body 21C is welded.

Subsequently, the reinforcing step S3 is performed in which the reinforcing member 25 is formed on the primary sealing body 21B and the reinforcing member 26 is formed on the primary sealing body 21C. In the reinforcing step S3, the reinforcing member 25 is joined to the upper surface of the primary sealing body 21B along the primary sealing body 21B, and the reinforcing member 26 is joined to the lower surface of the primary sealing body 21C along the primary sealing body 21C. To. The reinforcing members 25 and 26 are joined to the primary sealing bodies 21B and 21C, respectively, by, for example, welding.

Subsequently, a laminating step S4 for forming the electrode laminated body 11 by laminating the negative electrode terminal electrode 18, the plurality of bipolar electrodes 14, and the positive electrode terminal electrode 19 in this order along the stacking direction D via the separator 13 is performed. It is said. In the laminating step S4, the outer edge portion 13a of the separator 13 is arranged in the extending region 23c of the resin layer 23, and the peripheral edge portion of the other electrode plate 15 is placed on the resin layer 24 formed on one electrode plate 15. The negative electrode termination electrode 18, the plurality of bipolar electrodes 14, and the positive electrode termination electrode 19 are stacked in this order so that the 15c is stacked.

Subsequently, the secondary molding step S5 for forming the secondary sealing body 22 around the plurality of primary sealing bodies 21 provided on the electrode laminated body 11 is performed. As shown in FIG. 5, in the secondary molding step S5, the secondary sealing body 22 is formed by injection molding using the molding die 40. Here, the configuration of the molding die 40 will be described. The molding die 40 includes a lower die 41 and an upper die 42.

The lower mold 41 has a bottom wall 43, a side wall 44, and a pressing portion 45. The bottom wall 43 is a rectangular metal plate having an area one size larger than the area of the electrode laminate 11 viewed from the stacking direction D. The side wall 44 is a rectangular tubular metal member erected on the peripheral edge of the bottom wall 43. The side wall 44 extends upward from the upper surface of the bottom wall 43. The pressing portion 45 is a portion for restraining the electrode laminated body 11 along the laminating direction D. The pressing portion 45 is provided on the bottom wall 43 and projects upward from the upper surface of the bottom wall 43.

The upper die 42 has an upper wall 46, a side wall 47, and a pressing portion 48 projecting downward from the upper wall 46. The upper wall 46 is a rectangular metal plate having an area one size larger than the area of the electrode laminate 11 viewed from the stacking direction D. The upper wall 46 has the same shape as the bottom wall 43. The side wall 47 is a rectangular tubular metal member erected on the peripheral edge of the upper wall 46. The side wall 47 extends downward from the lower surface of the upper wall 46. The pressing portion 48 is a portion for restraining the electrode laminated body 11 along the laminating direction D. The pressing portion 48 is provided on the upper wall 46 and projects downward from the lower surface of the upper wall 46.

In the secondary molding step S5, the electrode laminate 11 is placed on the lower mold 41 so that the peripheral edge portion of the electrode laminate 11 overlaps the pressing portion 45 of the lower mold 41 in the lamination direction D. Then, the upper die 42 is joined to the lower die 41 by mold clamping so that the side wall 44 and the side wall 47 are connected to each other. As a result, the cavity C is formed around the plurality of primary sealing bodies 21 provided on the electrode laminated body 11. At this time, the electrode laminate 11 is constrained in the stacking direction D while the peripheral edge portion of the electrode laminate 11 and the inner edge portions 21a of the plurality of primary sealing bodies 21 are pressed by the pressing portion 45 and the pressing portion 48. .. Further, the inner edge 25b of the reinforcing member 25 contacts the side surface 48a of the pressing portion 48, and the inner edge 26b of the reinforcing member 26 contacts the side surface 45a of the pressing portion 45.

That is, the pressing portion 48 and the reinforcing member 25 are arranged so as to face each other in the direction (second direction) where the pressing portion 48 and the reinforcing member 25 intersect (orthogonally) the stacking direction D, and the pressing portion 45 and the reinforcing member 26 intersect (orthogonally) the stacking direction D. The electrode laminate 11 is constrained along the stacking direction D by the molding die 40 so as to be arranged so as to face each other in the direction in which the electrodes are laminated. Then, when the resin material is poured (injected) into the cavity C, injection molding is performed to form the secondary sealing body 22. From the above, the power storage module 4 is obtained.

In the method of manufacturing the power storage module 4 and the power storage module 4 described above, a plurality of primary sealants 21 are formed on the peripheral edges 15c of the electrode plates 15 of the negative electrode terminal 18, the plurality of bipolar electrodes 14, and the positive electrode terminal 19. The secondary encapsulant 22 is formed around the plurality of primary encapsulants 21 by injection molding using the molding die 40. The secondary sealing body 22 is formed by injecting a resin material into the cavity C formed by the molding die 40 in a state where the electrode laminated body 11 is restrained along the stacking direction D by the molding die 40. To. At this time, molding pressure is applied to the side surface 11a of the electrode laminate 11.

By the way, the thickness of the electrode laminate 11 (the length in the lamination direction D) may vary due to the manufacturing tolerance of the bipolar electrode 14 and the like. When the electrode laminate 11 is thick, a sufficient restraining load is applied to the electrode laminate 11 by the lower mold 41 and the upper mold 42, so that the electrode laminate 11 is almost deformed even when molding pressure is applied. There is no. On the other hand, when the electrode laminate 11 is thin, the restraining load applied to the electrode laminate 11 by the lower mold 41 and the upper mold 42 becomes smaller. In this case, if molding pressure is applied to the side surface 11a of the electrode laminate 11, the electrode laminate 11 may be deformed.

In the power storage module 4, a reinforcing member 25 is provided on the primary sealing body 21B located at one end 11b of the electrode laminated body 11, and the reinforcing member 25 is an upper mold in a direction intersecting (orthogonal) with the stacking direction D. It is arranged so as to face the pressing portion 48 of the 42. Therefore, when the reinforcing member 25 interferes with the pressing portion 48 of the upper mold 42, it is possible to prevent the primary sealing body 21B from being rolled up by the forming pressure. Similarly, the primary sealing body 21C located at the other end 11c of the electrode laminated body 11 is provided with a reinforcing member 26, and the reinforcing member 26 is provided with a lower mold 41 in a direction intersecting (orthogonal) with the stacking direction D. It is arranged so as to face the pressing portion 45 of the above. Therefore, when the reinforcing member 26 interferes with the pressing portion 45 of the lower mold 41, it is possible to prevent the primary sealing body 21C from being rolled up by the forming pressure. As a result, it is possible to suppress the deformation of the electrode laminate 11 during injection molding. As a result, the allowable range of the tolerance of the thickness of the electrode laminate 11 (the length in the lamination direction D) is widened. Therefore, it is possible to improve the yield of the power storage module 4.

The reinforcing members 25 and 26 are made of metal. Therefore, since the reinforcing members 25 and 26 have high rigidity, deformation of the reinforcing members 25 and 26 due to molding pressure is suppressed. As a result, it is possible to further suppress the primary sealing bodies 21B and 21C from being rolled up by the molding pressure, and it is possible to further suppress the deformation of the electrode laminate 11 during injection molding.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments.

For example, in the above embodiment, the reinforcing members 25 and 26 are made of metal, but the present invention is not limited to this. The reinforcing members 25 and 26 may be made of resin. Further, in the above embodiment, the reinforcing member 25 and the primary sealing body 21B are separate bodies (separate members), but the reinforcing member 25 and the primary sealing body 21B may be integrated (same member). In this case, since the joint strength between the reinforcing member 25 and the primary sealing body 21B is high, deformation of the reinforcing member 25 due to molding pressure is suppressed. As a result, it is possible to further suppress the primary sealing body 21B from being rolled up by the molding pressure, and it is possible to further suppress the deformation of the electrode laminate 11 during injection molding.

Similarly, in the above embodiment, the reinforcing member 26 and the primary sealing body 21C are separate bodies (separate members), but the reinforcing member 26 and the primary sealing body 21C may be integrated (same member). .. In this case, since the joint strength between the reinforcing member 26 and the primary sealing body 21C is high, deformation of the reinforcing member 26 due to molding pressure is suppressed. As a result, it is possible to further suppress the primary sealing body 21C from being rolled up by the molding pressure, and it is possible to further suppress the deformation of the electrode laminate 11 during injection molding.

The sealing body 12 may have at least one of the reinforcing member 25 and the reinforcing member 26. Even in this case, it is possible to suppress the curling up of the primary sealing body 21 at both ends of the electrode laminated body 11 in the stacking direction D where the reinforcing member is provided, and the electrode laminated body 11 at the time of injection molding. It is possible to suppress the deformation of.

In the above embodiment, the inner edge 25b of the reinforcing member 25 is in contact with the side surface 48a of the pressing portion 48, but may be separated from each other. That is, the reinforcing member 25 may be arranged so as to face the pressing portion 48 in a direction intersecting (orthogonal) with the stacking direction D. Even in this case, since the reinforcing member 25 that has received the molding pressure can interfere with the pressing portion 48, it is possible to prevent the primary sealing body 21B from being rolled up by the molding pressure. As a result, it is possible to suppress the deformation of the electrode laminate 11 during injection molding.

Similarly, the inner edge 26b of the reinforcing member 26 is in contact with the side surface 45a of the pressing portion 45, but may be separated from each other. That is, the reinforcing member 26 may be arranged so as to face the pressing portion 45 in a direction intersecting (orthogonal) with the stacking direction D. Even in this case, since the reinforcing member 26 that has received the molding pressure can interfere with the pressing portion 45, it is possible to prevent the primary sealing body 21C from being rolled up by the molding pressure. As a result, it is possible to suppress the deformation of the electrode laminate 11 during injection molding.

In the above embodiment, the reinforcing step S3 is performed after the primary molding step S2, but may be performed before the primary molding step S2. That is, the reinforcing members 25 and 26 may be formed after the primary forming step S2, or may be formed before the primary forming step S2.

Further, the reinforcing step S3 may be performed at the same time as the primary molding step S2. That is, the reinforcing member 25 may be formed when the primary sealing body 21B is welded to the electrode plate 15 of the negative electrode terminal electrode 18 by hot pressing in the primary molding step S2. The reinforcing member 26 may be formed when the primary sealant 21C is welded to the electrode plate 15 of the positive electrode terminal electrode 19 by hot pressing in the primary molding step S2. Specifically, by pressing the primary encapsulant body 21B and the peripheral edge portion 15c against the heater with a stepped block, the reinforcing member 25 is formed and the primary encapsulant body 21B is attached to the peripheral edge portion 15c of the negative electrode terminal electrode 18. It is welded. Similarly, by pressing the primary sealing body 21C and the peripheral edge portion 15c against the heater with the stepped block, the reinforcing member 26 is formed and the primary sealing body 21C is welded to the peripheral edge portion 15c of the positive electrode terminal electrode 19. To. In this case, since the formation (welding) of the primary sealing bodies 21B and 21C and the formation of the reinforcing members 25 and 26 are performed in the same process, the man-hours can be reduced.

4 ... power storage module, 11 ... electrode laminate, 11b ... one end, 11c ... other end, 14 ... bipolar electrode (electrode), 15 ... electrode plate, 15c ... peripheral edge, 18 ... negative electrode terminal electrode (electrode), 19 ... positive electrode Termination electrode (electrode), 21 ... primary sealant, 21B ... primary sealant, 21C ... primary sealant (another primary sealant), 22 ... secondary sealant, 25 ... reinforcing member (first) Reinforcing member), 26 ... Reinforcing member (second reinforcing member), 40 ... Molding mold, 41 ... Lower mold, 42 ... Upper mold, 45 ... Pressing part, 48 ... Pressing part, C ... Cavity, D ... Stacking direction (No. 1) One direction).

Claims (4)

An electrode laminate containing a plurality of electrodes laminated along the first direction, and
A plurality of primary sealants provided on the peripheral edges of the electrode plates of the plurality of electrodes, and
The secondary seals provided around the plurality of primary seals and
A first reinforcing member provided on the primary sealing body located at one end in the first direction of the electrode laminated body among the plurality of primary sealing bodies, and a first reinforcing member.
A second reinforcing member provided in another primary sealing body located at the other end in the first direction of the electrode laminate among the plurality of primary sealing bodies, and
With
The first reinforcing member is sandwiched between the primary sealing body and the secondary sealing body in the first direction, and is made of metal.
The second reinforcing member is sandwiched between the other primary sealing body and the secondary sealing body in the first direction.
The inner edge of the first reinforcing member is located outside the inner edge of the primary sealing body and coincides with the inner edge of one end of the secondary sealing body located at one end in the first direction. And
The inner edge of the second reinforcing member is located outside the inner edge of the other primary sealing body, and is located at the other end of the secondary sealing body in the first direction. A power storage module that matches the inner edge . An electrode laminate containing a plurality of electrodes laminated along the first direction, and
A plurality of primary sealants provided on the peripheral edges of the electrode plates of the plurality of electrodes, and
The secondary seals provided around the plurality of primary seals and
A first reinforcing member provided on the primary sealing body located at one end in the first direction of the electrode laminated body among the plurality of primary sealing bodies, and a first reinforcing member.
A second reinforcing member provided in another primary sealing body located at the other end in the first direction of the electrode laminate among the plurality of primary sealing bodies, and
With
The first reinforcing member is sandwiched between the primary sealing body and the secondary sealing body in the first direction, and is integrated with the primary sealing body.
The second reinforcing member is sandwiched between the other primary sealing body and the secondary sealing body in the first direction.
The inner edge of the first reinforcing member is located outside the inner edge of the primary sealing body and coincides with the inner edge of one end of the secondary sealing body located at one end in the first direction. And
The inner edge of the second reinforcing member is located outside the inner edge of the other primary sealing body, and is located at the other end of the secondary sealing body in the first direction. A power storage module that matches the inner edge . The process of preparing a plurality of electrodes each having an electrode plate, and
A step of forming a plurality of primary sealants on the peripheral edge of the electrode plate of each of the plurality of electrodes, and
A step of forming an electrode laminate by laminating the plurality of electrodes along the first direction, and
A step of forming a secondary encapsulant by injection molding using a molding die around the plurality of primary encapsulants provided on the electrode laminate.
With
The molding mold includes a pair of pressing portions for restraining the electrode laminate along the first direction.
A first reinforcing member is provided on the primary sealing body located at one end of the electrode laminated body in the first direction among the plurality of primary sealing bodies.
A second reinforcing member is provided in another primary sealing body located at the other end of the electrode laminate in the first direction among the plurality of primary sealing bodies.
In the step of forming the secondary sealing body, the inner edge of the first reinforcing member comes into contact with the side surface of one of the pair of pressing portions in the second direction intersecting with the first direction, and the above-mentioned The molding die causes the electrode laminate to follow the first direction so that the inner edge of the second reinforcing member contacts the side surface of the other pressing portion of the pair of pressing portions in the second direction. A method for manufacturing a power storage module, in which the secondary encapsulant is formed by injecting a resin material into a cavity formed by the molding die while being restrained. The production of the power storage module according to claim 3 , wherein the reinforcing member is formed by welding the primary sealing body to the electrode plate by a hot press in a step of forming the plurality of primary sealing bodies. Method.

Images