JP2019117757A - Power-storage module - Google Patents

Abstract

To provide a power-storage module which enables the achievement of the build reduction.SOLUTION: A power-storage module according to an embodiment hereof comprises: a laminate in which bipolar electrodes each including an electrode plate, a positive electrode provided on one face of the electrode plate and a negative electrode provided on the other face of the electrode plate are laminated through a separator. As to each of the electrode plates disposed at opposing ends of the laminate, the positive or negative electrode is provided only one face thereof. The power-storage module is provided with frame-like first resin parts formed on edge portions of the electrode plates disposed at the opposing ends of the laminate; and a plurality of frame-like second resin parts each formed on the edge portion of the one face of the electrode plate of the corresponding bipolar electrode in a lamination direction of the laminate. The second resin parts are disposed on an inner side with respect to the first resin parts in the lamination direction of the laminate, and the first resin parts are thinner than the second resin parts.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a storage module.

  As a conventional storage module, there is known a so-called bipolar storage module including a bipolar electrode in which a positive electrode is formed on one surface of an electrode plate and a negative electrode is formed on the other surface (see Patent Document 1). Such a storage module includes a stacked body formed by stacking a plurality of bipolar electrodes. On the side surface of the laminate, a resin group is provided which seals between the bipolar electrodes adjacent in the stacking direction. An electrolytic solution is accommodated in an internal space formed between adjacent bipolar electrodes.

JP 2005-5163 A

  By the way, in the storage module described in Patent Document 1, in order to prevent leakage of the electrolytic solution, the internal space formed between adjacent bipolar electrodes is sealed with a resin member to ensure liquid tightness. . On the other hand, in order to improve the mountability to various vehicles such as a forklift, a hybrid car, and an electric car, it is necessary to reduce the physique of members which do not directly contribute to the power generation.

The object of the present invention is made in view of the above-mentioned circumstances, and an object thereof is to provide an electricity storage module which realizes reduction in physical size.

  An electricity storage module for achieving the above object has a laminate including an electrode plate, a positive electrode provided on one surface of the electrode plate, and a bipolar electrode including a negative electrode provided on the other surface of the electrode plate via a separator. The electrode plates disposed at both ends in the stacking direction of the laminate have the positive electrode or the negative electrode provided on only one side. An electrode plate provided with only a positive electrode on one side is referred to as a positive electrode side terminal electrode, and an electrode plate provided with only a negative electrode on the other side is referred to as a negative electrode side terminal electrode. A frame-shaped first resin portion formed on the edge of the electrode plate of the positive electrode side terminal electrode at one end of the both ends in the lamination direction of the laminate and at the other end of the two ends, and lamination of the laminate And a plurality of frame-like second resin portions formed on the edge of one surface of the electrode plate of each bipolar electrode in the direction, and the second resin portion is the first resin in the lamination direction of the laminate. The first resin portion is disposed inside the portion, and the first resin portion is thinner than the second resin portion.

  According to this configuration, by reducing the thickness of the first resin portion in the stacking direction of the stacked body, a physique reduction effect is possible.

  According to the present invention, it is possible to provide a storage module having a physique reduction effect.

It is a schematic sectional drawing which shows one Embodiment of an electrical storage apparatus provided with an electrical storage module. It is a schematic sectional drawing which shows one Embodiment of the electrical storage module shown by FIG. It is a principal part expanded sectional view of an electrical storage module shown by FIG.

  Hereinafter, an embodiment of the present invention will be described according to FIGS. 1 to 3.

  Power storage device 10 shown in FIG. 1 is used, for example, as a battery of various vehicles such as a forklift, a hybrid car, and an electric car. The storage device 10 includes a plurality of (three in the present embodiment) storage modules 12, but may include a single storage module 12. The storage module 12 is, for example, a bipolar battery. The storage module 12 is, for example, a secondary battery such as a nickel hydrogen secondary battery or a lithium ion secondary battery, but may be an electric double layer capacitor. The following description exemplifies a nickel-hydrogen secondary battery.

  The plurality of storage modules 12 may be stacked via a conductive plate 14 such as a metal plate, for example. As viewed in the stacking direction D1 (the Z direction in FIG. 1), the storage module 12 and the conductive plate 14 have, for example, a rectangular shape. Details of each storage module 12 will be described later. The storage modules 12 are stacked via the conductive plate 14. The conductive plates 14 are disposed at both ends of the storage module 12 in the stacking direction D1 and are electrically connected to the adjacent storage modules 12. Thereby, the plurality of power storage modules 12 are connected in series in the stacking direction D1. The positive electrode terminal 24 is connected to the conductive plate 14 positioned at one end in the stacking direction D1, and the negative electrode terminal 26 is connected to the conductive plate 14 positioned at the other end. The positive electrode terminal 24 may be integral with the conductive plate 14 to be connected. The negative electrode terminal 26 may be integral with the conductive plate 14 to be connected. The positive electrode terminal 24 and the negative electrode terminal 26 extend in the direction orthogonal to the stacking direction D1. The charge and discharge of the power storage device 10 can be performed by the positive electrode terminal 24 and the negative electrode terminal 26.

  Conductive plate 14 can also function as a heat sink for releasing the heat generated in storage module 12. By passing a refrigerant such as air through the plurality of air gaps 14 a provided inside the conductive plate 14, the heat from the storage module 12 can be efficiently released to the outside. Each void 14a extends, for example, in a direction (Y direction in FIG. 1) orthogonal to the stacking direction D1. The conductive plate 14 is smaller than the storage module 12 when viewed from the stacking direction D1, but may be the same as or larger than the storage module 12.

  The storage device 10 may include a restraint member 16 for restraining the storage modules 12 and the conductive plates 14 stacked alternately in the stacking direction D1. The constraining member 16 includes a pair of constraining plates 16A and 16B and a connecting member (bolt 18 and nut 20) that interconnects the constraining plates 16A and 16B. An insulating film 22 such as a resin film, for example, is disposed between the restraint plates 16A and 16B and the conductive plate 14. Each restraint plate 16A, 16B is made of, for example, a metal such as iron. When viewed from the stacking direction D1, each of the restraint plates 16A, 16B and the insulating film 22 has, for example, a rectangular shape. The insulating film 22 is larger than the conductive plate 14, and the restraint plates 16 </ b> A and 16 </ b> B are larger than the storage module 12. As seen from the stacking direction D1, at the edge of the restraint plate 16A, an insertion hole H1 through which the shaft of the bolt 18 is inserted is provided at a position outside the storage module 12. Similarly, as viewed from the stacking direction D1, an insertion hole H2 through which the shaft portion of the bolt 18 is inserted is provided at a position outside the storage module 12 at the edge of the restraint plate 16B. When each restraint plate 16A, 16B has a rectangular shape when viewed from the stacking direction D1, the insertion hole H1 and the insertion hole H2 are located at the corners of the restraint plates 16A, 16B.

  One restraint plate 16A is abutted against the conductive plate 14 connected to the negative electrode terminal 26 via the insulating film 22, and the other restraint plate 16B is attached to the conductive plate 14 connected to the positive electrode terminal 24. It is hit through. The bolt 18 is, for example, passed through the insertion hole H1 from one restraint plate 16A side to the other restraint plate 16B side, and a nut 20 is screwed into the tip of the bolt 18 projecting from the other restraint plate 16B. There is. As a result, the insulating film 22, the conductive plate 14 and the storage module 12 are sandwiched to form a unit, and a restraint load is applied in the stacking direction D1.

FIG. 3 is an enlarged sectional view of an essential part of the storage module. Specifically, FIG. 3 shows one side in the X direction (the left side in FIG. 2) of the outer edge (each of the upper edge and the lower edge) in the stacking direction D1 of the laminate constituting the storage module It is the figure which expanded and showed the part of. In addition, in FIG. 2 which shows schematic structure of an electrical storage module, illustration of the detailed structure (The structure of the outer edge part E shown in FIG. 3) of the outer edge part of a laminated body is abbreviate | omitted.

  A stacked body 30 in which a plurality of bipolar electrodes (electrodes) 32 are stacked is shown in FIGS. 2 and 3. The laminate 30 has, for example, a rectangular shape as viewed in the stacking direction D1 of the bipolar electrode 32. A separator 40 may be disposed between adjacent bipolar electrodes 32. The bipolar electrode 32 includes an electrode plate 34, a positive electrode 36 provided on one surface of the electrode plate 34, and a negative electrode 38 provided on the other surface of the electrode plate 34. In the laminate 30, the positive electrode 36 of one bipolar electrode 32 faces the negative electrode 38 of one bipolar electrode 32 adjacent in the stacking direction D1 with the separator 40 interposed therebetween, and the negative electrode 38 of one bipolar electrode 32 is a separator 40. And the positive electrode 36 of the other bipolar electrode 32 adjacent in the stacking direction D1. In the stacking direction D1, an electrode plate 34 (a negative electrode side termination electrode) having the negative electrode 38 disposed on the inner surface is disposed at one end of the laminate 30 and a positive electrode 36 is disposed on the inner surface at the other end of the laminate 30. The arranged electrode plate 34 (positive electrode side end electrode) is arranged. The negative electrode 38 of the negative electrode side termination electrode faces the positive electrode 36 of the uppermost bipolar electrode 32 via the separator 40. The positive electrode 36 of the positive electrode side termination electrode faces the negative electrode 38 of the lowermost bipolar electrode 32 via the separator 40. The electrode plates 34 of these terminal electrodes are connected to the adjacent conductive plates 14 (see FIG. 1).

  The storage module 12 includes a frame 50 that holds the edge 34 a of the electrode plate 34 on the side surface 30 a of the stack 30 extending in the stacking direction D 1. The frame 50 is provided around the laminated body 30 as viewed in the laminating direction D1. Specifically, the frame 50 is configured to surround the side surface 30 a of the stacked body 30. The frame 50 is provided at the edge 34a of the electrode plate 34 located at the outermost layer when viewed from the stacking direction D1, and extends from the center of the electrode plate 34 outward in the direction perpendicular to the stacking direction D1. A plurality of second resin portions 54 provided at the edge 34 a of each electrode plate 34 and having a plurality of second resin portions 54 each having an overhang portion 54 b protruding from the end 34 b of the electrode plate 34; And a third resin portion 56 provided around the plurality of first resin portions 52 and the second resin portion 54 when viewed from D1.

  The inner wall of the frame 50 is composed of a first resin portion 52 and a second resin portion 54. The second resin portion 54 constituting the inner wall of the frame 50 extends from the edge 34 a of one surface of the electrode plate 34 of each bipolar electrode 32 (here, the surface on which the positive electrode 36 is formed) to the end 34 b of the electrode plate 34. It is provided. When viewed in the stacking direction D 1, the second resin portions 54 are provided all around the edge 34 a of the electrode plate 34 of each bipolar electrode 32. Adjacent second resin portions 54 abut each other on a surface extending outside the other surface of the electrode plate 34 of each bipolar electrode 32 (here, the surface on which the negative electrode 38 is formed). As a result, the second resin portion 54 and the edge 34 a of the electrode plate 34 of each bipolar electrode 32 are held by heat welding and joining. In the present embodiment, the thickness of the second resin portion 54 in the stacking direction D1 is 100 to 400 μm.

  The first resin portion 52 constituting the inner wall of the frame 50 is provided at the edge 34 a of one surface of the electrode plate 34 located at both ends of the laminate 30. Similar to the edge 34 a of the electrode plate 34 of each bipolar electrode 32 being held by the second resin portion 54, the edge 34 a of the electrode plate 34 disposed at both ends of the laminate 30 is combined with the first resin portion 52. It is held in the second resin portion 54 in a buried state. Specifically, for the positive electrode side terminal electrode, the first resin portion 52 is provided on the outer surface (the surface connected to the conductive plate 14) of the positive electrode side terminal electrode. That is, the edge portion 34a of the positive electrode side termination electrode is formed of the first resin portion 52 (the first resin portion 52 provided at the bottom of FIG. 2) provided on the outer surface of the positive electrode side termination electrode; It is held in a state of being buried in a second resin portion 54 provided on the other surface of the electrode. The first resin portion 52 is provided on the outer surface (the surface connected to the conductive plate 14) of the negative electrode-side terminal electrode for the negative electrode-side terminal electrode. That is, the edge portion 34a of the negative electrode side terminal electrode is formed of the first resin portion 52 (the first resin portion 52 provided at the top in FIG. 2) provided on the outer surface of the negative electrode side terminal electrode It is held in a state of being buried in a second resin portion 54 provided on one surface of the bipolar electrode 32 adjacent to the electrode. In the stacking direction D1, the thickness of the first resin portion 52 is thinner than that of the second resin portion 54, and is 20 to 100 μm in the present embodiment. Further, the thickness of the first resin frame 52 provided on the negative electrode side terminal electrode is provided to be thicker than the thickness of the electrode plate 34. An internal space V partitioned in a liquid-tight manner by the electrode plates 34 and 34 and the first resin portion 52 is formed between the electrode plates 34 and 34 adjacent to each other in the stacking direction D1. In the internal space V, an electrolytic solution (not shown) made of an alkaline solution such as a potassium hydroxide aqueous solution is accommodated.

  The third resin portion 56 constituting the outer wall of the frame 50 is a frame-shaped portion extending with the stacking direction D1 as an axial direction. The third resin portion 56 extends over the entire length of the stacked body 30 in the stacking direction D1. The third resin portion 56 covers the outer side surfaces of the first resin portion 52 and the second resin portion 54 extending in the stacking direction D1. The third resin portion 56 is formed by injection molding described later. The third resin portion 56 has an annular flange portion 56a extending inward at each of both end portions in the stacking direction D1. The flange portion 56 a is a portion covering at least a part of the outer side surface in the stacking direction D 1 of the first resin portion 52 located at the stacking end of the stacked body 30. The stacked body 30 is sandwiched by flange portions 56 a formed at both end portions in the stacking direction D1. In the present embodiment, the thickness of the flange portion 56a in the stacking direction D1 is 0.6 to 1 mm. Further, the thickness width of the third resin portion, that is, the thickness from the outer wall of the frame 50 to the end (the end 52a and the end 54a) of the inner wall of the frame 50 is 4 to 6 mm.

  The electrode plate 34 is a rectangular metal foil made of, for example, nickel. Alternatively, the electrode plate 34 may be a nickel plated steel plate. The edge portion 34 a of the electrode plate 34 is an uncoated region on which the positive electrode active material and the negative electrode active material are not coated, and the first resin portion 52 and the first resin portion constituting the inner wall of the frame 50 2) It is an area which is buried and held in the resin part 54. As a positive electrode active material which comprises the positive electrode 36, nickel hydroxide is mentioned, for example. As a negative electrode active material which comprises the negative electrode 38, a hydrogen storage alloy is mentioned, for example. The formation region of the negative electrode 38 on the other surface of the electrode plate 34 is one size larger than the formation region of the positive electrode 36 on one surface of the electrode plate 34.

  The separator 40 is formed, for example, in a sheet shape. Examples of the material for forming the separator 40 include porous films made of polyolefin resins such as polyethylene (PE) and polypropylene (PP), and woven or non-woven fabrics made of polypropylene and the like. The separator 40 may be reinforced with a vinylidene fluoride resin compound or the like. The separator 40 is not limited to a sheet but may be a bag.

  Examples of the resin material constituting the frame 50 include polypropylene (PP), polyethylene (PE), polyphenylene sulfide (PPS), and modified polyphenylene ether (modified PPE).

Next, the operation of the present embodiment will be described.
According to the above embodiment, the following effects can be obtained.
(1) The storage module according to the present invention reduces the physical size of members that do not directly contribute to power generation and reduces the physical size of the entire storage module, so that it can be mounted on various vehicles such as forklifts, hybrid vehicles and electric vehicles Improve. In particular, when arranged under the rear seat, it produces a great effect.
(2) When the resin part and the electrode plate are heat-welded, the contraction amount of the resin part becomes larger than the contraction amount of the electrode plate due to the temperature difference between the resin portion and the metal electrode plate. It is known to happen. However, by reducing the thickness of the first resin portion 52, the amount of warpage of the electrode plate 34 is reduced. The thickness of the third resin portion 56 can also be reduced, and the amount of warpage of the laminate 30 is also reduced. As a result of the reduction of the amount of warpage of the stacked body 30, the assemblability and ease of stacking of the storage module are improved.
The above embodiment may be modified as follows.
In the present embodiment, the adjacent second resin portions 54 abut each other on the surface extending outside the surface on which the negative electrode 38 of each bipolar electrode 32 is formed, but on the surface on which the positive electrode 36 is formed You may make it contact | abut in the surface extended outward. In this case, the edge 34a of the negative electrode side terminal electrode is buried in the first resin portion 52 provided on the outer surface of the negative electrode side terminal electrode and the second resin portion 54 provided on the other surface of the negative electrode side terminal electrode. It is held in the closed state. The edge 34a of the positive electrode side termination electrode is a first resin portion 52 provided on the outer surface of the positive electrode side termination electrode and a second resin provided on one surface of the bipolar electrode 32 adjacent to the positive electrode side termination electrode. It is held in a state of being buried in the part 54.

DESCRIPTION OF SYMBOLS 10 electricity storage device 12 electricity storage module 14 conductive plate 16 restraint member 16A restraint plate 16B restraint plate 18 volt 20 nut 22 insulation film 24 positive electrode terminal 26 negative electrode terminal 30 laminated body 32 bipolar electrode 34 electrode plate 34a edge 34b end 36 positive electrode 38 negative electrode 40 separator 50 frame 52 first resin portion 52a end portion 52b overhang portion 54 second resin portion 54a end portion 54b overhang portion 56 third resin portion 56a flange portion D1 stacking direction H1 insertion hole H2 insertion hole

Claims (5)

An electrode plate, a positive electrode provided on one surface of the electrode plate, and a laminated body in which a plurality of bipolar electrodes including a negative electrode provided on the other surface of the electrode plate are laminated via a separator.
A positive electrode side end electrode provided at one end of the both ends in the laminating direction of the laminate, provided with only the positive electrode on one surface of the electrode plate;
A negative electrode side terminal electrode provided on the other surface of the electrode plate and provided only with the negative electrode, disposed at the other end of both ends in the laminating direction of the laminated body;
A storage module having
A frame-shaped first resin portion formed at an edge portion of the electrode plate of the negative electrode side terminal electrode and the positive electrode side terminal electrode disposed at both ends in the laminating direction of the laminate;
A plurality of frame-like second resin portions formed on an edge of one surface of the electrode plate of each of the bipolar electrodes in the stacking direction of the stack;
Have
In the storage direction of the stack, the second resin portion is disposed inside the first resin portion, and the first resin portion is thinner than the second resin portion.
The edge portion of the electrode plate of the positive electrode side termination electrode disposed at one end of the both ends of the laminate and the negative electrode side termination electrode disposed at the other end of the two ends is the first resin portion and the second resin portion. It is hold | maintained in the state joined to the resin part. The electrical storage module of Claim 1 characterized by the above-mentioned.
The second resin portions adjacent to each other are in contact with each other in a surface extending outward in the surface direction of the surface on which the negative electrode of the electrode plate of each bipolar electrode is formed. The storage module according to claim 2.
The edge portion of the negative electrode side terminal electrode is formed on the first resin portion provided on the outer side surface of the negative electrode side terminal electrode, and the second resin member provided on one side of the bipolar electrode adjacent to the negative electrode side terminal electrode. The power storage module according to any one of claims 1 to 3, which is held in a state of being bonded to a resin portion.
The edge portion of the positive electrode side terminal electrode is joined to the first resin portion provided on the outer surface of the positive electrode side terminal electrode and the second resin portion provided on the other surface of the positive electrode side terminal electrode The power storage module according to any one of claims 1 to 4, which is held in a state.

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