JP6874482B2 - Power storage module and its manufacturing method - Google Patents

Description

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

Patent Document 1 includes a power generation element in which a positive electrode and a negative electrode are laminated via an electrolyte layer containing a separator in an internal space formed by a seal portion, and a current collector connected to each of the positive electrode and the negative electrode. At the same time, a battery including a tube connecting the internal space and the external space of the seal portion is disclosed. The tube is used for injecting the electrolytic solution into the internal space, and also functions as a degassing safety valve when the internal pressure rises.

Japanese Unexamined Patent Publication No. 2004-178909

In the configuration according to the prior art described above, since the tube is provided in the seal portion, the tube is caused by displacement, deformation, breakage, etc. of the sea tube, or due to a relative positional deviation of the component of the seal portion that holds the tube. It is possible that the function of the device will be impaired.

After diligent research, the inventors have newly found a seal portion configuration that can function as an electrolytic solution inlet and a gas vent safety valve, and that can more reliably maintain the function.

An object of the present invention is to provide a power storage module provided with a seal portion having a novel configuration and a method for manufacturing the same.

In the power storage module according to one aspect of the present invention, a plurality of bipolar electrodes including an electrode plate, a positive electrode provided on one surface of the electrode plate, and a negative electrode provided on the other surface of the electrode plate are interposed via a separator. The laminated body and the frame body joined to the peripheral edge of each electrode plate of the plurality of bipolar electrodes extend in the stacking direction of the laminated body so as to accommodate the laminated body in the stacking direction of the laminated body. A power storage module including a sealing member having a tubular sealing portion formed by being overlapped, and the sealing end surface of the sealing portion composed of peripheral end faces of adjacent frames in the stacking direction of the laminated body is a heat welding surface. Therefore, the seal end surface of the seal portion is provided with a communication port that penetrates the seal portion in a direction orthogonal to the stacking direction between adjacent frames in the stacking direction.

The power storage module includes a seal portion having a new configuration in which the seal end face is a heat welding surface and the seal end face is provided with a communication port. Since the end face of the seal is heat-welded, the relative positional deviation of the plurality of frames constituting the seal portion is suppressed. Therefore, for example, when the communication port is used as an electrolytic solution injection port or a degassing safety valve, those are used. The situation where the function is damaged is effectively suppressed.

The communication port is a liquid injection port (that is, an electrolytic solution injection port) for injecting an electrolytic solution into the seal portion, and a pressure adjusting valve (that is, a degassing safety valve) that opens and closes according to the internal pressure in the seal portion. It can be used as both or either.

In the method for manufacturing a power storage module according to one aspect of the present invention, a plurality of bipolar electrodes including an electrode plate, a positive electrode provided on one surface of the electrode plate, and a negative electrode provided on the other surface of the electrode plate are provided. The laminated body laminated via the separator and the frame body extending in the stacking direction of the laminated body so as to accommodate the laminated body and being joined to the peripheral edge of each electrode plate of the plurality of bipolar electrodes are formed of the laminated body. A method for manufacturing a power storage module including a sealing member having a tubular sealing portion configured by being stacked in a stacking direction, wherein a plurality of frames are joined to the peripheral edge of each electrode plate of a plurality of bipolar electrodes. A laminating step of laminating the bipolar electrode unit via a separator, a heat welding step of heat-welding the seal end faces composed of peripheral end faces of adjacent frames in the laminating direction of the laminated body, and a heat-welded seal end face. The step includes a communication port forming step of providing a communication port penetrating the seal portion in a direction orthogonal to the stacking direction between adjacent frames in the stacking direction.

In the method for manufacturing the power storage module, the seal end face is heat-welded in the heat welding step, and the seal end face is provided with the communication port in the communication port forming step, so that the power storage module provided with the seal portion having a new configuration can be obtained. can get. By heat-welding the end face of the seal, the relative positional deviation of the plurality of frames constituting the seal portion is suppressed. Therefore, for example, when the communication port is used as an electrolytic solution injection port or a degassing safety valve, those functions are functioning. The situation of being damaged is effectively suppressed.

In the method for manufacturing a power storage module according to another form, in the laminating step, a plurality of bipolar electrode units are laminated by interposing a nest extending from the inside of the frame to the outside of the frame between adjacent frames in the laminating direction. Then, in the heat welding step, the seal end face of the seal portion is heat welded with the nesting interposed therebetween, and in the communication port forming step, the nesting is removed from the seal portion in which the seal end face is heat welded. In this case, nesting is used when the communication port is provided. At this time, since the size of the communication port provided is the same as the outer diameter of the nest, the size of the communication port can be easily adjusted by adjusting the outer diameter of the nest.

In the method for manufacturing a power storage module according to another form, in the laminating step, a plurality of bipolar electrode units are laminated by interposing a plurality of nests between different frames of the plurality of bipolar electrode units, and a plurality of nested frames are laminated. The outer edges are not overlapped in the stacking direction of the laminate. In this case, the work of removing the plurality of nests in the communication port forming step becomes easy. For example, the gripper of the automatic machine can grip the outer end of the nesting frame, and a plurality of nesting can be sequentially removed, so that automation in the manufacture of the power storage module is promoted.

In the method for manufacturing a power storage module according to another form, in the laminating step, a plurality of nests are projected out of the frame from the same frame position in the laminating direction of the laminated body, and the protruding length protruding from the frame in the out-of-frame direction is large. Intervene differently. Alternatively, in the laminating step, a plurality of nests are interposed so as to project out of the frame from different frame positions in the circumferential direction of the frame. According to such an aspect, it is possible to prevent the outer ends of the plurality of nested frames from overlapping in the stacking direction of the laminated body.

In the method for manufacturing a power storage module according to another form, in the laminating step, a plurality of bipolar electrode units are laminated by interposing a plurality of nests between different frames of the plurality of bipolar electrode units, and a plurality of nested frames are laminated. The outer ends are superposed in the laminating direction of the laminated body, and through holes are provided at each end of the plurality of nests so as to be superposed in the laminating direction of the laminated body. In this case, the work of removing the plurality of nests in the communication port forming step becomes easy. For example, the gripper of the automatic machine can grip the outer end of the nesting frame and remove the plurality of nesting in sequence, so that automation in the manufacture of the power storage module is promoted.

In the method for manufacturing a power storage module according to another form, in the heat welding step, the frame of the portion in contact with the nest is melted by heating the nest, and the end face of the seal around the communication port is heat welded. Even if it is difficult to perform sufficient heat welding on the seal end face around the communication port, by heating the nest and melting the frame of the part in contact with the nest, the seal end face around the communication port can be welded. Sufficient heat welding treatment can be applied.

In the method for manufacturing a power storage module according to another form, a hot plate, hot air, or a laser is used for heat welding of the seal end face in the heat welding step.

According to the present invention, there is provided a power storage module provided with a seal portion having a novel configuration and a method for manufacturing the same.

It is schematic cross-sectional view which shows embodiment of the power storage device including the power storage module. It is schematic cross-sectional view which shows the power storage module which comprises the power storage device of FIG. It is an exploded sectional view which shows the structure of the 1st seal part of the power storage module of FIG. It is sectional drawing which follows the IV-IV line of FIG. It is a flowchart which showed the procedure of manufacturing the power storage device of FIG. It is a figure which showed the state of the laminating process. It is a figure which showed the state of the heat welding process. It is sectional drawing which showed the state of the heat welding process. It is sectional drawing which showed the state of the communication opening formation process. It is a figure which showed the state of the communication port forming process of a different aspect. It is a figure which showed the state of the communication port forming process of a different aspect.

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.

An embodiment of the power storage device will be described with reference to FIG. The power storage device 10 shown in FIG. 1 is used as a battery for various vehicles such as forklifts, hybrid vehicles, and electric vehicles. The power storage device 10 includes a plurality of (three in this embodiment) power storage modules 12, but may include a single power storage module 12. The power storage module 12 is a bipolar battery. The power storage module 12 is a secondary battery such as a nickel hydrogen secondary battery or a lithium ion secondary battery, but may be an electric double layer capacitor. In the following description, a nickel-metal hydride secondary battery will be illustrated.

The plurality of power storage modules 12 can be laminated via a conductive plate 14 such as a metal plate. Seen from the stacking direction, the power storage module 12 and the conductive plate 14 have, for example, a rectangular shape. Details of each power storage module 12 will be described later. The conductive plates 14 are also arranged on the outside of the power storage modules 12 located at both ends in the stacking direction (Z direction) of the power storage modules 12. The conductive plate 14 is electrically connected to the adjacent power storage modules 12. As a result, the plurality of power storage modules 12 are connected in series in the stacking direction. In the stacking direction, the positive electrode terminal 24 is connected to the conductive plate 14 located at one end, and the negative electrode terminal 26 is connected to the conductive plate 14 located at the other end. The positive electrode terminal 24 may be integrated with the conductive plate 14 to be connected. The negative electrode terminal 26 may be integrated with the conductive plate 14 to be connected. The positive electrode terminal 24 and the negative electrode terminal 26 extend in a direction (X direction) intersecting the stacking direction. The positive electrode terminal 24 and the negative electrode terminal 26 can be used to charge and discharge the power storage device 10.

The conductive plate 14 can also function as a heat radiating plate for releasing the heat generated in the power storage module 12. By allowing a refrigerant such as air or gas to pass through the plurality of voids 14a provided inside the conductive plate 14, the heat from the power storage module 12 can be efficiently released to the outside. Each void 14a extends in a direction (Y direction) intersecting the stacking direction, for example. The conductive plate 14 is smaller than the power storage module 12 when viewed from the stacking direction, but may be the same as or larger than the power storage module 12.

The power storage device 10 may include a restraint member 16 that restrains the power storage modules 12 and the conductive plates 14 that are alternately stacked in the stacking direction. The restraint member 16 includes a pair of restraint plates 16A and 16B and connecting members (bolts 18 and nuts 20) that connect the restraint plates 16A and 16B to each other. An insulating film 22 such as a resin film is arranged between the restraint plates 16A and 16B and the conductive plate 14. Each of the restraint plates 16A and 16B is made of a metal such as iron. When viewed from the stacking direction, the restraint plates 16A and 16B and the insulating film 22 have, for example, a rectangular shape. The insulating film 22 is larger than the conductive plate 14, and the restraint plates 16A and 16B are larger than the power storage module 12. When viewed from the stacking direction, an insertion hole 16A1 through which the shaft portion of the bolt 18 is inserted is provided at a position outside the power storage module 12 at the edge portion of the restraint plate 16A. Similarly, when viewed from the stacking direction, an insertion hole 16B1 through which the shaft portion of the bolt 18 is inserted is provided at a position outside the power storage module 12 at the edge portion of the restraint plate 16B. When the restraint plates 16A and 16B have a rectangular shape when viewed from the stacking direction, the insertion holes 16A1 and the insertion holes 16B1 are located at the corners of the restraint plates 16A and 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 has the insulating film 22 attached to the conductive plate 14 connected to the positive electrode terminal 24. It is struck through. The bolt 18 is passed through the insertion hole 16A1 and the insertion hole 16B1 from one restraint plate 16A side toward the other restraint plate 16B side, for example. A nut 20 is screwed to the tip of a bolt 18 protruding from the other restraint plate 16B. As a result, the insulating film 22, the conductive plate 14, and the power storage module 12 are sandwiched and unitized, and a restraining load is applied in the stacking direction.

A power storage module constituting the power storage device will be described with reference to FIG. The power storage module 12 shown in FIG. 2 includes a laminated body 30 in which a plurality of bipolar electrodes 32 are laminated. When viewed from the stacking direction of the bipolar electrodes 32, the laminated body 30 has, for example, a rectangular shape. A separator 40 may be arranged between adjacent bipolar electrodes 32.

Each bipolar electrode 32 includes an electrode plate 34, a positive electrode 36 provided on the first surface 34c of the electrode plate 34, and a negative electrode 38 provided on the second surface 34d of the electrode plate 34. In the laminated body 30, the positive electrode 36 of one bipolar electrode 32 faces the negative electrode 38 of one of the bipolar electrodes 32 adjacent to each other in the stacking direction with the separator 40 interposed therebetween, and the negative electrode 38 of one bipolar electrode 32 has the separator 40. It faces the positive electrode 36 of the other bipolar electrode 32 that is adjacent to each other in the stacking direction.

In the stacking direction, an electrode plate 34 having a negative electrode 38 arranged on an inner side surface (lower surface in the drawing) is arranged at one end of the laminated body 30. The electrode plate 34 corresponds to the negative electrode side terminal electrode. In the stacking direction, an electrode plate 34 having a positive electrode 36 arranged on an inner side surface (upper surface in the drawing) is arranged at the other end of the laminated body 30. The electrode plate 34 corresponds to a positive electrode side terminal electrode. The negative electrode 38 of the negative electrode side terminal 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 terminal 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 adjacent conductive plates 14 (see FIG. 1).

The power storage module 12 includes a tubular resin portion (seal member) 50 extending in the stacking direction of the bipolar electrodes 32 and accommodating the laminated body 30. The resin portion 50 holds peripheral portions 34a of the plurality of electrode plates 34. The resin portion 50 is configured to surround the laminated body 30. The resin portion 50 has, for example, a rectangular shape when viewed from the stacking direction of the bipolar electrodes 32. That is, the resin portion 50 has, for example, a square tube shape.

The resin portion 50 is joined to the peripheral edge portion 34a of the electrode plate 34 and is joined to the peripheral edge portion 34a to hold the peripheral edge portion 34a. It has a second seal portion 54 provided on the outside of the. The second seal portion 54 is provided in a state of being sealed with the first seal portion 52.

The first sealing portion 52 forming the inner wall of the resin portion 50 is provided over the entire circumference of the peripheral edge portion 34a of the electrode plate 34 in the plurality of bipolar electrodes 32 (that is, the laminated body 30). The first sealing portion 52 is, for example, welded to the peripheral edge portion 34a of the electrode plate 34, and seals the peripheral edge portion 34a thereof. That is, the first seal portion 52 is joined to the peripheral edge portion 34a of the electrode plate 34. The peripheral edge portion 34a of the electrode plate 34 of each bipolar electrode 32 is held in a state of being embedded in the first seal portion 52. The peripheral edge portions 34a of the electrode plates 34 arranged at both ends of the laminated body 30 are also held in a state of being buried in the first seal portion 52. As a result, an internal space V is formed between the electrode plates 34, 34 adjacent to each other in the stacking direction, which is airtightly and watertightly partitioned by the electrode plates 34, 34 and the first seal portion 52. The internal space V contains an electrolytic solution (not shown) composed of an alkaline solution such as an aqueous potassium hydroxide solution. The term "volume of the internal space V" means the volume including the voids of the separator 40.

The outer peripheral surface 52a of the first seal portion 52 is a heat-welded surface. The second seal portion 54 constituting the outer wall of the resin portion 50 covers the outer peripheral surface 52a of the first seal portion 52 extending in the stacking direction of the bipolar electrodes 32. The inner peripheral surface 54a of the second sealing portion 54 is welded to, for example, the outer peripheral surface 52a of the first sealing portion 52, and seals the outer peripheral surface 52a. That is, the second seal portion 54 is joined to the outer peripheral surface 52a of the first seal portion 52. The welding surface (joining surface) of the second sealing portion 54 with respect to the first sealing portion 52 forms, for example, four rectangular planes.

The electrode plate 34 is a rectangular metal leaf made of, for example, nickel. The peripheral edge portion 34a of the electrode plate 34 is an uncoated region in which the positive electrode active material and the negative electrode active material are not coated. In the uncoated area, the electrode plate 34 is exposed. The uncoated area is buried and held in the first seal portion 52 constituting the inner wall of the resin portion 50. Examples of the positive electrode active material constituting the positive electrode 36 include nickel hydroxide. Examples of the negative electrode active material constituting the negative electrode 38 include a hydrogen storage alloy. The formation region of the negative electrode 38 on the second surface 34d of the electrode plate 34 may be one size larger than the formation region of the positive electrode 36 on the first surface 34c of the electrode plate 34.

The separator 40 is formed, for example, in the form of a sheet. The separator 40 has, for example, a rectangular shape. Examples of the material for forming the separator 40 include a porous film made of a polyolefin resin such as polyethylene (PE) and polypropylene (PP), a woven fabric made of polypropylene or the like, or a non-woven fabric. Further, the separator 40 may be reinforced with a vinylidene fluoride resin compound or the like.

The resin portion 50 (first seal portion 52 and second seal portion 54) is formed in a rectangular tubular shape by, for example, injection molding using an insulating resin. Examples of the resin material constituting the resin portion 50 include polypropylene (PP), polyphenylene sulfide (PPS), modified polyphenylene ether (modified PPE), and the like.

In the power storage device 10, the positive electrode 36 on the first surface 34c side of the electrode plate 34, the negative electrode 38 on the second surface 34d side of the adjacent electrode plate 34, the separator 40 between the positive electrode 36 and the negative electrode 38, and the first surface. A single layer of cells is composed of a resin portion 50 that seals the space between the 34c and the second surface 34d. The resin unit 50 regulates the movement of the gas and the electrolytic solution from one cell to another. As a result, insulation between adjacent cells is ensured.

Explaining the configuration of the first seal portion 52 in more detail with reference to FIG. 3, the first seal portion 52 has a structure in which a plurality of frame bodies 60 are laminated in the stacking direction. The frame body 60 has a thickness larger than the thickness of the separator 40 in the stacking direction. More specifically, the frame body 60 has a thickness larger than the sum of the thickness of the electrode plate 34 and the thickness of the separator 40 in the stacking direction.

The frame body 60 is joined to the peripheral edge portion 34a of the electrode plate 34 of the bipolar electrode 32, and is also joined to another frame body 60 adjacent in the stacking direction. The bipolar electrode unit 65 is composed of the bipolar electrode 32 and the frame body 60 joined to the peripheral edge portion 34a of the electrode plate 34 of the bipolar electrode 32. By joining the frame body 60 and another frame body 60, the frame body 60 defines the height of the internal space V (cell) formed between the electrode plates 34 and 34 adjacent to each other in the stacking direction. There is.

The frame body 60 has an inner peripheral portion 61 arranged on the first surface 34c side of the electrode plate 34 and joined to the first surface 34c, and an outer peripheral portion 62 continuously provided outside the inner peripheral portion 61. Including. The inner peripheral portion 61 and the outer peripheral portion 62 each correspond to the shape of the electrode plate 34, and have, for example, a rectangular shape. The inner peripheral portion 61 is joined to the first surface 34c of the electrode plate 34 by, for example, welding. That is, the inner peripheral portion 61 is joined to the first surface 34c of the electrode plate 34. The inner peripheral end 61c (see FIG. 3) of the inner peripheral portion 61 corresponds to the inner peripheral end 52c of the first seal portion 52. The thickness of the outer peripheral portion 62 is larger than the thickness of the inner peripheral portion 61, which is the thickness of the frame body 60. The outer peripheral surface (peripheral end surface of the frame body) 62d of the outer peripheral portion 62 corresponds to the outer peripheral end 52d (that is, the outer peripheral surface 52a) of the first seal portion 52.

The frame body 60 includes a first end surface 60a in the stacking direction and a second end surface 60b facing the first end surface 60a. The first end surface 60a of the frame body 60 is joined to the second end surface 60b of another frame body 60 adjacent in the stacking direction. The second end surface 60b of the frame body 60 is joined to the first end surface 60a of another frame body 60 adjacent in the stacking direction. The first end surface 60a and the second end surface 60b are joined to another frame body 60 in a planar shape in most of the circumferential direction (in the entire area except the communication port 70 described later). With this configuration, the frame body 60 defines the height of one cell in the power storage module 12. A rectangular annular step portion 68 connecting these is formed between the inner peripheral portion 61 and the outer peripheral portion 62 having different thicknesses in the stacking direction. The depth of the step portion 68 in the stacking direction is larger than the thickness of the separator 40. A peripheral edge portion 40a including an outer peripheral end 40d of the separator 40 is arranged on the step portion 68. That is, the step portion 68 formed in the frame body 60 faces the inside of the frame body 60, and provides a space for arranging the outer peripheral end 40d of the separator 40 in the first seal portion 52. .. For example, the peripheral edge portion 40a of the separator 40 is in contact with the surface 61a of the inner peripheral portion 61 (the surface opposite to the surface bonded to the first surface 34c). The separator 40 is within the height range of the frame body 60. A slight gap may be formed between the peripheral edge portion 40a and another electrode plate 34 adjacent to the separator 40 with the thickness of the negative electrode 38 separated.

The outer peripheral end 40d of the separator 40 may be flush with the peripheral end surface 62d of the frame body 60. The outer peripheral end 40d of the separator 40 may be the same as the outer peripheral end 52d of the first seal portion 52 or inside the outer peripheral end 52d and outside the inner peripheral end 52c of the first seal portion 52.

The structure of the resin portion 50, the bipolar electrode 32, and the separator 40 will be described with reference to FIG. As shown in FIG. 4, when viewed from the stacking direction, the peripheral edge portion 40a of the separator 40 overlaps the region where the first seal portion 52 is provided. In other words, when the separator 40 and the first seal portion 52 are projected in the stacking direction on a plane perpendicular to the stacking direction (XY plane), these projected images overlap (that is, overlap). The separator 40 reaches the region where the first seal portion 52 is provided. The outer peripheral end 40d of the separator 40 is located between the outer peripheral end 52d and the inner peripheral end 52c of the first seal portion 52. In FIG. 4, it is shown that a part of the separator 40 is broken so that the configuration of the first seal portion 52 can be easily understood.

Even in the region near the first seal portion 52 of the electrode plate 34, since the separator 40 is provided between the two adjacent electrode plates 34, the uncoated regions of the adjacent electrode plates 34 do not directly face each other. In two adjacent electrode plates 34, a separator 40 is always present between one uncoated area and the other uncoated area. The separator 40 provided so as to overlap the first seal portion 52 prevents two adjacent electrode plates 34 (particularly the uncoated region) from coming into contact with each other to cause a short circuit. The outer peripheral end 40d may be located between the outer peripheral end 52d and the inner peripheral end 52c of the first seal portion 52 over the entire circumference of the separator 40. The outer peripheral end 40d may be located between the outer peripheral end 52d and the inner peripheral end 52c of the first seal portion 52 in a part of the separator 40 in the circumferential direction. In the circumferential direction of the separator 40, the larger the separator 40 overlaps with the first seal portion 52, the more reliably the occurrence of a short circuit can be prevented.

As shown in FIG. 4, between the frame bodies 60 adjacent to each other in the stacking direction, a communication port 70 penetrating the inside and outside of the frame body 60 is formed at one place in the circumferential direction. Specifically, the communication port 70 penetrates the first seal portion 52 in a direction orthogonal to the stacking direction. The communication port 70 is a portion where adjacent frame bodies 60 are not partially joined to each other in the stacking direction. The communication port 70 can be used as a liquid injection port (electrolyte solution injection port) for injecting the electrolytic solution into the internal space V of the first seal portion 52. Further, the communication port 70 can be used as a pressure adjusting valve (for example, a degassing safety valve that opens when the internal pressure exceeds a predetermined value) that opens and closes according to the internal pressure in the first seal portion 52. In the present embodiment, the pressure adjusting unit 75 is provided so as to communicate with the communication port 70, and the pressure adjusting unit 75 assists or complements the function of the communication port 70 as a pressure adjusting valve. The communication port 70 can be used as both or one of the electrolyte injection port and the pressure regulating valve.

Hereinafter, the procedure for manufacturing the power storage module 12 will be described with reference to FIGS. 5 to 9.

When manufacturing the power storage module 12, first, as the laminating step S1, a plurality of bipolar electrode units 65 are laminated via the separator 40. At this time, the frame bodies 60 adjacent to each other in the stacking direction are joined by welding or the like. In the laminating step S1, as shown in FIG. 6, a nesting 80 for forming the above-mentioned communication port 70 is interposed between the frame bodies 60 adjacent to each other in the laminating direction. At this time, the nesting 80 is interposed so as to extend from the inside of the frame to the outside of the frame at right angles to the stacking direction. The nesting 80 is, for example, a monospaced strip-shaped film member. The constituent material of the nest 80 may be any material having heat resistance to such an extent that it has resistance to the treatment temperature in the heat welding step S2 described later, and is a metal material as an example.

Nesting 80s are arranged between adjacent frame bodies 60 in the stacking direction. When the nesting 80 is arranged at the same position in the circumferential direction of the frame body 60, there is a problem that only the thickness of the portion where the nesting 80 is arranged becomes extremely thick as compared with the other portions. Therefore, the nesting 80 is arranged. The positions to be nested are dispersed with respect to the circumferential direction of the frame body 60. In the present embodiment, the positions where the nesting 80s are arranged are periodically dispersed at eight locations with respect to the circumferential direction of the frame body 60, and the nesting 80s overlap every eight layers at each location as shown in the cross-sectional view of FIG. ing.

The plurality of nests 80 arranged at the same positions in the circumferential direction of the frame body 60 are arranged so that the respective end portions 80a on the outer side of the frame do not overlap in the stacking direction. In the present embodiment, the three nesting 80A to 80C arranged in order from the top in the stacking direction, each end 80a on the outside of the frame is the extending direction of the nesting 80 (that is, the direction crossing the frame body 60. FIG. It is shifted in the left-right direction). Specifically, the positions of the ends 80b inside the frame of the three nests 80A to 80B are the same, but the lengths of the three nests 80A to 80B in the extending direction are different, so that the three nests 80A to 80B are oriented from the frame 60 to the outside of the frame. The protruding lengths are different. More specifically, since the nest 80A located on the upper side is shorter than the length of the nest 80B located in the middle, the protruding length of the nest 80A is the shortest, and the nest 80C located on the lower side is shorter than the length of the nest 80B located in the center. The nesting 80C has the longest protruding length because it is also long. That is, the protruding lengths of the three nests 80A to 80C gradually increase toward the bottom.

After the laminating step S1, as the heat welding step S2, the outer peripheral surface 52a (seal end surface) of the first sealing portion 52 composed of the peripheral end surfaces 62d of the frame bodies 60 adjacent to each other in the laminating direction is heat welded. In the present embodiment, since the first sealing portion 52 has four outer peripheral surfaces 52a, a heat welding step is performed on each of the four outer peripheral surfaces 52a. On the outer peripheral surface 52a of the first seal portion 52, each nest 80 projects in a direction orthogonal to the outer peripheral surface 52a and is arranged in parallel.

The heat welding step S2 can be performed by applying a high temperature hot plate 85 to the outer peripheral surface 52a. The temperature of the hot plate 85 may be any temperature as long as the frame 60 melts, and is, for example, about 200 ° C. The material constituting the hot plate 85 is, for example, a metal material.

As shown in FIG. 7, the hot plate 85 has a flat plate shape, and through holes 86 are provided in portions corresponding to the three nests 80. The cross-sectional dimension of each through hole 86 is designed to be slightly larger than the cross-sectional dimension of the nesting 80 (the dimension in the cross section parallel to the outer peripheral surface 52a). By providing the through hole 86 in the hot plate 85, as shown in FIG. 8, when the hot plate 85 is applied to the outer peripheral surface 52a, the nesting 80 is inserted into the through hole 86, so that the nesting 80 is hindered by the nesting 80. The hot plate 85 can be applied to the outer peripheral surface 52a without any need.

As shown in FIG. 8, by applying the heat plate 85 to the outer peripheral surface 52a, the peripheral end surface 62d and the outer peripheral portion 62 of the frame body 60 are melted to a certain depth, and the peripheral end surfaces 62d of the adjacent frame bodies 60 are brought into contact with each other. It becomes a welded heat-welded surface.

In the heat welding step S2, each nest 80 may be heated. By heating the nest 80, the frame 60 of the portion in contact with the nest 80 (for example, the portion of reference numeral P in FIG. 8 for the nest 80C) is melted. In order to insert the nest 80 into the through hole 86 of the hot plate 85, it is necessary to design the size of the communication port 70 to be larger than the size of the nest 80. A region where the hot plate 85 does not contact may occur in a part of 52a. In such a case, the nesting 80 is heated to melt the frame 60 of the portion in contact with the nesting 80, so that the outer peripheral surface 52a of the region not in contact with the hot plate 85 (that is, the outer peripheral surface around the communication port 70). Can also be a heat welded surface.

After the heat welding step S2, as a communication port forming step S3, a communication port 70 is provided on the heat-welded outer peripheral surface 52a. Specifically, each nest 80 is removed from the first seal portion 52 on which the outer peripheral surface 52a is heat-welded, and the portion from which the nest 80 is removed becomes the communication port 70. In the present embodiment, when removing the nest 80, an automatic machine (not shown) is used, and as shown in FIG. 9, the gripper 90 of the automatic machine grips the end portion 80a on the outer side of the frame of the nest 80. More specifically, the gripper 90 has a pair of chucks 92 that can move in the thickness direction of the nesting 80, and by moving the pair of chucks 92, the end portion 80a on the outer side of the frame of the nesting 80 is thickened. Nest from the direction. In the present embodiment, the gripper 90 of the automatic machine removes the three nests 80 in the order of the lower nest 80C, the middle nest 80B, and the upper nest 80A. As described above, the protruding lengths of the three nests 80A to 80B gradually increase toward the bottom. Therefore, by removing the three nests 80A to 80B in order from the lower nest 80C, the nest 80 to be gripped by the gripper 90 ( For example, a situation in which the nesting 80 (for example, the nesting 80B) other than the nesting 80C) is contacted is avoided.

As described above, according to the power storage module 12 and its manufacturing method described above, a plurality of frames constituting the first seal portion 52 (seal portion) are formed by heat welding the outer peripheral surface 52a (seal end surface). The relative positional deviation of 60 is suppressed. Therefore, when the communication port 70 is used as an electrolytic solution injection port or a degassing safety valve, the situation where those functions are impaired is effectively suppressed.

When the communication port 70 is provided by using the nesting 80 described above, the dimension of the communication port 70 is substantially the same as the outer diameter dimension of the nesting 80. Therefore, the communication is performed by adjusting the outer diameter dimension of the nesting 80. The dimensions of the mouth 70 can be easily adjusted. Further, the position of the communication port 70 can be easily adjusted by adjusting the position where the nest 80 is arranged in the circumferential direction of the frame body 60. Further, by increasing the dimensional accuracy of the nest 80, the dimensional accuracy of the communication port 70 can be improved.

Work for removing the nesting 80A, 80B, 80C in the communication port forming step S3 by preventing the outer end portions 80a of the nesting 80A, 80B, 80C from overlapping in the stacking direction as in the above-described embodiment. Becomes easier. By removing the nest 80 using the gripper 90 of the automatic machine, automation in the manufacture of the power storage module 12 can be promoted. As a mode in which the outer end portions 80a of the plurality of nests 80 are not overlapped in the stacking direction, the lengths of the plurality of nesting 80s in the extending direction are the same, and the position of the inner end portion 80b of the frame is the same. The ends 80a of the plurality of nests 80 do not overlap in the stacking direction even if the protrusion lengths of the plurality of nests 80 are different. Further, as shown in FIG. 10, even in a mode in which the plurality of nesting 80s are arranged at different positions (frame body positions) with respect to the circumferential direction of the frame body 60, the outer end portions 80a of the plurality of nesting 80s are in the stacking direction. Do not superimpose. When a plurality of nesting 80s are arranged at different positions with respect to the circumferential direction of the frame body 60, as shown in FIG. 10, even if the protruding lengths of the nesting 80s are the same, the end portions 80a on the outside of each frame are formed. Do not overlap in the stacking direction. Also in the embodiment shown in FIG. 10, each nesting 80 projects in a direction orthogonal to the outer peripheral surface 52a and is arranged in parallel.

The outer end portions 80a of the plurality of nesting 80s may be overlapped in the stacking direction. In the embodiment shown in FIG. 11, the three nesting 80s are arranged at the same position with respect to the circumferential direction of the frame body 60, and have the same protrusion length protruding from the frame body 60 in the outward direction of the frame, and are outside the frame. Each end 80a of the above is overlapped in the stacking direction. In this way, even if the outer end portions 80a of the plurality of nesting 80s are overlapped in the stacking direction, the nesting 80 can be manually removed by, for example, an operator. For automation, for example, as shown in FIG. 11, a through hole 81 may be provided at the end 80a of each nest 80D so as to overlap in the stacking direction. In this case, after the pin-shaped member 95 operated by the automatic machine is penetrated through all the through holes 81, the pin-shaped member 95 is moved in the direction away from the outer peripheral surface 52a, so that all the nesting 80Ds are removed at the same time. be able to.

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

For example, when the outer peripheral surface 52a of the first seal portion 52 is used as a heat welding surface, hot air or a laser may be used instead of the hot plate 85. Further, the outer peripheral surface 52a of the first seal portion 52 can be made into a heat welding surface by a combination of a hot plate, hot air, a lamp (infrared lamp), induction heating, and a laser. The above-mentioned hot plate 85, hot air, lamp (infrared lamp), induction heating, laser, or the like can also be used for heating the nest 80.

10 ... power storage device, 12 ... power storage module, 32 ... bipolar electrode, 34 ... electrode plate, 36 ... positive electrode, 38 ... negative electrode, 40 ... separator, 50 ... resin part, 52 ... first seal part, 52a ... outer peripheral surface, 54 ... 2nd seal part, 60 ... frame body, 62 ... outer peripheral part, 62d ... peripheral end surface, 65 ... bipolar electrode unit, 70 ... communication port, 75 ... pressure adjustment unit, 80, 80A, 80B, 80C, 80D ... nested, 80a, 80b ... end, 81 ... through hole, 85 ... hot plate, 86 ... through hole, V ... internal space.

Claims (4)

A laminate in which a plurality of bipolar electrodes including an electrode plate, a positive electrode provided on one surface of the electrode plate, and a negative electrode provided on the other surface of the electrode plate are laminated via a separator.
The frame extends in the stacking direction of the laminated body so as to accommodate the laminated body, and the frame body joined to the peripheral edge of each electrode plate of the plurality of bipolar electrodes is superposed in the stacking direction of the laminated body. It is a method of manufacturing a power storage module including a seal member having a cylindrical seal portion.
A laminating step of laminating a plurality of bipolar electrode units having the frame bonded to the peripheral edge of each electrode plate of the plurality of bipolar electrodes via the separator.
A heat welding step of heat-welding the peripheral end faces of adjacent frame bodies in the laminating direction of the laminated body to provide a heat-welding surface on the seal end face of the seal portion.
A communication port that penetrates the seal portion between adjacent frames in the stacking direction in a direction orthogonal to the stacking direction and is surrounded by the heat welding surface on the seal end surface of the seal portion. Including the communication port forming step to be provided
In the laminating step, the plurality of bipolar electrode units are laminated by interposing a nest extending from the inside of the frame to the outside of the frame between adjacent frames in the laminating direction.
In the heat welding step, the peripheral end faces of adjacent frames are heat-welded to each other with the nesting interposed therebetween.
In the communication port forming step, the nest is removed from between the adjacent frames.
In the laminating step, the plurality of bipolar electrode units are laminated by interposing the plurality of nests between different frames of the plurality of bipolar electrode units.
The outer ends of the plurality of nested frames are not overlapped in the stacking direction of the laminated body, and the layers are not overlapped with each other.
In the laminating step, the plurality of nests are interposed so as to project from the same frame position to the outside of the frame in the laminating direction of the laminated body and to have different protrusion lengths protruding from the frame in the out-of-frame direction .
The communication port, that acts as at least one vent safety valve that opens when the internal pressure of the electrolyte injection hole and in the seal portion for injecting the electrolyte into the interior space of the sealing portion exceeds a predetermined value , Manufacturing method of power storage module. A laminate in which a plurality of bipolar electrodes including an electrode plate, a positive electrode provided on one surface of the electrode plate, and a negative electrode provided on the other surface of the electrode plate are laminated via a separator.
The frame extends in the stacking direction of the laminated body so as to accommodate the laminated body, and the frame body joined to the peripheral edge of each electrode plate of the plurality of bipolar electrodes is superposed in the stacking direction of the laminated body. It is a method of manufacturing a power storage module including a seal member having a cylindrical seal portion.
A laminating step of laminating a plurality of bipolar electrode units having the frame bonded to the peripheral edge of each electrode plate of the plurality of bipolar electrodes via the separator.
A heat welding step of heat-welding the peripheral end faces of adjacent frame bodies in the laminating direction of the laminated body to provide a heat-welding surface on the seal end face of the seal portion.
A communication port that penetrates the seal portion between adjacent frames in the stacking direction in a direction orthogonal to the stacking direction and is surrounded by the heat welding surface on the seal end surface of the seal portion. Including the communication port forming step to be provided
In the laminating step, the plurality of bipolar electrode units are laminated by interposing a nest extending from the inside of the frame to the outside of the frame between adjacent frames in the laminating direction.
In the heat welding step, the peripheral end faces of adjacent frames are heat-welded to each other with the nesting interposed therebetween.
In the communication port forming step, the nest is removed from between the adjacent frames.
In the laminating step, the plurality of bipolar electrode units are laminated by interposing the plurality of nests between different frames of the plurality of bipolar electrode units.
The outer ends of the frame of the plurality of nests are overlapped in the stacking direction of the laminated body, and each end of the plurality of nests is provided with a through hole which is superimposed in the stacking direction of the laminated body .
The communication port, that acts as at least one vent safety valve that opens when the internal pressure of the electrolyte injection hole and in the seal portion for injecting the electrolyte into the interior space of the sealing portion exceeds a predetermined value , Manufacturing method of power storage module. In the heat welding step, the frame body in a portion in contact with the nest is melted by heating the nest, and the heat welded surface is provided around the communication port on the seal end surface of the seal portion. Alternatively, the method for manufacturing a power storage module according to 2. The method for manufacturing a power storage module according to any one of claims 1 to 3, wherein a hot plate, hot air, or a laser is used for heat welding in the heat welding step.

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