JP2021039873A - Manufacturing installation of power storage module - Google Patents

Abstract

To provide a manufacturing installation of power storage module capable of shortening the welding time, while securing the encapsulation performance of an encapsulator.SOLUTION: A manufacturing installation 50 is equipped with a restraint part 51 for holding a unit laminate 30 including an electrode laminate and multiple first encapsulation parts provided, respectively, at the peripheral parts of electrode plate of multiple electrodes, in the lamination direction D1, and a welding device 52 for welding the end face 30c of the unit laminate 30 constituted of the laminated multiple first encapsulation parts by ultrasonic welding. The welding device 52 is equipped with a horn 56 for applying supersonic vibration to the end face 30c, the horn 56 has a pressing surface 56a for pressing the end face 30c in the direction D2, and recesses 56b which are placed between two electrodes adjoining in the lamination direction D1, out of the multiple electrodes, and into which communication hole formation members 40 projecting from the end face 30c in the direction D2 can be fitted, are provided in the pressing surface 56a.SELECTED DRAWING: Figure 5

Description

The present disclosure relates to an apparatus for manufacturing a power storage module.

A power storage module including a bipolar electrode having a positive electrode formed on one surface of an electrode plate and a negative electrode formed on the other surface is known (see, for example, Patent Document 1). The power storage module described in Patent Document 1 includes a laminate in which bipolar electrodes and separators are alternately laminated along the stacking direction. On the side surface of the laminated body, a sealing body for sealing between the bipolar electrodes adjacent to each other in the stacking direction is provided, and the electrolytic solution is housed in the internal space formed between the bipolar electrodes. The sealing body is provided with a communication hole for injecting the electrolytic solution into the internal space.

JP-A-2018-174079

In the procedure for manufacturing the power storage module described in Patent Document 1, a plurality of bipolar electrodes having a frame (first sealing portion) bonded to the peripheral edge of the electrode plate are laminated via a separator. At this time, with respect to the portion of the first sealing portion that forms the communication hole for injecting the electrolytic solution into the internal space, the communication hole forming members for forming the communication hole are adjacent to each other in the first sealing in the stacking direction. It is placed between the stops. Then, by pressing a high-temperature hot plate against the first sealing portion forming the end face of the laminated body, the first sealing portions adjacent to each other in the stacking direction are heat-welded to each other. In such hot plate welding, if the hot plate is pulled away from the end face of the laminate before the melted first sealing portion is completely solidified, the molten first sealing portion is pulled by the hot plate. The end face of the laminate may be rough. When the end face of the first sealing portion is rough and the second sealing portion is formed around the first sealing portion by injection molding, the rough surface is supplied from the injection molding machine to the resin of the second sealing portion. There is a risk of impeding the flow of material and degrading the sealing performance of the molded encapsulant. On the other hand, in the hot plate welding device, it takes a very long time to cool the hot plate once it has reached a high temperature to a predetermined temperature or lower. If it is separated from the laminate, the time required for the welding process becomes long, which may lead to a decrease in productivity.

The present disclosure describes a power storage module manufacturing apparatus capable of shortening the welding time while ensuring the sealing performance of the sealed body.

The power storage module manufacturing apparatus according to one aspect of the present disclosure includes an electrode laminate including a plurality of electrodes laminated in the first direction and a plurality of first seals provided on the peripheral edges of the electrode plates of the plurality of electrodes. It is provided with a restraint portion for sandwiching the unit laminate including the portion in the first direction, and a welding device for welding the end face of the unit laminate composed of the plurality of laminated first sealing portions by ultrasonic welding. .. The welding device includes a horn that applies ultrasonic vibration to the end face. The horn has a pressing surface that presses the end face in a second direction that intersects the first direction. The pressing surface is provided between two electrodes adjacent to each other in the first direction among the plurality of electrodes, and is provided with a recess into which a communication hole forming member projecting from the end surface in the second direction can be fitted.

In this power storage module manufacturing apparatus, the end face of the unit laminate is welded by ultrasonic welding by applying ultrasonic vibration to the end face of the unit laminate with a horn. In ultrasonic welding, the horn is not heated, so it cools as soon as the ultrasonic vibration is stopped. Therefore, as compared with hot plate welding, the time required for the molten end face to solidify can be shortened, and the welding time can be shortened. Further, the horn has a pressing surface provided with a recess into which a communication hole forming member protruding from the end surface of the unit laminate can be fitted. In ultrasonic welding, the temperature of the horn is sufficiently lower than the temperature of the hot plate, so that even if the communication hole forming member is fitted in the recess of the horn, the temperature of the communication hole forming member is suppressed from becoming high. Therefore, it is possible to prevent the portion of the unit laminate that is in contact with the communication hole forming member from melting, and to secure the sealing performance of the first sealing portion. As a result, it is possible to shorten the welding time while ensuring the sealing performance of the sealed body.

The length of the horn in the first direction may be longer than the length of the unit laminate sandwiched by the restraint portion in the first direction. In this case, since the pressing surface of the horn can be pressed against the entire end surface of the unit laminate, it is possible to improve the end surface quality of the unit laminate.

The welding device may further include a drive unit that moves the horn in the second direction. The driving unit may move the horn toward the end surface until the distance between the restraining unit and the pressing surface in the second direction becomes a predetermined distance. In this case, since the horn is separated from the restraint portion, it is possible to prevent the generation of foreign matter generated by the rubbing between the horn and the restraint portion.

The manufacturing apparatus may further include a removing portion for removing burrs generated by ultrasonic welding of the end faces. If burrs are generated on the end faces of the unit laminate, the burrs may peel off in the injection molding for forming the second sealing portion, which may hinder the flow of the molten resin material. According to the above configuration, burrs generated by ultrasonic welding are removed, so that the quality of the second resin portion can be ensured.

The restraint portion may include a first clamp member and a second clamp member facing each other in the first direction. The first clamp member may include a main body portion and a tip portion that is detachably provided on the main body portion and has a surface facing the pressing surface. In this case, the possibility that the first clamp portion is cut together with the burr can be reduced by removing the tip portion of the first clamp member from the main body portion. This makes it possible to suppress the generation of foreign matter from the first clamp portion.

The recess may include a first portion and a second portion arranged in the second direction. The second portion may be farther from the pressing surface than the first portion. The length of the first part in the first direction may be longer than the length of the second part in the first direction. In this case, the generation of burrs can be suppressed by the flow of the first sealing portion in the molten state into the first portion.

The first portion may have a tapered shape in which the length in the first direction becomes shorter as the distance from the pressing surface increases. In this case, the first portion can function as a guide for guiding the communication hole forming member to the recess. Therefore, it is possible to improve the workability of inserting the communication hole forming member into the recess.

According to the present disclosure, the welding time can be shortened while ensuring the sealing performance of the sealed body.

FIG. 1 is a schematic cross-sectional view showing an example of a power storage device including a power storage module according to an embodiment. FIG. 2 is a schematic cross-sectional view showing an example of the internal configuration of the power storage module shown in FIG. FIG. 3 is a process diagram showing an example of the manufacturing method of the power storage module shown in FIG. FIG. 4 is a perspective view for explaining a process of forming a unit laminate. FIG. 5 is a diagram for explaining a manufacturing apparatus for a power storage module used in the step of welding the first sealing portion. FIG. 6 is a diagram showing a manufacturing apparatus for a power storage module according to a comparative example. FIG. 7 is a diagram showing a modified example of the power storage module manufacturing apparatus. 8 (a) to 8 (c) are views for explaining a step of welding end faces using the manufacturing apparatus shown in FIG. 7. FIG. 9 is a diagram showing another modification of the power storage module manufacturing apparatus. FIG. 10 is a diagram showing still another modification of the power storage module manufacturing apparatus.

Hereinafter, one embodiment 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 an example of 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 (four in the present embodiment) power storage modules 4 and a plurality of (three in the present embodiment) conductive plates 5. The plurality of power storage modules 4 are stacked along the stacking direction D1 (first direction). The power storage module 4 is a bipolar battery and has a rectangular shape when viewed from the stacking direction D1. 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 D1 are electrically connected to each other via a conductive plate 5. Here, the power storage modules 4 are arranged at the laminated ends of the module laminate 2, and the conductive plates 5 are arranged between the two power storage modules 4 adjacent to each other in the stacking direction D1. A conductive plate P different from the conductive plate 5 is arranged on the outside of the power storage module 4 located at the laminated end in the stacking direction D1. The positive electrode terminal 6 is connected to the conductive plate P located at the lower end of the stack. The negative electrode terminal 7 is connected to the conductive plate P 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 P, for example, in the direction D2 (second direction) intersecting (orthogonal) with the stacking direction D1. The positive electrode terminal 6 and the negative electrode terminal 7 charge and discharge the power storage device 1.

The conductive plate 5 is provided with a plurality of flow paths 5a. The flow path 5a is a through hole for passing a cooling fluid such as air. The flow path 5a penetrates the conductive plate 5 in the direction D3 (see FIG. 4) that intersects (orthogonally) the stacking direction D1 and the direction D2, respectively, and extends along the direction D3. The plurality of flow paths 5a are arranged along the direction D2. The conductive plate 5 functions as a connecting member that electrically connects two power storage modules 4 adjacent to each other in the stacking direction D1, and also by circulating a cooling fluid through these flow paths 5a, the power storage module 4 It also has a function as a heat radiating plate that releases the heat generated in. In the example of FIG. 1, the area of the conductive plate 5 seen from the stacking direction D1 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, 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 D1. The restraint member 3 includes a pair of end plates 8 that sandwich the module laminate 2 in the stacking direction D1, 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 areas of the power storage module 4, the conductive plate 5, and the conductive plate P as viewed from the stacking direction D1. An insulating plate F having electrical insulation is provided between the end plate 8 and the conductive plate P. The insulating plate F insulates between the end plate 8 and the conductive plate P.

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, the conductive plate 5, and the conductive plate P are sandwiched by the pair of end plates 8 and unitized as the module laminate 2. A restraining load is applied to the module laminate 2 in the stacking direction D1.

Next, the configuration of the power storage module 4 will be described in detail. FIG. 2 is a schematic cross-sectional view showing an example of the internal configuration of the power storage module shown in FIG. As shown in FIG. 2, the power storage module 4 includes an electrode laminate 11 and a resin sealant 12 that seals the electrode laminate 11. The electrode laminate 11 is composed of a plurality of electrodes laminated along the stacking direction D1 via a separator 13. These plurality of electrodes include a negative electrode terminating electrode 18, a positive electrode terminating electrode 19, and a plurality of bipolar electrodes 14 provided between the negative electrode terminating electrode 18 and the positive electrode terminating electrode 19.

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 and methyl cellulose. The separator 13 may be reinforced with a vinylidene fluoride resin compound.

The negative electrode terminal electrode 18, the plurality of bipolar electrodes 14, and the positive electrode terminal electrode 19 are laminated in this order via the separator 13 along the stacking direction D1. 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 coating the upper surface 15a with the positive electrode active material. 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 the stacking direction D1 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 the stacking direction D1 with the separator 13 interposed therebetween.

The negative electrode terminal electrode 18 is arranged at one end of the electrode laminate 11 in the stacking direction D1. 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 D1 via the separator 13. One of the conductive plates 5 or the conductive plate P (see FIG. 1) 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 of the electrode laminate 11 in the stacking direction D1 opposite to one end. 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 D1 via the separator 13. The other conductive plate 5 or the conductive plate P (see FIG. 1) 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.

The sealing body 12 is formed in a rectangular tubular shape as a whole by, for example, an insulating resin. The sealing body 12 is provided on the side surface 11a of the electrode laminated body 11 so as to surround the peripheral edge portion 15c of the electrode plate 15. The sealing body 12 holds the peripheral edge portion 15c on the side surface 11a. The sealing body 12 extends to the side surface 11a along the stacking direction D1 and the plurality of first sealing portions 21 provided on the peripheral edges 15c of the electrode plates 15 of the plurality of electrodes, respectively, and the first sealing portion 21. It has a second sealing portion 22 provided around it. The first sealing portion 21 and the second sealing portion 22 are made of an insulating resin having alkali resistance. Examples of the constituent materials of the first sealing portion 21 and the second sealing portion 22 include polypropylene (PP), polyphenylene sulfide (PPS), modified polyphenylene ether (modified PPE), and the like.

The first sealing portion 21 is continuously provided on the upper surface 15a of the electrode plate 15 over the entire circumference of the peripheral edge portion 15c, and has a rectangular frame shape when viewed from the stacking direction D1 (see FIG. 4). In the present embodiment, the first sealing portion 21 is provided not only on the electrode plate 15 of the bipolar electrode 14, but also on the electrode plate 15 of the negative electrode terminal 18 and the electrode plate 15 of the positive electrode 19.

The first sealing portion 21 has a first portion 21a and a second portion 21b. The first portion 21a is provided on the upper surface 15a and overlaps with the electrode plate 15 when viewed from the stacking direction D1. The second portion 21b is integrally formed with the first portion 21a and projects outward from the edge of the electrode plate 15 when viewed from the stacking direction D1. The tip portion of the second portion 21b is held by the second sealing portion 22. The thickness of the first portion 21a is thinner than the thickness of the second portion 21b and is equal to or greater than the thickness of the positive electrode 16. A stepped surface 21c extending in the stacking direction D1 is formed between the first portion 21a and the second portion 21b.

An outer edge portion of the separator 13 is arranged on the upper surface of the first portion 21a. Seen from the stacking direction D1, the first portion 21a and the outer edge portion of the separator 13 overlap each other. The outer edge portion of the separator 13 is fixed to the upper surface of the first portion 21a at a plurality of locations arranged along the outer edge of the separator 13 by, for example, welding. The outer edge of the separator 13 may be in contact with the stepped surface 21c or may be separated from the stepped surface 21c. In the present embodiment, the height of the stepped surface 21c (length in the stacking direction D1) is equal to or greater than the sum of the thickness of the separator 13 and the thickness of the negative electrode 17. The outer edge portions of the first sealing portion 21 are bonded to each other by welding.

The second sealing portion 22 has overhang portions 22e at both ends in the stacking direction D1. One overhang portion 22e projects toward the inner edge of the first sealing portion 21 at one end in the stacking direction D1 and is welded to the upper surface 15a of the electrode plate 15 constituting the negative electrode terminal electrode 18. It is bound to 21. The other overhang portion 22e projects toward the inner edge of the first sealing portion 21 at the other end of the stacking direction D1 and is welded to the lower surface 15b of the electrode plate 15 constituting the positive electrode terminal electrode 19. It is connected to the part 21. The overhang lengths of one and the other overhang portions 22e are equal to each other, and the tips 22f of these overhang portions 22e are formed on the overlapping portion K between the electrode plate 15 and the first sealing portion 21 when viewed from the stacking direction D1. It is located so that it overlaps.

The second sealing portion 22 is provided outside the electrode laminate 11 and the first sealing portion 21, and constitutes an outer wall (housing) of the power storage module 4. The second sealing portion 22 is formed by, for example, injection molding of a resin, and extends along the stacking direction D1 over the entire length of the electrode laminate 11. The second sealing portion 22 has a rectangular frame shape extending in the axial direction with the stacking direction D1 as the axial direction. The second sealing portion 22 is welded to the outer edge portion of the first sealing portion 21 by heat during injection molding, for example.

The sealing body 12 (first sealing portion 21 and second sealing portion 22) seals the internal space V formed between two electrodes adjacent to each other. More specifically, the second sealing portion 22, together with the first sealing portion 21, is located between two bipolar electrodes 14 adjacent to each other along the stacking direction D1 and negative electrode terminations adjacent to each other along the stacking direction D1. The electrodes 18 and the bipolar electrodes 14 are sealed, and the positive electrode termination electrodes 19 and the bipolar electrodes 14 adjacent to each other along the stacking direction D1 are sealed. As a result, an internal space V that is airtightly partitioned between the two adjacent 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, is provided. It is formed. An aqueous electrolytic solution (not shown) containing an alkaline solution such as an aqueous potassium hydroxide solution is housed in the internal space V. The electrolytic solution is impregnated in the separator 13, the positive electrode 16, and the negative electrode 17.

Next, a method of manufacturing the power storage module 4 will be described with reference to FIGS. 3 to 5. FIG. 3 is a process diagram showing an example of the manufacturing method of the power storage module shown in FIG. FIG. 4 is a perspective view for explaining a process of forming a unit laminate. FIG. 5 is a diagram for explaining a manufacturing apparatus used in the step of welding the first sealing portion. As shown in FIG. 3, the method for manufacturing the power storage module 4 includes steps S1 to S8.

First, step S1 for preparing a plurality of electrodes is performed. In step S1, a plurality of electrodes including a negative electrode terminal electrode 18, a positive electrode terminal electrode 19, and a plurality of bipolar electrodes 14 are prepared.

Subsequently, the step S2 of forming the first sealing portion 21 on the peripheral edge portion 15c of each electrode plate 15 of the plurality of electrodes (negative electrode terminal electrode 18, positive electrode terminal electrode 19, and plurality of bipolar electrodes 14) is performed. In step S2, a frame-shaped first sealing portion 21 is formed on the peripheral edge portion 15c of the upper surface 15a of each electrode plate 15. For example, the first sealing portion 21 formed in advance by injection molding or the like is attached to the peripheral edge portion 15c by welding. In step S1, the first sealing portion 21 in which the recess 21d is formed in advance is used. The recess 21d is a portion provided on the upper surface of the first sealing portion 21 and extends in the direction D2 and is recessed in the stacking direction D1. The length of the recess 21d in the direction D3 is set to the length of the communication hole forming member 40 (see FIG. 4) described later in the direction D3. The depth of the recess 21d (length in the stacking direction D1) is set to the thickness of the communication hole forming member 40 (length in the stacking direction D1).

Subsequently, the step S3 of attaching the separator 13 to the first sealing portion 21 is performed. In the present embodiment, the outer edge portion of the separator 13 is arranged on the upper surface of the first portion 21a of the first sealing portion 21 provided on the bipolar electrode 14 and the positive electrode terminal electrode 19. After that, the outer edge portion of the separator 13 is fixed to the first portion 21a by, for example, welding at a plurality of locations arranged along the outer edge portion of the separator 13.

Subsequently, the step S4 for forming the unit laminated body 30 is performed. The unit laminate 30 includes a plurality of first seals provided on the peripheral edge portion 15c of the electrode plate 15 of the electrode laminate 11 and the plurality of electrodes (negative electrode termination electrode 18, positive electrode termination electrode 19, and plurality of bipolar electrodes 14), respectively. Includes a stop 21.

In step S4, the plurality of electrodes are laminated in the stacking direction D1 via the separator 13 so that the plurality of bipolar electrodes 14 are located between the negative electrode terminal electrode 18 and the positive electrode terminal electrode 19. Specifically, as shown in FIG. 4, the positive electrode terminal electrode 19 provided with the first sealing portion 21 and the separator 13 is placed on a stacking jig (not shown). After that, the communication hole forming member 40 is fitted into the recess 21d of the first sealing portion 21 provided on the positive electrode terminal electrode 19, and the communication hole forming member 40 is arranged, and the first sealing portion 21 and the separator 13 are arranged. The bipolar electrode 14 provided with the above is laminated on the positive electrode terminal electrode 19. The communication hole forming member 40 is a rectangular plate-shaped member. The communication hole forming member 40 is made of, for example, a metal such as stainless steel. The communication hole forming member 40 has a width (length in direction D3) that is about the same as or slightly smaller than the width of the recess 21d (length in direction D3). The tip 40a of the communication hole forming member 40 may be in contact with the outer edge of the separator 13 or may be separated from the outer edge of the separator 13.

Similarly, the communication hole forming member 40 is fitted into the recess 21d of the first sealing portion 21 formed in the uppermost bipolar electrode 14 mounted on the stacking jig, and the communication hole forming member 40 is fitted onto the bipolar electrode 14. The bipolar electrode 14 provided with the first sealing portion 21 and the separator 13 is laminated. This operation is repeated a predetermined number of times. Then, the communication hole forming member 40 is fitted into the recess 21d of the first sealing portion 21 formed in the uppermost bipolar electrode 14 mounted on the laminating jig, and the negative electrode is terminated on the bipolar electrode 14. The electrodes 18 are laminated. As a result, the unit laminate 30 is formed.

The unit laminate 30 formed in this way has a rectangular first surface 30a intersecting the stacking direction D1, a rectangular second surface 30b opposite to the first surface 30a, and a stacking direction D1. It has four rectangular end faces 30c extending. The first surface 30a includes the surface of the negative electrode terminal electrode 18. The second surface 30b includes the surface of the positive electrode terminal electrode 19. The end face 30c includes a side surface of the first sealing portion 21 extending in the stacking direction D1. That is, the end face 30c is composed of a plurality of laminated first sealing portions 21 (side surfaces). The end surface 30c connects the first surface 30a and the second surface 30b. In the unit laminated body 30, the communication hole forming member 40 is arranged between two electrodes adjacent to each other in the stacking direction D1 among the plurality of electrodes. In the unit laminated body 30, the recesses 21d of the first sealing portions 21 adjacent to each other in the stacking direction D1 may not overlap each other when viewed from the stacking direction D1 and may be provided at positions shifted in the direction D3. The recesses 21d may be provided in each of the first sealing portions 21 so that the plurality of recesses 21d are displaced in a stepped manner.

Subsequently, the step S5 of welding the first sealing portions 21 of the unit laminated body 30 to each other is performed. As shown in FIG. 5, in step S5, the manufacturing apparatus 50 is used. The manufacturing apparatus 50 is a manufacturing apparatus of the power storage module 4, and the first sealing portion 21 is melted by ultrasonic welding, and the first sealing portions 21 are welded to each other, so that the unit is viewed from the stacking direction D1. The positions of the end faces (end faces 30c) of the plurality of first sealing portions 21 of the laminated body 30 are aligned with each other. The manufacturing apparatus 50 includes a restraint portion 51 and a plurality of (four in this embodiment) welding apparatus 52.

The restraint portion 51 sandwiches the unit laminated body 30 in the stacking direction D1 and applies a restraining load along the stacking direction D1 to the unit laminated body 30. The restraint portion 51 includes a clamp member 53 (first clamp member) and a clamp member 54 (second clamp member). The clamp member 53 and the clamp member 54 face each other in the stacking direction D1. The clamp member 53 and the clamp member 54 are made of, for example, a metal such as iron and aluminum. The clamp member 53 is a plate-shaped member provided on the first surface 30a of the unit laminate 30, and presses the first surface 30a. The clamp member 54 is a plate-shaped member provided on the second surface 30b of the unit laminate 30, and presses the second surface 30b. By sandwiching the unit laminated body 30 by the clamp members 53 and 54, a restraining load is applied to the unit laminated body 30 along the stacking direction D1.

Each of the plurality of welding devices 52 is a device that ultrasonically welds the end face 30c of the unit laminate 30. The welding device 52 is provided for each end face 30c. Each welding device 52 includes an oscillator (not shown), an oscillator (not shown), a drive unit 55, and a horn 56. The oscillator generates an electric signal having a predetermined frequency and outputs the electric signal to the oscillator. The oscillator converts the electrical signal generated by the oscillator into mechanical vibration energy (ultrasonic vibration). The drive unit 55 reciprocates the horn 56 with respect to the end surface 30c of the unit laminated body 30 in a direction intersecting (orthogonal) with the end surface 30c. The drive unit 55 is, for example, an air cylinder. The amount of movement of the horn 56 by the drive unit 55 may be regulated by a stopper or the like (not shown).

The horn 56 is a member that receives ultrasonic vibration generated by the vibrator and applies ultrasonic vibration to the end face 30c. Examples of the constituent materials of the horn 56 include titanium, aluminum, duralumin and the like. The horn 56 has a pressing surface 56a that presses the end surface 30c. The pressing surface 56a faces the side surface 53a of the clamp member 53 and the side surface 54a of the clamp member 54. The length of the pressing surface 56a in the stacking direction D1 is longer than the length of the unit laminated body 30 in the state of being sandwiched by the restraint portion 51 in the stacking direction D1.

The pressing surface 56a that presses the end surface 30c on which the communication hole forming member 40 is not provided is a flat surface. A plurality of recesses 56b are provided on the pressing surface 56a that presses the end surface 30c on which the communication hole forming member 40 is provided. The recess 56b is provided corresponding to the communication hole forming member 40. In the end face 30c provided with the communication hole forming member 40, the communication hole forming member 40 protrudes from the end face 30c in the direction D2, so that the communication hole forming member 40 protruding from the end face 30c can be fitted in the recess 56b. It has a (insertable) shape. With the communication hole forming member 40 inserted into the recess 56b, there is a slight gap between the inner surface of the recess 56b and the communication hole forming member 40 so that the first sealing portion 21 in the molten state does not penetrate. It is provided.

In step S5, first, the unit laminated body 30 is sandwiched in the stacking direction D1 by the restraint portion 51. At this time, the peripheral edge portion including the end surface 30c of the unit laminated body 30 is not sandwiched by the restraint portion 51. Then, in a state where the horn 56 receives ultrasonic vibration from the vibrator, the drive unit 55 holds the horn 56 until the distance between the restraint portion 51 (clamp members 53, 54) and the pressing surface 56a becomes a predetermined distance. Move toward the end face 30c. At this time, the communication hole forming member 40 is inserted into the recess 56b of the pressing surface 56a that presses the end surface 30c on which the communication hole forming member 40 is provided. In this way, the end face 30c (first sealing portion 21) is welded by applying ultrasonic vibration to the end face 30c while the pressing surface 56a presses the end face 30c.

By welding the first sealing portions 21 to each other, a communication hole having a shape corresponding to the shape of the communication hole forming member 40 and communicating with the internal space V is formed. Even if there is a gap between the side surface 40b of the communication hole forming member 40 and the inner surface of the recess 21d, the gap is closed by the first sealing portion 21 in the molten state. As described above, since the position of the recess 21d differs depending on the stacking position in the electrode laminated body 11, communication holes are formed at different positions (positions in the direction D3) depending on the stacking position in the electrode laminated body 11.

Subsequently, the step S6 for forming the second sealing portion 22 around the unit laminated body 30 is performed. In step S6, the second sealing portion 22 is formed around the first sealing portion 21 in a state where the communication hole forming member 40 is arranged in the recess 21d. The second sealing portion 22 is formed by, for example, injection molding. Subsequently, the step S7 for removing the communication hole forming member 40 is performed. As a result, the sealing body 12 provided with the communication holes (not shown) is formed. The communication hole is provided corresponding to the recess 21d. Subsequently, the step S8 of injecting the electrolytic solution into the internal space V through the communication hole is performed. After that, the communication hole is closed by a pressure regulating valve (not shown). In this way, the power storage module 4 is manufactured.

Next, the operation and effect of the manufacturing apparatus 50 will be described while comparing with the manufacturing apparatus 150 according to the comparative example. FIG. 6 is a diagram showing a manufacturing apparatus for a power storage module according to a comparative example. The manufacturing apparatus 150 shown in FIG. 6 is mainly different from the manufacturing apparatus 50 in that the hot plate 152 is provided instead of the welding apparatus 52. The hot plate 152 is a high-temperature plate-like member, and the end face 30c is welded by being pressed against the end face 30c of the unit laminate 30.

The hot plate 152 has a pressing surface 152a that presses the end surface 30c. The pressing surface 152a faces the side surface 53a of the clamp member 53 and the side surface 54a of the clamp member 54. The length of the pressing surface 152a in the stacking direction D1 is longer than the length of the unit laminated body 30 in the state of being sandwiched by the restraint portion 51 in the stacking direction D1. The pressing surface 152a that presses the end surface 30c on which the communication hole forming member 40 is provided is provided with a plurality of through holes 152b that penetrate the hot plate 152 in the direction D2. The through hole 152b is provided corresponding to the communication hole forming member 40. The pressing surface 152a has a shape through which a communication hole forming member 40 protruding from the end surface 30c can be inserted.

When the hot plate 152 is pressed against the end face 30c of the unit laminate 30, the end face 30c (first sealing portion 21) is welded. However, if the hot plate 152 is separated from the end face 30c of the unit laminate 30 before the melted first sealing portion 21 is completely solidified, the molten first sealing portion 21 is pulled by the hot plate 152, and the hot plate 152 is pulled. The end face 30c may be rough. When the second sealing portion 22 is formed around the first sealing portion 21 by injection molding while the end face 30c is rough, the rough surface of the rough surface of the resin material of the second sealing portion 22 supplied from the injection molding machine. There is a possibility that the flow is obstructed and the sealing performance of the molded sealing body 12 is deteriorated. On the other hand, in the manufacturing apparatus 150, it takes a very long time to cool the hot plate 152 once heated to a predetermined temperature or lower, so that the hot plate is completely solidified after the melted first sealing portion 21 is completely solidified. If the 152 is separated from the unit laminate 30, the welding time becomes long, which may lead to a decrease in productivity.

Further, since the hot plate 152 has a high temperature, when it comes into contact with the communication hole forming member 40, the heat of the hot plate 152 is transferred to the communication hole forming member 40, and not only the end face 30c but also the communication hole forming in the unit laminate 30 is formed. The portion in contact with the member 40 may be melted, and the sealing performance of the sealing body 12 (first sealing portion 21) may deteriorate. Therefore, in a state where the communication hole forming member 40 is inserted into the through hole 152b, the communication hole forming member 40 comes into contact with the inner surface of the through hole 152b between the inner surface of the through hole 152b and the communication hole forming member 40. There is a sufficient gap so that it does not occur. Therefore, when the pressing surface 152a of the hot plate 152 is pressed against the end surface 30c of the unit laminated body 30 to melt the end surface 30c (first sealing portion 21) of the unit laminated body 30, the first in the molten state is The sealing portion 21 flows into the through hole 152b.

When the first sealing portion 21 in the molten state solidifies in this state, a protruding burr that inserts the through hole 152b is formed. Since the height of burrs and the like cannot be controlled in the manufacturing apparatus 150, burrs having an irregular shape are formed on the end face 30c. When injection molding for forming the second sealing portion 22 is performed on the unit laminate 30 in which such burrs are formed, the flow of the resin material is obstructed by the burrs, and the quality of the second sealing portion 22 deteriorates. There is a risk of Further, since a sufficient gap is provided between the inner surface of the through hole 152b and the communication hole forming member 40, the direction of the communication hole forming member 40 cannot be determined, and the communication hole formed in the first sealing portion 21. There is a risk that the directions will not be aligned at each communication hole.

On the other hand, in the manufacturing apparatus 50 of the power storage module 4, the end face 30c of the unit laminate 30 is welded by ultrasonic welding by applying ultrasonic vibration to the end face 30c of the unit laminate 30 by the horn 56. In ultrasonic welding, the horn 56 is not heated, so it cools as soon as the ultrasonic vibration is stopped. Therefore, as compared with hot plate welding, the time required for the molten end face 30c (first sealing portion 21) to solidify can be shortened, and the welding time can be shortened. Further, the horn 56 has a pressing surface 56a provided with a recess 56b into which a communication hole forming member 40 protruding from the end surface 30c of the unit laminated body 30 can be fitted. In ultrasonic welding, the temperature of the horn 56 is sufficiently lower than the temperature of the hot plate, so that even if the communication hole forming member 40 comes into contact with the recess 56b of the horn 56, the temperature of the communication hole forming member 40 is suppressed from becoming high. Will be done. As a result, the portion of the unit laminate 30 in contact with the communication hole forming member 40 is prevented from melting, and the sealing performance of the first sealing portion 21 can be ensured. Further, the gap provided between the inner surface of the recess 56b and the communication hole forming member 40 can be made narrower than the gap provided between the inner surface of the through hole 152b and the communication hole forming member 40. As a result, the possibility that the melted first sealing portion 21 flows into the recess 56b is reduced, so that the formation of burrs protruding from the end face 30c in the direction D2 is suppressed. As a result, the welding time can be shortened while ensuring the sealing performance of the sealing body 12.

Further, by making the gap provided between the inner surface of the recess 56b and the communication hole forming member 40 narrower than the gap provided between the inner surface of the through hole 152b and the communication hole forming member 40, the communication hole forming member The orientation of 40 can be specified, and the orientation of the communication holes formed in each first sealing portion 21 can be made uniform.

The length of the pressing surface 56a in the stacking direction D1 is longer than the length of the unit laminated body 30 sandwiched by the restraint portion 51 in the stacking direction D1. Further, the peripheral edge portion including the end surface 30c of the unit laminated body 30 is not sandwiched by the restraint portion 51 and protrudes from the restraint portion 51. Therefore, since the pressing surface 56a of the horn 56 can be pressed against the entire end surface 30c of the unit laminate 30, the end surface 30c of the unit laminate 30 can be aligned over the entire surface, and the quality of the end surface 30c of the unit laminate 30 can be aligned. Can be improved.

The drive unit 55 moves the horn 56 toward the end surface 30c until the distance between the restraint unit 51 and the pressing surface 56a in the direction D2 becomes a predetermined distance. That is, when ultrasonic welding is performed, the horn 56 is separated from the restraint portion 51 (clamp members 53, 54), so that it is possible to prevent the generation of foreign matter generated by the rubbing between the horn 56 and the restraint portion 51. Can be done.

Although one embodiment of the present disclosure has been described in detail above, the present disclosure is not limited to the above embodiment.

For example, the constituent material of the communication hole forming member 40 may be a non-metal material such as zirconia and ceramic. When the constituent material of the communication hole forming member 40 is metal, the communication hole forming member 40 and the recess 56b may rub against each other to generate metal foreign matter and adhere to the unit laminate 30. On the other hand, by using a non-metal material as a constituent material of the communication hole forming member 40, it is possible to suppress the generation of metal foreign matter.

The manufacturing apparatus 50 does not have to ultrasonically weld all the end faces 30c. For example, the manufacturing apparatus 50 includes a welding device 52 for welding the end face 30c provided with the communication hole forming member 40, and a hot plate for welding the end face 30c without the communication hole forming member 40. May be good.

In the manufacturing apparatus 50, since the melted first sealing portion 21 hardly flows into the recess 56b, the gap between the pressing surface 56a and the side surface 53a and the pressing surface 56a and the side surface 54a depend on the pressing amount of the pressing surface 56a. The melted first sealing portion 21 may flow out from the gap between the two. The melted first sealing portion 21 solidifies to form burrs B (see (a) in FIG. 8 and (b) in FIG. 8). In ultrasonic welding, the amount of welding can change depending on the welding time, vibration amplitude, pressing force, and the like. For example, the depth at which the end face 30c melts (the length in the direction D2) changes according to the pushing amount of the horn 56. The pushing amount of the horn 56 is a distance from the position of the end face 30c before being pressed by the horn 56 toward the inside of the unit laminate 30 in the normal direction (direction D2) of the end face 30c.

A modified example of the manufacturing apparatus 50 having a configuration for removing the burr B generated by ultrasonic welding will be described with reference to FIGS. 7 and 8 (a) to 8 (c). FIG. 7 is a diagram showing a modified example of the power storage module manufacturing apparatus. 8 (a) to 8 (c) are views for explaining a step of welding end faces using the manufacturing apparatus shown in FIG. 7. The manufacturing apparatus 50 shown in FIGS. 7 and 8 (a) to 8 (c) is shown in FIG. 5 in that the clamp members 53 and 54 are separably configured and further includes a removing portion 57. It is mainly different from the manufacturing apparatus 50.

As shown in FIG. 7, the clamp member 53 includes a main body portion 53b and a tip portion 53c that can be attached to and detached from the main body portion 53b (separable). The tip portion 53c is one end portion in the direction D2 of the clamp member 53, and includes the side surface 53a. The cross section of the tip portion 53c intersecting the direction D3 is trapezoidal. The boundary between the main body portion 53b and the tip portion 53c is inclined so as to be separated from the side surface 53a as the distance from the first surface 30a in the stacking direction D1. The tip portion 53c is removably fixed to the main body portion 53b by, for example, a fixing member such as a bolt.

Similarly, the clamp member 54 includes a main body portion 54b and a tip portion 54c that is detachable (separable) from the main body portion 54b. The tip portion 54c is one end portion in the direction D2 of the clamp member 54 and includes the side surface 54a. The cross section of the tip 54c intersecting the direction D3 is trapezoidal. The boundary between the main body portion 54b and the tip portion 54c is inclined so as to be separated from the side surface 54a as the distance from the second surface 30b in the stacking direction D1. The tip portion 54c is removably fixed to the main body portion 54b by, for example, a fixing member such as a bolt.

The removing unit 57 is a device for removing burrs B generated by ultrasonic welding of the end face 30c. As the removing unit 57, for example, an ultrasonic cutter is used.

As shown in FIG. 8A, the tip portion 53c is attached to the main body portion 53b while the pressing surface 56a of the horn 56 presses the end surface 30c, that is, while ultrasonic welding is performed. The tip portion 54c is attached to the main body portion 54b. The first sealing portion 21 melted by ultrasonic welding flows out from the gap between the pressing surface 56a and the side surface 53a and the gap between the pressing surface 56a and the side surface 54a.

Then, as shown in FIG. 8B, when the ultrasonic vibration is stopped in the welding device 52, the melted first sealing portion 21 is solidified and the horn 56 is separated from the end face 30c. As a result, a flattened end face 30c is obtained. In addition, burrs B are formed on the upper and lower ends of the end face 30c. In order to remove the burr B, the tip portion 53c is removed from the main body portion 53b, and the tip portion 54c is removed from the main body portion 54b.

Then, as shown in FIG. 8C, the burr B is removed (excised) by the removing portion 57. At this time, by removing the tip portion 53c and the tip portion 54c, it is possible to remove only the burr B.

If burrs B are formed on the end face 30c of the unit laminate 30, the burrs B may peel off in the injection molding for forming the second sealing portion 22, and the flow of the molten resin material may be hindered. According to the manufacturing apparatus 50 of the above modification, the burr B generated by ultrasonic welding is removed, so that the quality of the second sealing portion 22 can be ensured.

By removing the tip portion 53c of the clamp member 53 from the main body portion 53b, the possibility that the clamp member 53 is cut together with the burr B can be reduced. This makes it possible to suppress the generation of foreign matter from the clamp member 53. Similarly, by removing the tip portion 54c of the clamp member 54 from the main body portion 54b, the possibility that the clamp member 54 is cut together with the burr B can be reduced. This makes it possible to suppress the generation of foreign matter from the clamp member 54.

As shown in FIGS. 9 and 10, the recess 56b may include a first portion 56c and a second portion 56d. The first portion 56c and the second portion 56d are arranged in the direction D2, and the second portion 56d is farther from the pressing surface 56a than the first portion 56c. The length of the first portion 56c in the stacking direction D1 is longer than the length of the second portion 56d in the stacking direction D1. According to this configuration, the generation of burrs B can be suppressed by the first sealing portion 21 in the molten state flowing into the first portion 56c. The protrusions are formed by solidifying the first sealing portion 21 in the molten state that has flowed into the first portion 56c. However, the length of the first portion 56c in the direction D2 is set so that the protrusions do not obstruct the flow of the resin material in injection molding.

In the example shown in FIG. 9, the first portion 56c has a tapered shape in which the length in the stacking direction D1 becomes shorter as the distance from the pressing surface 56a increases. In other words, the first portion 56c is defined by an inclined surface that inclines downward from the pressing surface 56a toward the second portion 56d and an inclined surface that inclines upward from the pressing surface 56a toward the second portion 56d. It is the part to be done. According to this configuration, the first portion 56c can function as a guide for guiding the communication hole forming member 40 into the recess 56b. Therefore, it is possible to improve the workability of inserting the communication hole forming member 40 into the recess 56b.

In the example shown in FIG. 10, the first portion 56c has a box shape. According to this configuration, as compared with the example shown in FIG. 9, more molten first sealing portions 21 can be filled in the first portion 56c, so that the generation of burrs B can be further suppressed. it can.

The configurations shown in FIGS. 7 and 8 (a) to (c) may also be applied to the modified examples shown in FIGS. 9 and 10.

4 ... Energy storage module, 11 ... Electrode laminate, 12 ... Sealed body, 13 ... Separator, 14 ... Bipolar electrode (electrode), 15 ... Electrode plate, 15c ... Peripheral portion, 18 ... Negative electrode termination electrode (electrode), 19 ... Positive electrode terminal electrode (electrode), 21 ... 1st sealing part, 22 ... 2nd sealing part, 30 ... unit laminate, 30c ... end face, 40 ... communication hole forming member, 50 ... manufacturing equipment, 51 ... restraint part, 52 ... Welding device, 53 ... Clamp member (first clamp member), 53a ... Side surface (face), 53b ... Main body, 53c ... Tip, 54 ... Clamp member (second clamp member), 54a ... Side surface (face) , 54b ... main body, 54c ... tip, 55 ... drive, 56 ... horn, 56a ... pressing surface, 56b ... recess, 56c ... first part, 56d ... second part, 57 ... removal, B ... burr, D1 ... Stacking direction (first direction), D2 ... direction (second direction).

Claims (7)

In the first direction, a unit laminate including an electrode laminate containing a plurality of electrodes laminated in the first direction and a plurality of first sealing portions provided on the peripheral edges of the electrode plates of the plurality of electrodes, respectively. The restraint part to be sandwiched and
A welding device for welding the end faces of the unit laminated body composed of the plurality of laminated first sealing portions by ultrasonic welding.
With
The welding device includes a horn that applies ultrasonic vibration to the end face.
The horn has a pressing surface that presses the end face in a second direction that intersects the first direction.
A communication hole forming member projecting from the end face in the second direction can be fitted to the pressing surface while being arranged between two electrodes adjacent to each other in the first direction among the plurality of electrodes. A power storage module manufacturing device provided with a recess. The device for manufacturing a power storage module according to claim 1, wherein the length of the horn in the first direction is longer than the length of the unit laminate sandwiched by the restraint portion in the first direction. The welding device further includes a drive unit for moving the horn in the second direction.
The power storage module manufacturing apparatus according to claim 2, wherein the driving unit moves the horn toward the end surface until the distance between the restraining portion and the pressing surface in the second direction becomes a predetermined distance. .. The apparatus for manufacturing a power storage module according to any one of claims 1 to 3, further comprising a removing portion for removing burrs generated by ultrasonic welding of the end faces. The restraint portion includes a first clamp member and a second clamp member facing each other in the first direction.
The device for manufacturing a power storage module according to claim 4, wherein the first clamp member includes a main body portion and a tip portion that is detachably provided on the main body portion and has a surface facing the pressing surface. The recess comprises a first portion and a second portion arranged in the second direction.
The second portion is farther from the pressing surface than the first portion.
The device for manufacturing a power storage module according to any one of claims 1 to 5, wherein the length of the first portion in the first direction is longer than the length of the second portion in the first direction. The device for manufacturing a power storage module according to claim 6, wherein the first portion has a tapered shape in which the length in the first direction becomes shorter as the distance from the pressing surface increases.

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