Bipolar type power storage device

Abstract

To provide a bipolar type power storage device capable of suppressing breakage of a liquid injection unit when an electrolyte is supplied from the liquid injection unit to an electrode laminate.SOLUTION: A bipolar type power storage device 1 includes an electrode laminate 100 including a plurality of bipolar electrodes laminated one on top of another, and a frame body holding an edge of the electrode laminate. The frame body includes: a frame body main body 202 having a shape surrounding a periphery of the electrode laminate, and having a liquid injection port 202h for supplying an electrolytic solution to the electrode laminate; a liquid injection portion 210 protruding from an outer surface of the frame body main body and surrounding the liquid injection port; and a reinforcing rib 220 connecting portions separated from each other in an inner peripheral surface of the liquid injection portion or connecting the inner peripheral surface of the liquid injection portion and an inner region 202S1 surrounded by the liquid injection portion in the outer surface of the frame body main body.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a bipolar power storage device. [Background technology]

[0002] Japanese Patent Application Laid-Open No. 2018-73539 discloses an electricity storage device including a stack including bipolar electrodes and a frame for holding the stack, the frame having a liquid injection port for supplying an electrolyte to the stack. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-73539 Summary of the Invention [Problem to be solved by the invention]

[0004] In a bipolar energy storage device such as that described in JP 2018-73539 A, a liquid injection section surrounding a liquid injection port may be provided on a frame. In this case, for example, it is conceivable to supply electrolyte to the electrode stack through the liquid injection port while a jig is pressed against the liquid injection section. In this case, there is a concern that the liquid injection section may be deformed and damaged.

[0005] An object of the present disclosure is to provide a bipolar electricity storage device that can suppress damage to a liquid injection portion when an electrolyte is supplied from the liquid injection portion to an electrode stack. [Means for solving the problem]

[0006] A bipolar energy storage device according to one aspect of the present disclosure includes an electrode stack including a plurality of bipolar electrodes stacked on one another, and a frame that holds an edge portion of the electrode stack, wherein the frame is a frame main body having a shape that surrounds the periphery of the electrode stack and has a liquid injection port for supplying an electrolyte to the electrode stack, a liquid injection portion provided on an outer surface of the frame main body and surrounding the liquid injection port, and reinforcing ribs that connect spaced-apart portions of an inner circumferential surface of the liquid injection portion or connect the inner circumferential surface of the liquid injection portion to the outer surface of the frame main body. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide a bipolar electricity storage device that can suppress damage to the liquid injection part when an electrolyte solution is supplied from the liquid injection part to an electrode stack. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view schematically illustrating a bipolar electricity storage device according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II shown in FIG. [Figure 3] FIG. 2 is a cross-sectional view taken along line III-III shown in FIG. [Figure 4] FIG. 10 is a front view schematically showing a modified example of the reinforcing rib. [Figure 5] FIG. 5 is a cross-sectional view taken along line VV shown in FIG. [Figure 6] FIG. 10 is a cross-sectional view schematically showing a modified example of the reinforcing rib. [Figure 7] FIG. 10 is a front view schematically showing a modified example of the reinforcing rib. [Figure 8] FIG. 8 is a cross-sectional view taken along line VIII-VIII shown in FIG. 7. [Figure 9] FIG. 10 is a front view schematically showing a modified example of the reinforcing rib. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present disclosure will be described with reference to the accompanying drawings, in which the same or corresponding elements are designated by the same reference numerals.

[0010] Fig. 1 is a perspective view schematically showing a bipolar electricity storage device, Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1, and Fig. 3 is a cross-sectional view taken along line III-III in Fig. 1.

[0011] As shown in FIGS. 1 to 3, the bipolar type energy storage device 1 has an electrode stack 100 and a frame 200.

[0012] The electrode stack 100 includes a plurality of bipolar electrodes 110 stacked on top of each other. As shown in Figure 2, the electrode stack 100 has a plurality of bipolar electrodes 110, a positive terminal electrode 120, a negative terminal electrode 130, and a plurality of separators 140.

[0013] Each bipolar electrode 110 has a current collector foil 111, a positive electrode active material layer 112 provided on one surface of the current collector foil 111, and a negative electrode active material layer 113 provided on the other surface of the current collector foil 111. The positive electrode terminal electrode 120 has a current collector plate 121 and the positive electrode active material layer 112. The negative electrode terminal electrode 130 has a current collector plate 131 and the negative electrode active material layer 113. The electrodes 110, 120, and 130 are stacked with a separator 140 interposed between them.

[0014] The frame 200 holds the edge of the electrode stack 100. The frame 200 is made of resin or the like. The frame 200 has a frame main body 202, a liquid injection portion 210, and reinforcing ribs 220.

[0015] The frame body 202 has a shape that surrounds the periphery of the electrode stack 100. In this embodiment, the frame body 202 is formed in a rectangular tubular shape. The frame body 202 seals the edges of the electrode stack 100. The frame body 202 has a liquid injection port 202h for supplying an electrolyte to the electrode stack 100. In this embodiment, the frame body 202 is provided with a plurality of liquid injection ports 202h (three in the example shown in FIG. 1 ) that are aligned in a direction parallel to the stacking direction of the plurality of electrodes (vertical direction) when the frame body 202 is placed on a horizontal surface. Hereinafter, the vertical direction will be defined based on the state in which the frame body 202 is placed on a horizontal surface.

[0016] The liquid injection portion 210 surrounds the liquid injection port 202h. The liquid injection portion 210 surrounds each of the multiple liquid injection ports 202h lined up in the vertical direction. The liquid injection portion 210 is provided on the outer surface 202S of the frame body 202. The liquid injection portion 210 protrudes from the outer surface 202S of the frame body 202. The liquid injection portion 210 is formed by injection molding together with the frame body 202, and is integrated with the frame body 202 by the heat generated during injection molding. The liquid injection portion 210 has an upper wall 211, a lower wall 212, a pair of side walls 213, and a partition wall 214.

[0017] The upper wall 211 is formed above the liquid pouring port 202h. The lower wall 212 is formed below the liquid pouring port 202h. The upper wall 211 and the lower wall 212 face each other in the vertical direction. The upper wall 211 and the lower wall 212 extend in the horizontal direction.

[0018] The pair of side walls 213 are formed on the sides of the liquid pouring port 202h. The pair of side walls 213 connect the upper wall 211 and the lower wall 212. One of the side walls 213 connects one end of the upper wall 211 to one end of the lower wall 212 in the horizontal direction. The other side wall 213 connects the other end of the upper wall 211 to the other end of the lower wall 212 in the horizontal direction.

[0019] Partition wall 214 is provided between upper wall 211 and lower wall 212 and extends horizontally. Partition wall 214 is connected to side wall 213. In the example shown in Fig. 1, liquid injection section 210 has a pair of partition walls 214 that face each other in the up-down direction.

[0020] 3, the upper wall 211, the partition wall 214, and the lower wall 212 may have a shape in which the thickness (vertical dimension) gradually increases toward the frame body 202. Although not shown, each side wall 213 may also have a shape in which the thickness (horizontal dimension) gradually increases toward the frame body 202. In this case, the strength of the liquid injection section 210 is ensured.

[0021] As shown in FIG. 3, the liquid pouring port 202h is formed in an area of ​​the frame body 202 that is surrounded by the walls 211 to 214 of the liquid pouring section 210.

[0022] The reinforcing rib 220 connects portions of the inner circumferential surface of the liquid injection portion 210 that are spaced apart from each other, or connects the inner circumferential surface of the liquid injection portion 210 to an inner region 202S1 of the outer surface 202S of the frame main body 202 that is surrounded by the liquid injection portion 210. In this embodiment, as shown in FIG. 3 , the reinforcing rib 220 connects the upper wall 211 and the lower wall 212. Specifically, the reinforcing rib 220 connects the upper wall 211 and the lower wall 212 via the partition wall 214. In this embodiment, as shown in FIG. 1 , the reinforcing rib 220 also connects a pair of side walls 213 to each other. The reinforcing rib 220 is formed in a flat plate shape that is connected to the inner circumferential surfaces of the upper wall 211, the lower wall 212, and the pair of side walls 213. As shown in FIGS. 1 and 3, the reinforcing rib 220 is provided with a through-hole 220h that allows the electrolyte to flow from the outside of the liquid injection part 210 into the liquid injection port 202h.

[0023] Next, a method for manufacturing the bipolar electricity storage device 1 will be described with reference to Fig. 3. This manufacturing method includes a liquid injection step.

[0024] In the liquid injection step, a jig 300 is used. The jig 300 is made of an elastic material such as rubber. The jig 300 is formed, for example, in the shape of a rectangular parallelepiped. The jig 300 is provided with a supply port 300h for supplying the electrolyte between a pair of walls that face each other in the vertical direction, among the upper wall 211, the lower wall 212, and the partition wall 214. The supply port 300h penetrates the jig 300 in its thickness direction (the left-right direction in FIG. 3).

[0025] In the liquid injection step, the jig 300 is pressed against the liquid injection section 210, and the electrolyte is supplied to the electrode stack 100 through the supply port 300h, the through-hole 220h, and the liquid injection port 202h. The jig 300 is pressed against the liquid injection section 210 by a pressing unit 10 shown in FIG. 3. The pressing plate 12 of the pressing unit 10 is movable along a guide plate 13. The pressing plate 12 is pressed against the jig 300 by a pressing bolt B.

[0026] As described above, the bipolar energy storage device 1 in this embodiment has reinforcing ribs 220 that reinforce the liquid injection portion 210, thereby suppressing deformation of the liquid injection portion 210 and resulting damage to the liquid injection portion 210 when the jig 300 is pressed against the liquid injection portion 210 during the process of supplying electrolyte to the electrode stack 100.

[0027] Furthermore, since the liquid injection part 210 is prevented from falling over when the jig 300 is pressed against the liquid injection part 210, cracking of the area of ​​the frame body 202 around the liquid injection port 202h is prevented.

[0028] In order to prevent the liquid injection portion 210 from collapsing, it is conceivable to increase the thickness of each of the walls 211-214 of the liquid injection portion 210, but doing so would increase the pressing load of the liquid injection portion 210 by the jig 300 (the load required to seal between the jig 300 and the end faces of the walls 211-214). However, in this embodiment, it is possible to prevent the liquid injection portion 210 from collapsing without changing the contact area (area of ​​the sealing portion) between the jig 300 and each of the walls 211-214, and to reinforce the portion of the frame body 202 around the liquid injection port 202h.

[0029] Modifications of the reinforcing rib 220 will be described below.

[0030] <First Modification> As shown in FIGS. 4 and 5 , the reinforcing rib 220 may connect a pair of side walls 213 together. The reinforcing rib 220 may have an upper rib 221 formed above the liquid pouring port 202h and a lower rib 222 formed below the liquid pouring port 202h. The upper rib 221 and the lower rib 222 face each other in the up-down direction. The upper rib 221 and the lower rib 222 are spaced apart from the upper wall 211, the lower wall 212, and the partition wall 214. The upper rib 221 provided between the upper wall 211 and the partition wall 214 may be connected to the upper wall 211, and the lower rib 222 provided between the partition wall 214 and the lower wall 212 may be connected to the lower wall 212.

[0031] As shown in FIG. 5, the amount by which each of the ribs 221, 222 protrudes from the inner region 202S1 of the frame body 202 may be smaller than the amount by which the upper wall 211, the lower wall 212 and the partition wall 214 protrude from the outer surface 202S of the frame body 202.

[0032] 6, the upper rib 221 and the lower rib 222 may have a shape in which the vertical dimension gradually increases toward the inner region 202S1 of the frame body main body 202. In the example shown in Fig. 6, the upper surface of the upper rib 221 is inclined so as to gradually rise upward toward the inner region 202S1 of the frame body main body 202, and the lower surface of the lower rib 222 is inclined so as to gradually rise downward toward the inner region 202S1 of the frame body main body 202.

[0033] In this embodiment, deformation of each side wall 213 during the liquid injection step is suppressed.

[0034] <Second Modification> 7 and 8, the reinforcing rib 220 may connect the inner peripheral surface of the liquid pouring portion 210 and the inner region 202S1 of the frame main body 202. In this example, the reinforcing rib 220 has an upper rib 223 formed above the liquid pouring port 202h and a lower rib 224 formed below the liquid pouring port 202h.

[0035] An upper rib 223 provided between the upper wall 211 and the partition wall 214 connects the inner surface of the upper wall 211 to the inner region 202S1 of the frame body main body 202. An upper rib 223 provided between a pair of partition walls 214 connects the inner surface of the partition wall 214 to the inner region 202S1 of the frame body main body 202. An upper rib 223 provided between the partition wall 214 and the lower wall 212 connects the inner surface of the partition wall 214 to the inner region 202S1 of the frame body main body 202.

[0036] The lower rib 224 provided between the upper wall 211 and the partition wall 214 connects the inner surface of the partition wall 214 to the inner region 202S1 of the frame body main body 202. The lower rib 224 provided between a pair of partition walls 214 connects the inner surface of the partition wall 214 to the inner region 202S1 of the frame body main body 202. The lower rib 224 provided between the partition wall 214 and the lower wall 212 connects the inner surface of the lower wall 212 to the inner region 202S1 of the frame body main body 202.

[0037] As shown in FIG. 8, the upper rib 223 and the lower rib 224 may have a shape in which the dimension in the up-down direction gradually decreases as the distance from the inner region 202S1 of the frame main body 202 increases.

[0038] This embodiment suppresses deformation of the upper wall 211, the lower wall 212, and the partition wall 214 during the liquid injection process. In this example, the upper rib 223 and the lower rib 224 may also connect a pair of side walls 213 to each other.

[0039] <Third Modification> As shown in Fig. 9, the reinforcing rib 220 may have a pair of vertical ribs 225, 226. The pair of vertical ribs 225, 226 are spaced apart from each other in the direction connecting the pair of side walls 213 (the left-right direction in Fig. 9). One vertical rib 225 is formed on one side of the liquid pouring port 202h, and the other vertical rib 226 is formed on the other side of the liquid pouring port 202h. The amount of protrusion of each of the vertical ribs 225, 226 from the inner region 202S1 of the frame body 202 may be smaller than the amount of protrusion of the upper wall 211, the lower wall 212, and the partition wall 214 from the outer surface 202S of the frame body 202.

[0040] The vertical ribs 225, 226 provided between the upper wall 211 and the partition wall 214 connect the upper wall 211 and the partition wall 214. The vertical ribs 225, 226 provided between a pair of partition walls 214 connect the pair of partition walls 214. The vertical ribs 225, 226 provided between the partition wall 214 and the lower wall 212 connect the partition wall 214 and the lower wall 212.

[0041] It will be appreciated by those skilled in the art that the exemplary embodiments and examples described above are examples of the following aspects.

[0042] [Aspect 1] an electrode stack including a plurality of bipolar electrodes stacked on top of one another; a frame body that holds an edge portion of the electrode stack, The frame body is a frame body having a shape that surrounds the periphery of the electrode stack, the frame body having a liquid injection port for supplying an electrolyte to the electrode stack; a liquid injection portion that protrudes from the outer surface of the frame body and surrounds the liquid injection port; a reinforcing rib that connects portions of an inner peripheral surface of the liquid injection portion that are spaced apart from each other, or that connects the inner peripheral surface of the liquid injection portion to an inner region of the outer surface of the frame main body that is surrounded by the liquid injection portion.

[0043] [Aspect 2] The liquid injection section is an upper wall formed above the liquid inlet; a lower wall formed below the liquid inlet; a pair of side walls formed on the sides of the liquid inlet and connecting the upper wall and the lower wall; 2. The bipolar electricity storage device according to aspect 1, wherein the reinforcing rib connects the upper wall and the lower wall.

[0044] In this embodiment, deformation of the upper and lower walls during the liquid injection step is suppressed.

[0045] [Aspect 3] 3. The bipolar electricity storage device according to aspect 2, wherein the reinforcing rib also connects the pair of side walls to each other.

[0046] In this embodiment, deformation of each side wall during the liquid injection step is suppressed.

[0047] [Aspect 4] The liquid injection section is an upper wall formed above the liquid inlet; a lower wall formed below the liquid inlet; a pair of side walls formed on the sides of the liquid inlet and connecting the upper wall and the lower wall; 2. The bipolar electricity storage device according to aspect 1, wherein the reinforcing rib connects the pair of side walls to each other.

[0048] [Aspect 5] The liquid injection section is an upper wall formed above the liquid inlet; a lower wall formed below the liquid inlet; a pair of side walls formed on the sides of the liquid inlet and connecting the upper wall and the lower wall; The reinforcing rib is an upper rib connecting the upper wall and the inner region of the frame body; a lower rib connecting the lower wall and the inner region of the frame body.

[0049] [Aspect 6] The frame body has a plurality of the liquid injection ports formed in a vertical line, Aspect 6. The bipolar electricity storage device according to any one of aspects 1 to 5, wherein the liquid injection section surrounds each of the plurality of liquid injection ports.

[0050] It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present disclosure is defined by the claims rather than the description of the above embodiments, and further includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0051] 1 bipolar type energy storage device, 10 pressing unit, 100 electrode stack, 110 bipolar electrode, 200 frame body, 202 frame body main body, 202h liquid injection port, 202S outer surface, 202S1 inner area, 210 liquid injection portion, 211 upper wall, 212 lower wall, 213 side wall, 214 partition wall, 220 reinforcing rib, 220h through hole, 221 upper rib, 222 lower rib, 223 upper rib, 224 lower rib, 225, 226 vertical ribs, 300 jig, 300h supply port.

Claims

1. an electrode stack including a plurality of bipolar electrodes stacked on top of one another; a frame body that holds an edge portion of the electrode stack, The frame body is a frame body having a shape that surrounds the periphery of the electrode stack, the frame body having a liquid injection port for supplying an electrolyte to the electrode stack; a liquid injection portion that protrudes from the outer surface of the frame body and surrounds the liquid injection port; a reinforcing rib that connects portions of an inner peripheral surface of the liquid injection portion that are spaced apart from each other, or connects the inner peripheral surface of the liquid injection portion to an inner region of the outer surface of the frame main body that is surrounded by the liquid injection portion.

2. The liquid injection section is an upper wall formed above the liquid inlet; a lower wall formed below the liquid inlet; a pair of side walls formed on the sides of the liquid inlet and connecting the upper wall and the lower wall; The bipolar electricity storage device according to claim 1 , wherein the reinforcing rib connects the upper wall and the lower wall.

3. The bipolar electricity storage device according to claim 2 , wherein the reinforcing rib also connects the pair of side walls together.

4. The liquid injection section is an upper wall formed above the liquid inlet; a lower wall formed below the liquid inlet; a pair of side walls formed on the sides of the liquid inlet and connecting the upper wall and the lower wall; The bipolar electricity storage device according to claim 1 , wherein the reinforcing rib connects the pair of side walls together.

5. The liquid injection section is an upper wall formed above the liquid inlet; a lower wall formed below the liquid inlet; a pair of side walls formed on the sides of the liquid inlet and connecting the upper wall and the lower wall; The reinforcing rib is an upper rib connecting the upper wall and the inner region of the frame body; The bipolar electricity storage device according to claim 1 , further comprising: a lower rib connecting the lower wall and the inner region of the frame body.

6. The frame body has a plurality of the liquid injection ports formed in a vertical line, The bipolar electricity storage device according to claim 1 , wherein the liquid injection section surrounds each of the plurality of liquid injection ports.

Images