Power storage device

Abstract

To provide a power storage device capable of suppressing rapid combustion inside a case after gas is discharged through a pressure release valve.SOLUTION: A power storage device 1 includes a plurality of first power storage stacks 110, a plurality of second power storage stacks 120, a case, a first pressure release valve 610, a second pressure release valve 620, a first respiratory membrane 710, and a second respiratory membrane 720. The case has a first accommodation chamber S10, a second accommodation chamber S20, and a partition wall 516 for partition. The first pressure release valve 610 and the first respiratory membrane 710 are provided in the first accommodation chamber S10 .The second pressure release valve 620 and the second respiratory membrane 720 are provided in the second accommodation chamber S20.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to an electricity storage device. [Background technology]

[0002] For example, Japanese Patent Application Laid-Open Publication No. 2023-47012 discloses a battery pack including a plurality of battery cells, a case for accommodating the plurality of battery cells, a pressure release valve provided in the case, and a breather membrane provided in the case. The case has a lower case and an upper cover. The pressure release valve is provided in the upper cover, and the breather membrane is provided in a side wall portion of the lower case. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-47012 Summary of the Invention [Problem to be solved by the invention]

[0004] In the battery pack described in JP 2023-47012 A, when gas is generated in one of the battery cells and the pressure inside the case reaches a reference value, the gas is released through the pressure release valve. At this time, the gas spreads inside the case, so that the gas also comes into contact with the battery cells that are not generating gas.

[0005] An object of the present disclosure is to provide an electricity storage device that can reduce the number of electricity storage cells that come into contact with gas. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, there is provided an energy storage device comprising: a plurality of first energy storage stacks arranged in a line along a first direction; a plurality of second energy storage stacks facing the plurality of first energy storage stacks in a second direction perpendicular to both the first direction and the up-down direction and arranged in a line along the first direction; a case accommodating the plurality of first energy storage stacks and the plurality of second energy storage stacks; a first pressure release valve provided in the case; a second pressure release valve provided in the case; a first breathing membrane provided in the case; and a second breathing membrane provided in the case, wherein the case has a first storage chamber accommodating the plurality of first energy storage stacks, a second storage chamber accommodating the plurality of second energy storage stacks, and a blocking wall blocking the first storage chamber from the second storage chamber, wherein the first pressure release valve and the first breathing membrane are provided in the first storage chamber, and the second pressure release valve and the second breathing membrane are provided in the second storage chamber. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide an electricity storage device that can reduce the number of electricity storage cells that come into contact with gas. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view schematically illustrating a power storage device according to an embodiment of the present disclosure. [Figure 2] 2 is a perspective view schematically illustrating a state in which an upper cover is removed from the electricity storage device illustrated in FIG. 1. FIG. [Figure 3] FIG. 2 is a plan view schematically showing a state in which an upper cover is removed from the power storage device. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 10 is a diagram schematically illustrating a modified example of the power storage device. [Figure 6] FIG. 10 is a diagram schematically illustrating a modified example of the power storage device. 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 that schematically shows an electricity storage device according to an embodiment of the present disclosure. Fig. 2 is a perspective view that schematically shows a state in which an upper cover is removed from the electricity storage device shown in Fig. 1. Fig. 3 is a plan view that schematically shows a state in which the upper cover is removed from the electricity storage device. Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 3. This electricity storage device 1 is mounted, for example, on the bottom of a vehicle.

[0011] As shown in Figures 1 to 4, the energy storage device 1 includes a plurality of first energy storage stacks 110, a plurality of second energy storage stacks 120, a first bus bar 210, a second bus bar 220, a third bus bar 230, a first junction box 310, a second junction box 320, a covering plate 400, a case 500, a first pressure release valve 610, a second pressure release valve 620, a first breathing membrane 710, and a second breathing membrane 720.

[0012] The multiple first power storage stacks 110 are arranged side by side in a first direction. In this embodiment, the multiple first power storage stacks 110 include six first power storage stacks 110. However, the number of first power storage stacks 110 is not limited to six. Each first power storage stack 110 is formed in a rectangular parallelepiped shape that is long in a second direction that is perpendicular to both the first direction and the up-down direction.

[0013] Each first power storage stack 110 includes a plurality of power storage cells 111 (see FIGS. 3 and 4). The plurality of power storage cells 111 are arranged, for example, to be aligned in a first direction. The plurality of power storage cells 111 may also be arranged to be aligned in a second direction. Each power storage cell 111 is formed in a flat rectangular parallelepiped shape. An example of each power storage cell 111 is a lithium ion battery. Each power storage cell 111 may be formed as an all-solid-state battery using a solid electrolyte. Each power storage cell 111 may include a safety valve provided at a position facing the upper cover 520, i.e., on the upper surface of the housing of the power storage cell 111.

[0014] The multiple second power storage stacks 120 are arranged to face the multiple first power storage stacks 110 in the second direction and to be aligned in the first direction. In this embodiment, the multiple second power storage stacks 120 include six second power storage stacks 120. However, the number of second power storage stacks 120 is not limited to six. The configuration of each second power storage stack 120 is the same as the configuration of the first power storage stack 110.

[0015] The first bus bar 210 connects a pair of first power storage stacks 110 adjacent to each other in the first direction. The first bus bar 210 is arranged between the plurality of first power storage stacks 110 and the plurality of second power storage stacks 120.

[0016] The second bus bar 220 connects a pair of second power storage stacks 120 adjacent to each other in the first direction. The second bus bar 220 is arranged between the plurality of first power storage stacks 110 and the plurality of second power storage stacks 120.

[0017] The third busbar 230 connects a first storage stack (hereinafter referred to as "first storage stack 110A") that is arranged on the outermost side in the first direction (e.g., the front side in the longitudinal direction of the vehicle) among the multiple first storage stacks 110, and a second storage stack (hereinafter referred to as "second storage stack 120A") that is arranged on the outermost side in the first direction (e.g., the front side in the longitudinal direction of the vehicle) among the multiple second storage stacks 120.

[0018] The first junction box 310 is disposed at a position facing, in the first direction, a first power storage stack 110 that is disposed at the outermost position in the first direction (for example, on the rear side in the front-to-rear direction of the vehicle) among the multiple first power storage stacks 110. More specifically, the first junction box 310 faces a first power storage stack 110 that is disposed at an end of the multiple first power storage stacks 110 opposite to the side where the first power storage stack 110A connected to the third bus bar 230 is disposed. The first junction box 310 houses a relay, a fuse, and the like. The first junction box 310 has a first connector 312. The first connector 312 protrudes outward in the first direction.

[0019] The second junction box 320 is disposed at a position facing the second power storage stack 120 in the first direction and facing the first junction box 310 at an interval in the second direction. The second junction box 320 houses a relay, a fuse, and the like. As shown in FIG. 3 , in this embodiment, the outer shape of the second junction box 320 is larger than the outer shape of the first junction box 310. The second junction box 320 has a second connector 322. The second connector 322 protrudes outward in the first direction.

[0020] The covering plate 400 (see FIG. 4) covers the first bus bar 210 and the second bus bar 220 from above. The covering plate 400 is disposed between the plurality of first power storage stacks 110 and the plurality of second power storage stacks 120. The covering plate 400 extends along a first direction. The covering plate 400 is formed in a flat plate shape. The covering plate 400 is made of an insulating material. The covering plate 400 is made of, for example, mica, which is a natural inorganic mineral solidified by heat pressing. The covering plate 400 has a function of blocking gas ejected upward from any of the power storage stacks from coming into contact with the bus bars 210, 220, 230. Note that the covering plate 400 is not shown in FIGS. 2 and 3.

[0021] Case 500 houses a plurality of first power storage stacks 110, a plurality of second power storage stacks 120, a first bus bar 210, a second bus bar 220, a third bus bar 230, a first junction box 310, a second junction box 320, and a cover plate 400. Case 500 has a lower case 510 and an upper cover 520.

[0022] The lower case 510 is open upward and has a bottom wall 512, a peripheral wall 514, a blocking wall 516, and a partition 518.

[0023] The bottom wall 512 supports each of the power storage stacks 110 and 120. The bottom wall 512 may be formed in a flat plate shape.

[0024] The peripheral wall 514 stands upright from the peripheral edge of the bottom wall 512. The peripheral wall 514 surrounds the periphery of the plurality of first power storage stacks 110 and the plurality of second power storage stacks 120. The peripheral wall 514 is formed in a substantially rectangular cylindrical shape. The peripheral wall 514 includes a first side wall 514a and a second side wall 514b.

[0025] The first side wall 514a is formed on the side opposite to the side on which the plurality of first power storage stacks 110 and the plurality of second power storage stacks 120 are arranged (the lower side in FIG. 3 ) with respect to the first junction box 310 and the second junction box 320. The first side wall 514a extends along the second direction. The first side wall 514a may be inclined so as to gradually extend outward in the first direction as it extends upward, or may be perpendicular to the bottom wall 512.

[0026] The second side wall 514b faces the first side wall 514a in the first direction. The second side wall 514b faces the first power storage stack 110A and the second power storage stack 120A. The second side wall 514b extends along the second direction.

[0027] The blocking wall 516 separates the plurality of first power storage stacks 110 from the plurality of second power storage stacks 120. The blocking wall 516 has a shape that extends along the first direction. As shown in FIGS. 3 and 4, the blocking wall 516 has a reinforcing portion 516a and a blocking portion 516b. Note that the blocking portion 516b is not shown in FIG. 2.

[0028] The reinforcing portion 516a is connected to the bottom wall 512. The reinforcing portion 516a extends in a first direction. Each end of the reinforcing portion 516a in the first direction is connected to the peripheral wall 514.

[0029] Blocking portion 516b is disposed on reinforcing portion 516a. Each end of blocking portion 516b in the first direction is connected to peripheral wall 514. The dimension of blocking portion 516b in the second direction may be smaller than the dimension of reinforcing portion 516a in the second direction. As shown in FIG. 4, the upper end of blocking portion 516b contacts upper cover 520. For example, first bus bar 210 is disposed on one side of blocking portion 516b in the second direction, and second bus bar 220 is disposed on the other side of blocking portion 516b in the second direction.

[0030] 3, third bus bar 230 penetrates interrupter portion 516b in the second direction. Interrupter portion 516b has a through-hole through which third bus bar 230 is inserted. The gap between third bus bar 230 and the through-hole of interrupter portion 516b is filled with a member made of a heat-resistant material (heat-resistant silicon, etc.).

[0031] The partition 518 separates the first power storage stack 110 from the first junction box 310, and separates the second power storage stack 120 from the second junction box 320. Each end of the partition 518 in the second direction is connected to the peripheral wall 514.

[0032] The upper cover 520 covers the plurality of first power storage stacks 110, the plurality of second power storage stacks 120, the first bus bar 210, the second bus bar 220, the third bus bar 230, the first junction box 310, the second junction box 320, and the covering plate 400. The upper cover 520, together with the lower case 510, accommodates the plurality of first power storage stacks 110, the plurality of second power storage stacks 120, the first bus bar 210, the second bus bar 220, the third bus bar 230, the first junction box 310, the second junction box 320, and the covering plate 400. A peripheral edge portion of the upper cover 520 is fixed to the upper end portion of the peripheral wall 514 with bolts or the like.

[0033] The case 500 has a first storage chamber S10 and a second storage chamber S20.

[0034] The first storage chamber S10 accommodates a plurality of first power storage stacks 110. The first storage chamber S10 is defined by a portion of the bottom wall 512 on one side (the left side in FIG. 3 ) of the blocking wall 516 in the second direction, a portion of the peripheral wall 514 on one side of the blocking wall 516 in the second direction, and a portion of the upper cover 520 on one side of the blocking wall 516 in the second direction.

[0035] The second storage chamber S20 accommodates a plurality of second power storage stacks 120. The second storage chamber S20 is defined by a portion of the bottom wall 512 on the other side (the right side in FIG. 3 ) of the blocking wall 516 in the second direction, a portion of the peripheral wall 514 on the other side of the blocking wall 516 in the second direction, and a portion of the upper cover 520 on the other side of the blocking wall 516 in the second direction.

[0036] The blocking wall 516 blocks the first storage chamber S10 from the second storage chamber S20.

[0037] The first junction box 310 is disposed in the first storage chamber S10. More specifically, the first storage chamber S10 includes a first space S11, and the first junction box 310 is disposed in the first space S11. The first space S11 is defined by a first defining portion 501d. The first defining portion 501d is configured as a part of the first storage chamber S10. The first defining portion 501d defines the first space S11 on one side of the plurality of first power storage stacks 110 in the first direction. In this embodiment, the first defining portion 501d is composed of a portion 512d (see Figure 3) of the bottom wall 512 on one side of the partition portion 518 in the first direction, a portion of the peripheral wall 514 on one side of the partition portion 518 in the first direction, a portion of the blocking wall 516 on one side of the partition portion 518 in the first direction, and a portion 520d (see Figure 1) of the upper cover 520 on one side of the partition portion 518 in the first direction.

[0038] The second junction box 320 is disposed in the second storage chamber S20. More specifically, the second storage chamber S20 includes a second space S21, and the second junction box 320 is disposed in the second space S21. The second space S21 is defined by a second defining portion 502d. The second defining portion 502d is configured as a part of the second storage chamber S20. The second defining portion 502d defines the second space S21 on one side of the plurality of second power storage stacks 120 in the first direction and at a position facing the first space S11 in the second direction with the blocking wall 516 interposed therebetween. In this embodiment, the second defining portion 502d is composed of a portion 512d (see Figure 3) of the bottom wall 512 on one side of the partition portion 518 in the first direction, a portion of the peripheral wall 514 on one side of the partition portion 518 in the first direction, a portion of the blocking wall 516 on one side of the partition portion 518 in the first direction, and a portion 520d (see Figure 1) of the upper cover 520 on one side of the partition portion 518 in the first direction.

[0039] The first pressure release valve 610 is provided in the first storage chamber S10 of the case 500. The first pressure release valve 610 releases the pressure in the first storage chamber S11. The first pressure release valve 610 opens when the pressure in the first storage chamber S11 reaches or exceeds a reference value. The first pressure release valve 610 is configured as a check valve.

[0040] In this embodiment, the first pressure release valve 610 is provided in the first defining portion 501d. More specifically, as shown in Figures 1 and 3, the first pressure release valve 610 is provided in a portion of the upper cover 520 above the first space S11. Note that in Figure 3, the first pressure release valve 610 is indicated by a two-dot chain line.

[0041] The second pressure release valve 620 is provided in the second storage chamber S20 of the case 500. The second pressure release valve 620 has the same configuration as the first pressure release valve 610.

[0042] In this embodiment, the second pressure release valve 620 is provided in the second defining portion 502d. More specifically, as shown in Figures 1 and 3, the second pressure release valve 620 is provided in a portion of the upper cover 520 above the second space S21. Note that in Figure 3, the second pressure release valve 620 is indicated by a two-dot chain line.

[0043] The first breathing membrane 710 is provided in the first storage chamber S11 of the case 500. The first breathing membrane 710 adjusts the pressure inside the first storage chamber S11 by allowing gas to pass between the inside of the first storage chamber S11 and the outside of the case 500.

[0044] In the present embodiment, the first breathing membrane 710 is provided on the first defining portion 501d. The first breathing membrane 710 is preferably arranged on the opposite side of the first pressure release valve 610 from the side on which the first power storage stack 110 is arranged. In the present embodiment, the first breathing membrane 710 is provided on the first side wall 514a. Specifically, a through-hole is provided in the first side wall 514a, and the first breathing membrane 710 is attached to the outer surface of the first side wall 514a so as to cover the through-hole.

[0045] The second breathing membrane 720 is provided in the second storage chamber S21 of the case 500. The configuration of the second breathing membrane 720 is the same as the configuration of the first breathing membrane 710.

[0046] In this embodiment, the second breathing membrane 720 is provided on the second defining portion 502d. The second breathing membrane 720 is preferably arranged on the opposite side of the second pressure release valve 620 from the side on which the second power storage stack 120 is arranged. In this embodiment, the second breathing membrane 720 is provided on the first side wall 514a.

[0047] As described above, in the energy storage device 1 of the present embodiment, the pressure release valves 610, 620 and the breathing membranes 710, 720 are provided in the storage chambers S10, S20 that are isolated from each other by the blocking wall 516, so that, for example, when gas is discharged from the first energy storage stack 110 arranged in the first storage chamber S10, the gas is discharged to the outside of the case 500 through the first pressure release valve 610. This prevents the gas discharged from the first energy storage stack 110 from coming into contact with the second energy storage stack 120 arranged in the second storage chamber S20.

[0048] Modifications of the above embodiment will now be described.

[0049] <First Modification> 5, the first pressure release valve 610 and the first breathing membrane 710 may be provided in a portion of the first storage chamber S10 on the opposite side (upper side in FIG. 5) from the side where the first junction box 310 is disposed in the first direction. Similarly, the second pressure release valve 620 and the second breathing membrane 720 may be provided in a portion of the second storage chamber S20 on the opposite side from the side where the second junction box 320 is disposed in the first direction.

[0050] The "opposite side portion" of the first storage chamber S10 includes a portion of the bottom wall 512 that overlaps vertically with the first storage stack 110A that is positioned outermost in the first direction, a portion of the peripheral wall 514 that surrounds the first storage stack 110A, and a portion of the upper cover 520 that overlaps vertically with the first storage stack 110A.

[0051] The "opposite side portion" of the second storage chamber S20 includes a portion of the bottom wall 512 that overlaps vertically with the second storage stack 120A that is positioned outermost in the first direction, a portion of the peripheral wall 514 that surrounds the second storage stack 120A, and a portion of the upper cover 520 that overlaps vertically with the second storage stack 120A.

[0052] 5, the first pressure release valve 610 and the second pressure release valve 620 are provided on the upper cover 520. The first breathing membrane 710 and the second breathing membrane 720 are provided on the second side wall 514b of the peripheral wall 514.

[0053] In this embodiment, the junction boxes 310, 320 are positioned away from the pressure release valves 610, 620 and the breathing membranes 710, 720, thereby preventing the junction boxes 310, 320 from being affected by the heat of the gas discharged from the power storage stack.

[0054] <Second Modification> 6, the breathing membranes 710, 720 may be provided at portions of the peripheral wall 514 that face each other in the second direction. The same applies to the pressure release valves 610, 620. However, in the example shown in FIG. 6, the pressure release valves 610, 620 are provided on the upper cover 520.

[0055] It will be appreciated by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0056] [Aspect 1] a plurality of first power storage stacks arranged to be aligned along a first direction; a plurality of second power storage stacks that face the plurality of first power storage stacks in a second direction that is orthogonal to both the first direction and the up-and-down direction and are arranged side by side along the first direction; a case that accommodates the plurality of first power storage stacks and the plurality of second power storage stacks; a first pressure release valve provided in the case; a second pressure release valve provided in the case; a first breathing membrane provided on the case; a second breathing membrane provided on the case; The case is a first storage chamber that stores the plurality of first power storage stacks; a second storage chamber that accommodates the plurality of second power storage stacks; a blocking wall that blocks the first storage chamber from the second storage chamber, the first pressure release valve and the first breathing membrane are provided in the first storage chamber, The second pressure release valve and the second breathing membrane are provided in the second storage chamber.

[0057] In this energy storage device, each storage chamber, which is separated from the others by a blocking wall, is provided with a pressure release valve and a breathing membrane, so that even if gas is discharged from the energy storage stack in one of the storage chambers, the gas is prevented from coming into contact with the energy storage stacks stored in other storage chambers.

[0058] [Aspect 2] a first junction box disposed in the first chamber; a second junction box disposed in the second chamber, the first accommodation chamber has a first defining portion that defines a first space on one side of the plurality of first power storage stacks in the first direction, the second accommodation chamber has a second defining portion that defines a second space at a position on one side of the plurality of second power storage stacks in the first direction and facing the first space in the second direction with the blocking wall interposed therebetween; the first junction box is disposed in the first space, the second junction box is disposed in the second space, the first pressure release valve and the first breathing membrane are provided in the first defining portion, 2. The power storage device according to aspect 1, wherein the second pressure release valve and the second breathing membrane are provided in the second defining portion.

[0059] In this embodiment, the space near the junction box in each space is effectively utilized, making it possible to avoid the case becoming larger due to the installation of each pressure release valve and each breathing membrane.

[0060] [Aspect 3] a first junction box disposed in the first accommodation chamber at a position facing the plurality of first power storage stacks in the first direction; a second junction box disposed in the second accommodation chamber at a position facing the plurality of second power storage stacks in the first direction and facing the first junction box in the second direction across the blocking wall, the first pressure release valve and the first breathing membrane are provided in a portion of the first accommodation chamber opposite to a side on which the first junction box is disposed in the first direction, The energy storage device of aspect 1, wherein the second pressure release valve and the second breathing membrane are provided in a portion of the second storage chamber opposite the side on which the second junction box is located in the first direction.

[0061] In this embodiment, each junction box is positioned away from each pressure release valve and each breathing membrane, thereby preventing each junction box from being affected by the heat of the gas discharged from the energy storage stack.

[0062] 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]

[0063] 1 Energy storage device, 110 First energy storage stack, 111 Energy storage cell, 120 Second energy storage stack, 210 First bus bar, 220 Second bus bar, 230 Third bus bar, 310 First junction box, 312 First connector, 320 Second junction box, 322 Second connector, 400 Covering plate, 500 Case, 501d First defining portion, 502d Second defining portion, 510 Lower case, 512 Bottom wall, 514 Peripheral wall, 514a First side wall, 514b Second side wall, 516 Baffle wall, 520 Upper cover, 522 Top wall, 610 First pressure release valve, 620 Second pressure release valve, 710 First breathing membrane, 720 Second breathing membrane, S10 First storage chamber, S11 First space, S20 Second storage chamber, S21 Second space.

Claims

1. a plurality of first power storage stacks arranged to be aligned along a first direction; a plurality of second power storage stacks that face the plurality of first power storage stacks in a second direction that is orthogonal to both the first direction and the up-and-down direction and are arranged side by side along the first direction; a case that accommodates the plurality of first power storage stacks and the plurality of second power storage stacks; a first pressure release valve provided in the case; a second pressure release valve provided in the case; a first breathing membrane provided on the case; a second breathing membrane provided on the case; The case is a first storage chamber that accommodates the plurality of first power storage stacks; a second storage chamber that accommodates the plurality of second power storage stacks; a blocking wall that blocks the first storage chamber from the second storage chamber, the first pressure release valve and the first breathing membrane are provided in the first storage chamber, The second pressure release valve and the second breathing membrane are provided in the second storage chamber.

2. a first junction box disposed in the first chamber; a second junction box disposed in the second chamber, the first accommodation chamber has a first defining portion that defines a first space on one side of the plurality of first power storage stacks in the first direction, the second storage chamber has a second defining portion that defines a second space at a position on one side of the plurality of second power storage stacks in the first direction and facing the first space in the second direction with the blocking wall interposed therebetween; the first junction box is disposed in the first space, the second junction box is disposed in the second space, the first pressure release valve and the first breathing membrane are provided in the first defining portion, The power storage device according to claim 1 , wherein the second pressure release valve and the second breathing membrane are provided in the second defining portion.

3. a first junction box disposed in the first chamber at a position facing the plurality of first power storage stacks in the first direction; a second junction box disposed in the second accommodation chamber at a position facing the second plurality of second power storage stacks in the first direction and facing the first junction box in the second direction across the blocking wall, the first pressure release valve and the first breathing membrane are provided in a portion of the first accommodation chamber opposite to a side on which the first junction box is disposed in the first direction, 2. The power storage device according to claim 1, wherein the second pressure release valve and the second breathing membrane are provided in a portion of the second storage chamber opposite to a side on which the second junction box is disposed in the first direction.

Images