Power storage device

Abstract

To provide a power storage device capable of reducing a flow rate of gas discharged from a case.SOLUTION: A power storage device 1 includes a plurality of first power storage stacks 110, a plurality of second power storage stacks 120, a first junction box 310, a second junction box 320, a case, and a pressure relief valve 600. The case includes an upper cover. The pressure relief valve 600 is provided at a location above an inter-box space S2 between the first junction box 310 and the second junction box 320 within the upper cover.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] For example, JP 2022-516519 A discloses a power battery pack including a plurality of cells, a battery tray for accommodating the cells, and a cover plate connected to the battery tray. A battery pack explosion-proof valve is attached to the side wall of the battery tray and is attached to an exhaust hole. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2022-516519 Summary of the Invention [Problem to be solved by the invention]

[0004] In the power battery pack described in JP 2022-516519 A, gas discharged from the cells flows toward the side wall and is discharged through the battery pack explosion-proof valve provided on the side wall. It is desirable that the outflow rate of this gas is low.

[0005] An object of the present disclosure is to provide an electricity storage device that can reduce the flow rate of gas discharged from the case. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, there is provided an energy storage device including a plurality of first energy storage stacks arranged side by side 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 a vertical direction and arranged side by side along the first direction, a first junction box arranged at a position facing the first direction to the first energy storage stack that is arranged outermost in the first direction among the plurality of first energy storage stacks, a second junction box arranged at a position facing the second energy storage stack in the first direction and facing the first junction box in the second direction, and The battery pack includes a case that houses a plurality of first storage stacks, the plurality of second storage stacks, the first junction box, and the second junction box, and a pressure release valve that is provided in the case and releases pressure within the case, wherein the case includes an upper cover that covers the plurality of first storage stacks, the plurality of second storage stacks, the first junction box, and the second junction box, and an inter-box space is formed between the first junction box and the second junction box, and the pressure release valve is provided in a portion of the upper cover above the inter-box space. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide an electricity storage device that is capable of reducing the flow rate of gas discharged from the case. [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 and a cover plate are removed from the electricity storage device illustrated in FIG. 1. FIG. [Figure 3] FIG. 2 is a cross-sectional view taken along line III-III in FIG. [Figure 4]FIG. 2 is a plan view schematically showing a state in which an upper cover and a cover plate are removed from the electricity storage device. [Figure 5] FIG. 5 is a partially enlarged view of FIG. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. [Figure 7] FIG. 10 is a diagram schematically illustrating a modified example of the power storage device. [Figure 8] FIG. 10 is a diagram schematically illustrating a modified example of the power storage device. [Figure 9] FIG. 10 is a diagram schematically illustrating a modified example of the power storage device. [Figure 10] 10A and 10B are diagrams schematically showing modified examples of the upper cover. [Figure 11] FIG. 11 is a cross-sectional view taken along line XI-XI in FIG. [Figure 12] 10A and 10B are diagrams schematically showing modified examples of the upper cover. 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 and a covering plate are removed from the electricity storage device shown in Fig. 1. Fig. 3 is a cross-sectional view taken along line III-III in Fig. 1. Fig. 4 is a plan view that schematically shows a state in which an upper cover and a covering plate are removed from the electricity storage device. Fig. 5 is a partially enlarged view of Fig. 4. Fig. 6 is a cross-sectional view taken along line VI-VI in Fig. 4. This electricity storage device 1 is mounted, for example, on the bottom of a vehicle.

[0011] As shown in Figures 1 to 6, 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 first junction box 310, a second junction box 320, a covering plate 400, a case 500, a pressure release valve 600, and a breathing membrane 700.

[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 FIG. 3). 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. As shown in FIG. 6, each power storage cell 111 includes a safety valve 111a 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 routed in a routing space S1 (see FIG. 3 ) 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 routed in the routing space S1.

[0017] The first junction box 310 is disposed at a position facing, in the first direction, a first power storage stack 110 that is disposed outermost in the first direction among the multiple first power storage stacks 110 (for example, on the front side in the front-to-rear direction of the vehicle). 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.

[0018] 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. That is, an inter-box space S2 (see FIG. 4 ) is formed between the first junction box 310 and the second junction box 320. The inter-box space S2 is a space through which gas discharged from either of the power storage stacks 110, 120 can pass. The second junction box 320 accommodates a relay, a fuse, and the like. As shown in FIG. 2 , 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.

[0019] The first junction box 310 has a first protrusion 314 that protrudes toward the second junction box 320. The second junction box 320 has a second protrusion 324 that protrudes toward the first junction box 310. Each of the protrusions 314, 324 reduces the flow path area of ​​the inter-box space S2.

[0020] As shown in FIG. 4 , the covering plate 400 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. Note that the covering plate 400 is not shown in FIGS. 2 , 4 , and 5 .

[0021] The case 500 accommodates 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 first junction box 310, a second junction box 320, and a cover plate 400. The 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, and a partition 516.

[0023] The bottom wall 512 supports each of the power storage stacks 110, 120.

[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.

[0025] The peripheral wall 514 includes a side wall 514a formed on the side opposite (the left side in FIG. 4 ) to the side on which the plurality of first power storage stacks 110 and the plurality of second power storage stacks 120 are arranged, with the first junction box 310 and the second junction box 320 as references. The side wall 514a extends along the second direction.

[0026] The partition 516 separates the plurality of first power storage stacks 110 from the plurality of second power storage stacks 120. The partition 516 has a shape that extends along the first direction. The height of the partition 516 is lower than the height of the peripheral wall 514. As shown in FIG. 3 , a wiring space S1 is formed between the partition 516 and the cover plate 400.

[0027] Upper cover 520, together with lower case 510, accommodates a plurality of first power storage stacks 110, a plurality of second power storage stacks 120, first bus bar 210, second bus bar 220, first junction box 310, second junction box 320, and cover plate 400. The peripheral edge of upper cover 520 is fixed to the upper end of peripheral wall 514 with bolts or the like.

[0028] 6, a shielding portion 525 is provided on the inner surface of the upper cover 520. The shielding portion 525 is provided on a path connecting the safety valve 111a and the pressure release valve 600. In this embodiment, the shielding portion 525 is provided in a portion of the inner surface of the upper cover 520 in front of each of the power storage stacks 110, 120. The shielding portion 525 is provided above the inter-box space S2. The shielding portion 525 has a shape that extends downward from the upper cover 520.

[0029] 6, the shielding portion 525 may have a shielding plate 525a extending downward from the inner surface of the upper cover 520. The lower end of the shielding plate 525a is preferably located lower than the covering plate 400.

[0030] The pressure release valve 600 is provided in the case 500. The pressure release valve 600 releases pressure inside the case 500. The pressure release valve 600 opens when the pressure inside the case 500 reaches or exceeds a reference value. The pressure release valve 600 is configured as a check valve. As shown in FIGS. 4 to 6 , the pressure release valve 600 is provided in a portion of the upper cover 520 between the plurality of first power storage stacks 110 and the plurality of second power storage stacks 120, and outside the plurality of first power storage stacks 110 and the plurality of second power storage stacks 120 in the first direction. In this embodiment, the pressure release valve 600 is provided in a portion of the upper cover 520 above the inter-box space S2.

[0031] The breathing membrane 700 is provided on the case 500. The breathing membrane 700 adjusts the pressure inside the case 500 by allowing gas to pass between the inside and outside of the case 500. The breathing membrane 700 is arranged on the opposite side of the pressure release valve 600 from the side on which the power storage stacks 110, 120 are arranged. In this embodiment, the breathing membrane 700 is provided on the side wall 514a. Specifically, a through-hole is provided in the side wall 514a, and the breathing membrane 700 is attached to the outer surface of the side wall 514a so as to cover the through-hole.

[0032] 4 and 5, the breathing membrane 700 is provided on the outer surface of a facing region R of the side wall 514a that faces the first junction box 310 and the second junction box 320. As shown in Fig. 4, the facing region R extends from a region a1 that faces the outer end of the first junction box 310 in the second direction in the first direction to a region a2 that faces the outer end of the second junction box 320 in the second direction in the first direction. Note that in Figs. 4 and 5, the facing region R is indicated by dots.

[0033] The facing region R has a first facing portion R1, a second facing portion R2, and an intermediate portion R3. The first facing portion R1 faces the first junction box 310. The first facing portion R1 is an area that overlaps with the first junction box 310 in the first direction. The second facing portion R2 faces the second junction box 320. The second facing portion R2 is an area that overlaps with the second junction box 320 in the first direction. In this embodiment, the area of ​​the second facing portion R2 is larger than the area of ​​the first facing portion R1. The intermediate portion R3 faces the inter-box space S2. The intermediate portion R3 is located between the first facing portion R1 and the second facing portion R2. In this embodiment, the respiratory membrane 700 is provided in the intermediate portion R3.

[0034] 5, the length D2 of the breathing membrane 700 in the second direction is greater than the length D1 in the second direction between the first junction box 310 and the second junction box 320. In this embodiment, the length D1 is the length between each of the protrusions 314, 324.

[0035] As described above, in the energy storage device 1 of this embodiment, when gas is discharged from either of the energy storage stacks 110, 120, the gas mainly flows toward the inter-box space S2 between the first junction box 310 and the second junction box 320, where it changes direction upward and flows toward the pressure release valve 600, thereby reducing the flow rate of the gas discharged from the case 500.

[0036] In the above embodiment, the respiratory membrane 700 is provided in the opposing region R on the side wall 514a of the lower case 510, in other words, downstream of each junction box 310, 320 in the flow direction of gas discharged from either of the power storage stacks 110, 120. Therefore, the gas discharged from either of the power storage stacks 110, 120 collides with each of the junction boxes 310, 320 before reaching the respiratory membrane 700. Furthermore, the inter-box space S2 serves as a buffer region, which prevents the exhaust gas from reaching the respiratory membrane 700 and thereby prevents damage to the respiratory membrane 700.

[0037] Furthermore, if gas is generated from either of the storage stacks 110, 120 and air flows into the case 500 through the breathing membrane 700, the air comes into contact with each of the junction boxes 310, 320, thereby preventing the air that flows into the case 500 from reaching the storage stacks 110, 120 and the resulting generation of a blast from the safety valve 111a.

[0038] Modifications of the above embodiment will now be described.

[0039] <First Modification> As shown in FIG. 7, when the outer shape of the second junction box 320 is larger than the outer shape of the first junction box 310, the breathing membrane 700 may be provided on the second opposing portion R2.

[0040] <Second Modification> 8, the breathing membrane 700 may have a first breathing portion 710 provided in the first opposing portion R1 and a second breathing portion 720 provided in the second opposing portion R2. The configurations of the breathing portions 710 and 720 are the same as those of the breathing membrane 700 in the above embodiment.

[0041] <Third Modification> 9 , the lower case 510 may have an opposite-side space S3 located between the plurality of first power storage stacks 110 and the plurality of second power storage stacks 120, and on the opposite side to the side on which the inter-box space S2 is located with respect to the plurality of first power storage stacks 110 and the plurality of second power storage stacks 120. In this case, the pressure release valve 600 may be provided in a portion of the upper cover 520 above the opposite-side space S3.

[0042] In this case, the breathing membrane 700 is provided on a side wall 514b formed on the side of the peripheral wall 514 opposite the side on which the power storage stacks 110, 120 are arranged, with the pressure release valve 600 as the reference.

[0043] <Fourth Modification> As shown in FIGS. 10 and 11, the upper cover 520 may have a first base portion 521, a second base portion 522, and an intermediate portion 523.

[0044] The first base portion 521 covers the multiple first power storage stacks 110. The second base portion 522 covers the multiple second power storage stacks 120. Each of the base portions 521, 522 extends along the first direction. Each of the base portions 521, 522 may be formed in a flat plate shape.

[0045] The intermediate portion 523 is provided between the first base portion 521 and the second base portion 522. The intermediate portion 523 extends along the first direction. The intermediate portion 523 is located above the inter-box space S2. The intermediate portion 523 protrudes from each of the base portions 521, 522. As a result, a space S4 is formed between the intermediate portion 523 and the covering plate 400.

[0046] In this example, the pressure relief valve 600 is provided in the middle section 523 .

[0047] <Fifth Modification> 12, the intermediate portion 523 of the upper cover 520 may have a bending rigidity lower than that of each of the base portions 521, 522. In this example, a rib extending along the second direction is formed on each of the base portions 521, 522. However, the thickness of each of the base portions 521, 522 may be greater than the thickness of the intermediate portion 523. Alternatively, the intermediate portion 523 may be formed with a plurality of grooves (deformation promoting portions) that are spaced apart from each other in the second direction and each extend along the first direction.

[0048] In this embodiment, the middle portion 523 deforms so as to bulge upward relative to the base portions 521 and 522 when the internal pressure of the case 500 increases, so that an exhaust flow path is formed between the upper cover 520 and the covering plate 400 .

[0049] It will be appreciated by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0050] [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 first junction box arranged in a position facing, in the first direction, the first power storage stack that is arranged outermost in the first direction among the plurality of first power storage stacks; a second junction box disposed at a position facing the second power storage stack in the first direction and facing the first junction box in the second direction; a case that accommodates the plurality of first power storage stacks, the plurality of second power storage stacks, the first junction box, and the second junction box; a pressure relief valve provided in the case for releasing pressure inside the case; the case includes an upper cover that covers the plurality of first power storage stacks, the plurality of second power storage stacks, the first junction box, and the second junction box; an inter-box space is formed between the first junction box and the second junction box, The pressure release valve is provided in a portion of the upper cover above the inter-box space.

[0051] In this energy storage device, when gas is discharged from any of the energy storage stacks, the gas mainly flows toward the inter-box space between the first junction box and the second junction box, where it changes direction upward and flows toward the pressure release valve, thereby reducing the flow rate of the gas discharged from the case.

[0052] [Aspect 2] The upper cover further includes a shielding portion provided on an inner surface thereof, each of the first power storage stack and the second power storage stack includes a plurality of power storage cells; each of the storage cells includes a safety valve provided at a position facing the upper cover; 2. The power storage device according to claim 1, wherein the shielding portion is provided on a path connecting the safety valve and the pressure release valve and has a shape that extends downward from the upper cover.

[0053] In this embodiment, the gas and blast discharged from the safety valve are blocked by the shielding portion before they reach the pressure release valve, thereby further reducing the flow rate of the gas discharged from the pressure release valve and suppressing the blast from reaching the pressure release valve.

[0054] [Aspect 3] a breathing membrane provided in the case for adjusting the pressure inside the case by allowing gas to pass between the inside of the case and the outside of the case; the case has a sidewall formed on a side opposite to a side on which the first and second power storage stacks are arranged, with respect to the first junction box and the second junction box; 3. The power storage device according to aspect 1 or 2, wherein the breathing membrane is provided on the side wall.

[0055] In this embodiment, two junction boxes are placed between the breathing membrane and each storage stack, thereby preventing air that flows into the case through the breathing membrane from reaching the storage stack and the resulting generation of blast.

[0056] [Aspect 4] a first bus bar that connects a pair of the first power storage stacks adjacent to each other in the first direction and is routed in a routing space between the plurality of first power storage stacks and the plurality of second power storage stacks; a second bus bar that connects a pair of the second power storage stacks adjacent to each other in the first direction and is routed in the routing space; The energy storage device of any one of aspects 1 to 3, further comprising: a cover plate disposed between the plurality of first energy storage stacks and the plurality of second energy storage stacks, the cover plate covering the first bus bar and the second bus bar from above.

[0057] In this embodiment, the space between each storage stack is utilized as routing space for routing each bus bar, and furthermore, the covering plate effectively prevents gas discharged from the storage stack from coming into contact with each bus bar.

[0058] [Aspect 5] The upper cover is a first base portion covering the plurality of first power storage stacks; a second base portion covering the plurality of second power storage stacks; an intermediate portion provided between the first base portion and the second base portion and extending along the first direction; 5. The power storage device according to any one of aspects 1 to 4, wherein the intermediate portion is located above the inter-box space and protrudes from the first base portion and the second base portion.

[0059] In this aspect, an exhaust flow path is formed between the intermediate portion and each power storage stack, so that gas exhausted from the power storage stack is effectively guided toward the pressure release valve.

[0060] [Aspect 6] The upper cover is a first base portion covering the plurality of first power storage stacks; a second base portion covering the plurality of second power storage stacks; an intermediate portion provided between the first base portion and the second base portion and extending along the first direction; The energy storage device according to any one of aspects 1 to 4, wherein the intermediate portion is located above the inter-box space and has a bending rigidity lower than that of the first base portion and that of the second base portion.

[0061] In this embodiment, when the internal pressure of the case rises, the intermediate portion deforms relative to each base portion in a direction away from each storage stack, thereby forming an exhaust flow path between the intermediate portion and each storage stack, and therefore the gas discharged from the storage stack is effectively guided toward the pressure release valve.

[0062] [Aspect 7] 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 first junction box arranged in a position facing, in the first direction, the first power storage stack that is arranged outermost in the first direction among the plurality of first power storage stacks; a second junction box arranged at a position facing the second power storage stack in the first direction and facing the first junction box at an interval in the second direction; a case that accommodates the plurality of first power storage stacks, the plurality of second power storage stacks, the first junction box, and the second junction box; a pressure relief valve provided in the case for releasing pressure inside the case; a breathing membrane provided in the case, which adjusts the pressure inside the case by allowing gas to pass between the inside of the case and the outside of the case; the case includes an upper cover that covers the plurality of first power storage stacks, the plurality of second power storage stacks, the first junction box, and the second junction box; the pressure release valve is provided in a portion of the upper cover between the plurality of first power storage stacks and the plurality of second power storage stacks and above a space outside the plurality of first power storage stacks and the plurality of second power storage stacks in the first direction, the case has a sidewall formed on a side opposite to a side on which the first and second power storage stacks are arranged with respect to the pressure release valve, The breathing membrane is provided on the side wall.

[0063] In this energy storage device, when gas is discharged from any of the energy storage stacks, the gas heads toward the space on the opposite side of the junction boxes, where it changes direction upward toward the pressure release valve, thereby preventing the exhaust gas from reaching the junction boxes and reducing the flow rate of the gas discharged from the case.

[0064] [Aspect 8] 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 first junction box arranged in a position facing, in the first direction, the first power storage stack that is arranged outermost in the first direction among the plurality of first power storage stacks; a second junction box arranged at a position facing the second power storage stack in the first direction and facing the first junction box at an interval in the second direction; a case that accommodates the plurality of first power storage stacks, the plurality of second power storage stacks, the first junction box, and the second junction box; a breathing membrane provided in the case, which adjusts the pressure inside the case by allowing gas to pass between the inside of the case and the outside of the case; the case has a sidewall formed on a side opposite to a side on which the first power storage stack and the second power storage stack are disposed, with respect to the first junction box and the second junction box; the side wall has an opposing region opposing the first junction box and the second junction box, the facing region extends from a portion facing an outer end of the first junction box in the second direction to a portion facing an outer end of the second junction box in the second direction, The breathing membrane is provided in the opposing region.

[0065] In this energy storage device, the breathing membranes are provided in opposing regions on the side walls of the case. In other words, the breathing membranes are located downstream of the junction boxes in the flow direction of gas discharged from any of the energy storage stacks. Therefore, the gas discharged from the energy storage stacks collides with the junction boxes before reaching the breathing membrane. Furthermore, the spaces between the junction boxes act as buffer regions, preventing exhaust gas from reaching the breathing membrane and resulting damage to the breathing membrane.

[0066] [Aspect 9] the facing region includes an intermediate portion facing an inter-box space between the first junction box and the second junction box, 9. The power storage device according to aspect 8, wherein the breathing membrane is provided in the middle portion.

[0067] [Aspect 10] The facing region is a first opposing portion opposing the first junction box; a second opposing portion opposing the second junction box, 9. The power storage device according to aspect 8, wherein the breathing film is provided in the first opposing portion or the second opposing portion.

[0068] In this embodiment, the breathing film is located downstream of one of the junction boxes, so that the exhaust gas is more reliably prevented from reaching the breathing film.

[0069] [Aspect 11] The outer shape of the second junction box is larger than the outer shape of the first junction box, 11. The power storage device according to aspect 10, wherein the breathing film is provided on the second opposing portion.

[0070] [Aspect 12] The facing region is a first opposing portion opposing the first junction box; a second opposing portion opposing the second junction box, The respiratory membrane is a first breathing section provided in the first opposing section; 9. The power storage device according to aspect 8, further comprising: a second breathing portion provided in the second opposing portion.

[0071] [Aspect 13] the first junction box has a first protrusion that protrudes toward the second junction box, 13. The power storage device according to any one of aspects 8 to 12, wherein the second junction box has a second protrusion that protrudes toward the first junction box.

[0072] In this embodiment, the dimensions between the junction boxes are reduced by the protrusions, so that gas discharged from any of the power storage stacks is more reliably prevented from reaching the breathing membrane.

[0073] [Aspect 14] Aspect 14. The power storage device according to any one of aspects 8 to 13, wherein the length of the breathing film in the second direction is greater than the length between the first junction box and the second junction box in the second direction.

[0074] In this embodiment, the air that flows into the case through the breathing membrane comes into contact with the junction box, thereby preventing the air that flows into the case from reaching the storage stack and causing blasting or other problems.

[0075] [Aspect 15] a pressure relief valve provided in the case for relieving pressure within the case; the case includes an upper cover that covers the first power storage stack, the second power storage stack, the first junction box, and the second junction box; Aspect 15. The energy storage device of any one of aspects 8 to 14, wherein the pressure release valve is provided in a portion of the upper cover above an inter-box space between the first junction box and the second junction box.

[0076] In this embodiment, gas discharged from either of the storage stacks primarily flows toward the inter-box space between the first junction box and the second junction box, where it changes direction upward and flows toward the pressure release valve, thereby reducing the flow rate of the gas discharged from the case.

[0077] 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]

[0078] 1 Energy storage device, 110 First energy storage stack, 111 Energy storage cell, 111a Safety valve, 120 Second energy storage stack, 210 First bus bar, 220 Second bus bar, 310 First junction box, 312 First connector, 314 First protrusion, 320 Second junction box, 322 Second connector, 324 Second protrusion, 400 Covering plate, 500 Case, 510 Lower case, 512 Bottom wall, 514 Surrounding wall, 514a Side wall, 520 Upper cover, 521 First base portion, 522 Second base portion, 523 Middle portion, 525 Shielding portion, 525a Shielding plate, 600 Pressure release valve, 700 Breathing membrane, R Opposing area, R1 First opposing portion, R2 Second opposing portion, R3 Middle portion, S1 Wiring space, S2 Interbox space, S3 contralateral 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 first junction box arranged in a position facing, in the first direction, the first power storage stack that is arranged outermost in the first direction among the plurality of first power storage stacks; a second junction box disposed at a position facing the second power storage stack in the first direction and facing the first junction box in the second direction; a case that accommodates the plurality of first power storage stacks, the plurality of second power storage stacks, the first junction box, and the second junction box; a pressure relief valve provided in the case for releasing pressure inside the case; the case includes an upper cover that covers the plurality of first power storage stacks, the plurality of second power storage stacks, the first junction box, and the second junction box; an inter-box space is formed between the first junction box and the second junction box, The pressure release valve is provided in a portion of the upper cover above the inter-box space.

2. The upper cover further includes a shielding portion provided on an inner surface thereof, each of the first power storage stack and the second power storage stack includes a plurality of power storage cells; each of the storage cells includes a safety valve provided at a position facing the upper cover; The power storage device according to claim 1 , wherein the shielding portion is provided on a path connecting the safety valve and the pressure release valve, and has a shape that extends downward from the upper cover.

3. a breathing membrane provided in the case for adjusting the pressure inside the case by allowing gas to pass between the inside of the case and the outside of the case; the case has a sidewall formed on a side opposite to a side on which the first and second power storage stacks are arranged, with respect to the first junction box and the second junction box; The power storage device according to claim 1 , wherein the breathing membrane is provided on the side wall.

4. a first bus bar that connects a pair of the first power storage stacks adjacent to each other in the first direction and is arranged in an arrangement space between the plurality of first power storage stacks and the plurality of second power storage stacks; a second bus bar that connects a pair of the second power storage stacks adjacent to each other in the first direction and is routed in the routing space; 2. The energy storage device according to claim 1, further comprising: a cover plate disposed between the plurality of first energy storage stacks and the plurality of second energy storage stacks, the cover plate covering the first bus bar and the second bus bar from above.

5. The upper cover is a first base portion covering the plurality of first power storage stacks; a second base portion covering the plurality of second power storage stacks; an intermediate portion provided between the first base portion and the second base portion and extending along the first direction; The power storage device according to claim 1 , wherein the intermediate portion is located above the inter-box space and protrudes from the first base portion and the second base portion.

6. The upper cover is a first base portion covering the plurality of first power storage stacks; a second base portion covering the plurality of second power storage stacks; an intermediate portion provided between the first base portion and the second base portion and extending along the first direction; The power storage device according to claim 1 , wherein the intermediate portion is located above the inter-box space and has a bending rigidity lower than a bending rigidity of the first base portion and a bending rigidity of the second base portion.

7. 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 first junction box arranged in a position facing, in the first direction, the first power storage stack that is arranged outermost in the first direction among the plurality of first power storage stacks; a second junction box disposed at a position facing the second power storage stack in the first direction and facing the first junction box at an interval in the second direction; a case that accommodates the plurality of first power storage stacks, the plurality of second power storage stacks, the first junction box, and the second junction box; a pressure relief valve provided in the case for releasing pressure inside the case; a breathing membrane provided in the case, which adjusts the pressure inside the case by allowing gas to pass between the inside of the case and the outside of the case; the case includes an upper cover that covers the plurality of first power storage stacks, the plurality of second power storage stacks, the first junction box, and the second junction box; the pressure release valve is provided in a portion of the upper cover between the plurality of first power storage stacks and the plurality of second power storage stacks and above a space outside the plurality of first power storage stacks and the plurality of second power storage stacks in the first direction, the case has a sidewall formed on a side opposite to a side on which the first power storage stacks and the second power storage stacks are arranged, with the pressure release valve as a reference; The breathing membrane is provided on the side wall.

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