Energy storage device

Abstract

To provide a power storage device which can suppress damage of a breathing membrane.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 500; and a breathing membrane 700. The case 500 has a side wall 514a. The side wall 514a has an opposing region R. The opposing region R extends from a site a1 that faces, in a first direction, the outer end portion of the first junction box 310 in a second direction, to a site a2 that faces, in the first direction, the outer end portion of the second junction box 320 in the second direction. The breathing membrane 700 is provided in the opposing region R.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] This disclosure relates to a power storage device.

Background Art

[0002] For example, Japanese Patent Translation Publication No. 2022-516519 discloses a power battery pack including a plurality of single cells, a battery tray that houses the plurality of single cells, and a cover plate connected to the battery tray. A battery pack explosion-proof valve attached to an exhaust hole is attached to the side wall of the battery tray.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a power storage device as described in Japanese Patent Translation Publication No. 2022-516519, in order to adjust the pressure inside the case, it is conceivable to provide a breathing film on the case that allows the passage of gas between the inside and outside of the case.

[0005] On the other hand, when gas is discharged from any of the power storage stacks, there is a concern that the breathing film may be damaged when the gas comes into contact with the breathing film.

[0006] An object of this disclosure is to provide a power storage device capable of suppressing damage to the breathing film.

Means for Solving the Problems

[0007] A power storage device according to one aspect of the present disclosure comprises: a plurality of first power storage stacks arranged in a line along a first direction; a plurality of second power storage stacks arranged in a line along the first direction, facing the plurality of first power storage stacks in a second direction orthogonal to both the first direction and the vertical direction; a first junction box positioned opposite the first power storage stack that is the outermost of the plurality of first power storage stacks in the first direction; a second junction box positioned opposite the second power storage stack in the first direction and at a distance from the first junction box in the second direction; and the plurality of first power storage stacks, the plurality of second power storage stacks, the first junction box and the second junction box. The system comprises a housing case and a breathing membrane provided in the case, which adjusts the pressure inside the case by allowing the passage of gas between the inside and outside of the case, wherein the case has a side wall formed on the side opposite to the side on which the first and second energy storage stacks are arranged with respect to the first and second junction boxes, the side wall has a facing region facing the first and second junction boxes, the facing region extends from a portion facing the first direction to the outer end of the first junction box in the second direction, to a portion facing the first direction to the outer end of the second junction box in the second direction, and the breathing membrane is provided in the facing region. [Effects of the Invention]

[0008] According to this disclosure, it is possible to provide an energy storage device that can suppress damage to the respiratory membrane. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic perspective view of an energy storage device in one embodiment of the present disclosure. [Figure 2]Figure 1 is a schematic perspective view showing the energy storage device with the upper cover and protective plate removed. [Figure 3] This is a cross-sectional view taken along line III-III in Figure 1. [Figure 4] This is a schematic plan view showing the energy storage device with the upper cover and protective plate removed. [Figure 5] This is a partial enlargement view of Figure 4. [Figure 6] This is a cross-sectional view along the line VI-VI in Figure 4. [Figure 7] This diagram schematically shows a modified example of an energy storage device. [Figure 8] This diagram schematically shows a modified example of an energy storage device. [Figure 9] This diagram schematically shows a modified example of an energy storage device. [Figure 10] This diagram schematically shows a modified version of the upper cover. [Figure 11] Figure 10 shows a cross-sectional view along the line XI-XI. [Figure 12] This diagram schematically shows a modified version of the upper cover. [Modes for carrying out the invention]

[0010] Embodiments of this disclosure will be described with reference to the drawings. In the drawings referred to below, the same or equivalent components are given the same number.

[0011] Figure 1 is a schematic perspective view of an energy storage device in one embodiment of the present disclosure. Figure 2 is a schematic perspective view of the energy storage device shown in Figure 1 with the upper cover and protective plate removed. Figure 3 is a cross-sectional view taken along line III-III in Figure 1. Figure 4 is a schematic plan view of the energy storage device with the upper cover and protective plate removed. Figure 5 is a partially enlarged view of Figure 4. Figure 6 is a cross-sectional view taken along line VI-VI in Figure 4. This energy storage device 1 is mounted, for example, on the bottom of a vehicle.

[0012] As shown in FIGS. 1 to 6, the power storage device 1 includes 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, a covering plate 400, a case 500, a pressure release valve 600, and a breathing membrane 700.

[0013] The plurality of first power storage stacks 110 are arranged to line up in the first direction. In the present embodiment, the plurality of first power storage stacks 110 include six first power storage stacks 110. However, the number of the 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 orthogonal to both the first direction and the vertical direction.

[0014] 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 line up in the first direction. Note that the plurality of power storage cells 111 may be arranged to line up in the second direction. Each power storage cell 111 is formed in a flat rectangular parallelepiped shape. Examples of each power storage cell 111 include a lithium-ion battery. Each power storage cell 111 may be configured by 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, that is, on the upper surface of the housing of the power storage cell 111.

[0015] The plurality of second power storage stacks 120 face the plurality of first power storage stacks 110 in the second direction and are arranged to line up in the first direction. In the present embodiment, the plurality of second power storage stacks 120 include six second power storage stacks 120. However, the number of the 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.

[0016] 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 in the layout space S1 (see FIG. 3) between the plurality of first power storage stacks 110 and the plurality of second power storage stacks 120.

[0017] 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 in the layout space S1.

[0018] The first junction box 310 is arranged at a position facing the first power storage stack 110 arranged on the outermost side in the first direction (for example, the front side in the longitudinal direction of the vehicle) among the plurality of first power storage stacks 110. The first junction box 310 houses relays, fuses, etc. 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 arranged at a position facing the second power storage stack 120 in the first direction and spaced apart from the first junction box 310 in the second direction. That is, a space S2 between the boxes (see FIG. 4) is formed between the first junction box 310 and the second junction box 320. The space S2 between the boxes is a space through which the gas discharged from any of the power storage stacks 110, 120 can pass. The second junction box 320 houses relays, fuses, etc. As shown in FIG. 2, in the present 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 first junction box 310 has a first projection 314 that protrudes toward the second junction box 320. The second junction box 320 has a second projection 324 that protrudes toward the first junction box 310. Each projection 314, 324 reduces the flow area of ​​the space S2 between the boxes.

[0021] As shown in Figure 4, the covering plate 400 covers the first busbar 210 and the second busbar 220 from above. The covering plate 400 is positioned between a plurality of first energy storage stacks 110 and a plurality of second energy 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 made by solidifying natural inorganic minerals by heat pressing. The covering plate 400 has the function of shielding against gas ejected upward from any of the energy storage stacks from contacting each of the busbars 210 and 220. Note that the covering plate 400 is not shown in Figures 2, 4 and 5.

[0022] The case 500 houses 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, and a covering plate 400. The case 500 has a lower case 510 and an upper cover 520.

[0023] The lower case 510 is open upwards. The lower case 510 has a bottom wall 512, a peripheral wall 514, and a partition 516.

[0024] The bottom wall 512 supports each of the energy storage stacks 110, 120.

[0025] The peripheral wall 514 rises from the periphery of the bottom wall 512. The peripheral wall 514 surrounds the multiple first energy storage stacks 110 and the multiple second energy storage stacks 120. The peripheral wall 514 is formed in a roughly rectangular cylindrical shape.

[0026] The peripheral wall 514 includes a side wall 514a formed on the side opposite to the side (left side in Figure 4) where the multiple first energy storage stacks 110 and the multiple second energy storage stacks 120 are arranged relative to the first junction box 310 and the second junction box 320. The side wall 514a extends along the second direction.

[0027] The partition 516 separates the multiple first energy storage stacks 110 from the multiple second energy 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 Figure 3, the space S1 is formed between the partition 516 and the covering plate 400.

[0028] The upper cover 520, together with the lower case 510, houses 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, and a covering plate 400. The peripheral edge of the upper cover 520 is fixed to the upper end of the peripheral wall 514 by bolts or the like.

[0029] As shown in Figure 6, a shielding portion 525 is provided on the inner surface of the upper cover 520. The shielding portion 525 is located on the path connecting the safety valve 111a and the pressure relief valve 600. In this embodiment, the shielding portion 525 is located on the inner surface of the upper cover 520 in front of each energy storage stack 110, 120. The shielding portion 525 is located above the inter-box space S2. The shielding portion 525 has a shape that extends downward from the upper cover 520.

[0030] As shown in Figure 6, the shielding portion 525 may have a shielding plate 525a extending downward from the inner surface of the upper cover 520. Preferably, the lower end of the shielding plate 525a is located below the covering plate 400.

[0031] The pressure relief valve 600 is provided in the case 500. The pressure relief valve 600 releases the pressure inside the case 500. The pressure relief valve 600 opens when the pressure inside the case 500 exceeds a reference value. The pressure relief valve 600 is composed of a check valve. As shown in Figures 4 to 6, the pressure relief valve 600 is provided in the upper cover 520 between the plurality of first energy storage stacks 110 and the plurality of second energy storage stacks 120, and in the portion outside the plurality of first energy storage stacks 110 and the plurality of second energy storage stacks 120 in the first direction. In this embodiment, the pressure relief valve 600 is provided in the upper part of the upper cover 520 above the inter-box space S2.

[0032] The breathing membrane 700 is provided in the case 500. The breathing membrane 700 regulates 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 located on the side opposite to the side where the energy storage stacks 110 and 120 are arranged, with respect to the pressure relief valve 600. In this embodiment, the breathing membrane 700 is provided in 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.

[0033] As shown in Figures 4 and 5, the respiratory membrane 700 is provided on the outer surface of the opposing region R of the side wall 514a that faces the first junction box 310 and the second junction box 320. As shown in Figure 4, the opposing region R extends from a1, which faces the outer end of the first junction box 310 in the second direction, to a2, which faces the outer end of the second junction box 320 in the second direction, and the outer end of the second junction box 320 in the second direction. In Figures 4 and 5, the opposing region R is indicated by dots.

[0034] The opposing region R has a first opposing portion R1, a second opposing portion R2, and an intermediate portion R3. The first opposing portion R1 faces the first junction box 310. The first opposing portion R1 is the region that overlaps with the first junction box 310 in the first direction. The second opposing portion R2 faces the second junction box 320. The second opposing portion R2 is the region that overlaps with the second junction box 320 in the first direction. In this embodiment, the area of ​​the second opposing portion R2 is larger than the area of ​​the first opposing portion R1. The intermediate portion R3 faces the inter-box space S2. The intermediate portion R3 is located between the first opposing portion R1 and the second opposing portion R2. In this embodiment, the respiratory membrane 700 is provided in the intermediate portion R3.

[0035] As shown in Figure 5, the length D2 of the respiratory membrane 700 in the second direction is greater than the length D1 between the first junction box 310 and the second junction box 320 in the second direction. In this embodiment, length D1 is the length between each of the protrusions 314, 324.

[0036] As described above, in the energy storage device 1 of this embodiment, when gas is discharged from either of the energy storage stacks 110 or 120, the gas mainly heads towards the inter-box space S2 between the first junction box 310 and the second junction box 320, where it changes direction upward and heads towards the pressure relief valve 600, thus reducing the flow velocity of the gas discharged from the case 500.

[0037] Furthermore, in the above embodiment, the breathing 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 direction of gas flow discharged from either of the energy storage stacks 110, 120. Therefore, the gas discharged from either of the energy storage stacks 110, 120 collides with each junction box 310, 320 before reaching the breathing membrane 700. Moreover, since the space S2 between the boxes acts as a buffer region, the exhaust gas reaching the breathing membrane 700 and the resulting damage to the breathing membrane 700 are suppressed.

[0038] Furthermore, if gas is generated from any of the energy storage stacks 110, 120 and air flows into the case 500 through the breathing membrane 700, that air will come into contact with each of the junction boxes 310, 320, thereby suppressing the air that has flowed into the case 500 from reaching the energy storage stacks 110, 120 and the resulting generation of blast from the safety valve 111a.

[0039] Modifications of the above embodiment will be described below.

[0040] <First variation> As shown in Figure 7, if the outer shape of the second junction box 320 is larger than the outer shape of the first junction box 310, the respiratory membrane 700 may be provided in the second opposing portion R2.

[0041] <Second variation> As shown in Figure 8, the respiratory membrane 700 may have a first respiratory portion 710 provided on the first opposing portion R1 and a second respiratory portion 720 provided on the second opposing portion R2. The configuration of each respiratory portion 710, 720 is the same as the configuration of the respiratory membrane 700 in the above embodiment.

[0042] <Third variation> As shown in Figure 9, the lower case 510 may have an opposite side space S3 located between the plurality of first energy storage stacks 110 and the plurality of second energy storage stacks 120, and on the opposite side from the side where the inter-box space S2 is located relative to the plurality of first energy storage stacks 110 and the plurality of second energy storage stacks 120. In this case, the pressure relief valve 600 may be provided in the upper cover 520 in the portion above the opposite side space S3.

[0043] In this case, the respiratory membrane 700 is provided on the side wall 514b of the peripheral wall 514, which is formed on the side opposite to the side where the energy storage stacks 110 and 120 are arranged, with reference to the pressure relief valve 600.

[0044] <Fourth variation> As shown in Figures 10 and 11, the upper cover 520 may have a first base portion 521, a second base portion 522, and an intermediate portion 523.

[0045] The first base portion 521 covers a plurality of first energy storage stacks 110. The second base portion 522 covers a plurality of second energy storage stacks 120. Each base portion 521, 522 extends along a first direction. Each base portion 521, 522 may be formed in a flat plate shape.

[0046] The intermediate section 523 is provided between the first base section 521 and the second base section 522. The intermediate section 523 extends along the first direction. The intermediate section 523 is located above the inter-box space S2. The intermediate section 523 protrudes from each of the base sections 521 and 522. As a result, a space S4 is formed between the intermediate section 523 and the covering plate 400.

[0047] In this example, the pressure relief valve 600 is located in the intermediate section 523.

[0048] <Fifth variation> As shown in Figure 12, the intermediate portion 523 of the upper cover 520 may have a lower bending stiffness than the bending stiffness of each base portion 521, 522. In this example, each base portion 521, 522 has ribs extending along the second direction. However, the thickness of each base portion 521, 522 may be greater than the thickness of the intermediate portion 523. Alternatively, the intermediate portion 523 may have a plurality of grooves (deformation-promoting portions) spaced apart from each other in the second direction and each extending along the first direction.

[0049] In this embodiment, the intermediate portion 523 deforms to bulge upward relative to the base portions 521 and 522 when the internal pressure of the case 500 increases, thereby forming an exhaust passage between the upper cover 520 and the covering plate 400.

[0050] Those skilled in the art will understand that the exemplary embodiments described above are specific examples of the following embodiments.

[0051] [Aspect 1] Multiple first energy storage stacks arranged in a line along the first direction, A plurality of second energy storage stacks are arranged facing the plurality of first energy storage stacks in a second direction perpendicular to both the first direction and the vertical direction, and are arranged in line along the first direction, The first energy storage stack, which is the outermost of the plurality of first energy storage stacks in the first direction, and the first junction box, which is positioned opposite to the first direction, A second junction box is positioned facing the second energy storage stack in the first direction and facing the first junction box in the second direction, A case housing the plurality of first energy storage stacks, the plurality of second energy storage stacks, the first junction box, and the second junction box, The case is provided with a pressure relief valve that releases the pressure inside the case, The case includes an upper cover that covers the plurality of first energy storage stacks, the plurality of second energy storage stacks, the first junction box, and the second junction box. A box-to-box space is formed between the first junction box and the second junction box. The pressure relief valve is provided in the upper part of the upper cover above the space between the boxes, and is part of the energy storage device.

[0052] In this energy storage device, when gas is discharged from any of the energy storage stacks, the gas primarily flows into the inter-box space between the first and second junction boxes, where it changes direction upwards and heads towards the pressure relief valve, thus reducing the flow velocity of the gas discharged from the case.

[0053] [Aspect 2] The upper cover further comprises a shielding portion provided on its inner surface, Each of the first energy storage stack and the second energy storage stack includes a plurality of energy storage cells, Each of the aforementioned energy storage cells includes a safety valve located opposite the upper cover, The energy storage device according to embodiment 1, wherein the shielding portion is provided on the path connecting the safety valve and the pressure relief valve and has a shape that extends downward from the upper cover.

[0054] In this embodiment, gas and blast discharged from the safety valve are blocked by the shielding unit before reaching the pressure relief valve, thereby further reducing the flow velocity of the gas discharged from the pressure relief valve and suppressing the arrival of blast at the pressure relief valve.

[0055] [Aspect 3] The case is further provided with a breathing membrane that adjusts the pressure inside the case by allowing the passage of gas between the inside and outside of the case, The case has a side wall formed on the side opposite to the side on which the plurality of first energy storage stacks and the plurality of second energy storage stacks are arranged, with reference to the first junction box and the second junction box. The energy storage device according to embodiment 1 or 2, wherein the respiratory membrane is provided on the side wall.

[0056] In this embodiment, since two junction boxes are placed between the breathing membrane and each energy storage stack, air flowing into the case through the breathing membrane and reaching the energy storage stacks, as well as the resulting blast generation, are suppressed.

[0057] [Aspect 4] A pair of first energy storage stacks adjacent to each other in the first direction are connected, and a first busbar is routed in the routing space between the plurality of first energy storage stacks and the plurality of second energy storage stacks, A pair of the second energy storage stacks adjacent to each other in the first direction are connected, and a second busbar is routed in the routing space, The energy storage device according to any one of embodiments 1 to 3, further comprising a covering plate disposed between the plurality of first energy storage stacks and the plurality of second energy storage stacks, and covering the first busbar and the second busbar from above.

[0058] In this embodiment, the space between each energy storage stack is utilized as a routing space for routing each busbar, and furthermore, the covering plate effectively suppresses contact between the gas discharged from the energy storage stack and each busbar.

[0059] [Aspect 5] The aforementioned upper cover is A first base portion covering the plurality of first energy storage stacks, A second base portion covering the plurality of second energy storage stacks, It has an intermediate portion provided between the first base portion and the second base portion, extending along the first direction, The energy storage device according to any one of embodiments 1 to 4, wherein the intermediate portion is located above the space between the boxes and rises from the first base portion and the second base portion.

[0060] In this embodiment, an exhaust passage is formed between the intermediate section and each energy storage stack, so that the gas discharged from the energy storage stack is effectively guided toward the pressure relief valve.

[0061] [Aspect 6] The aforementioned upper cover is A first base portion covering the plurality of first energy storage stacks, A second base portion covering the plurality of second energy storage stacks, It has an intermediate portion provided between the first base portion and the second base portion, extending along the first direction, The energy storage device according to any one of embodiments 1 to 4, wherein the intermediate portion is located above the space between the boxes and has a bending rigidity lower than that of the first base portion and the second base portion.

[0062] In this embodiment, when the internal pressure of the case increases, the intermediate section deforms in a direction that separates it from each base section and each energy storage stack, thereby forming an exhaust passage between the intermediate section and each energy storage stack, and thus effectively guiding the gas discharged from the energy storage stack toward the pressure relief valve.

[0063] [Aspect 7] Multiple first energy storage stacks arranged in a line along the first direction, A plurality of second energy storage stacks are arranged facing the plurality of first energy storage stacks in a second direction perpendicular to both the first direction and the vertical direction, and are arranged in line along the first direction, The first energy storage stack, which is the outermost of the plurality of first energy storage stacks in the first direction, and the first junction box, which is positioned opposite to the first direction, A second junction box is positioned opposite the second energy storage stack in the first direction and opposite the first junction box at a distance in the second direction, A case housing the plurality of first energy storage stacks, the plurality of second energy storage stacks, the first junction box, and the second junction box, A pressure relief valve is provided in the aforementioned case for releasing the pressure inside the case, The case is provided with a breathing membrane that adjusts the pressure inside the case by allowing the passage of gas between the inside and outside of the case, The case includes an upper cover that covers the plurality of first energy storage stacks, the plurality of second energy storage stacks, the first junction box, and the second junction box. The pressure relief valve is provided in the upper cover between the plurality of first energy storage stacks and the plurality of second energy storage stacks, and in the upper part of the space outside the plurality of first energy storage stacks and the plurality of second energy storage stacks in the first direction. The case has a side wall formed on the side opposite to the side on which the plurality of first energy storage stacks and the plurality of second energy storage stacks are arranged, with reference to the pressure relief valve. The respiratory membrane is an energy storage device provided on the side wall.

[0064] In this energy storage device, if gas is discharged from any of the energy storage stacks, the gas will flow towards the space opposite to the side where each junction box is located, where it will change direction upwards and head towards the pressure relief valve. This suppresses the arrival of exhaust gas at the junction boxes and reduces the flow velocity of the gas discharged from the case.

[0065] [Aspect 8] Multiple first energy storage stacks arranged in a line along the first direction, A plurality of second energy storage stacks are arranged facing the plurality of first energy storage stacks in a second direction perpendicular to both the first direction and the vertical direction, and are arranged in line along the first direction, The first energy storage stack, which is the outermost of the plurality of first energy storage stacks in the first direction, and the first junction box, which is positioned opposite to the first direction, A second junction box is positioned opposite the second energy storage stack in the first direction and opposite the first junction box at a distance in the second direction, A case housing the plurality of first energy storage stacks, the plurality of second energy storage stacks, the first junction box, and the second junction box, The case is provided with a breathing membrane that adjusts the pressure inside the case by allowing the passage of gas between the inside and outside of the case, The case has a side wall formed on the side opposite to the side on which the first energy storage stack and the second energy storage stack are arranged, with reference to the first junction box and the second junction box. The side wall has a facing region that faces the first junction box and the second junction box, The opposing region extends from the portion facing the outer end of the first junction box in the second direction to the portion facing the outer end of the second junction box in the second direction to the portion facing the first direction. The respiratory membrane is an energy storage device provided in the opposing region.

[0066] In this energy storage device, a breathing membrane is provided in the opposing region of the side wall of the case. In other words, in the direction of gas flow from any of the energy storage stacks, the breathing membrane is located downstream of each junction box. Therefore, the gas discharged from the energy storage stacks collides with each junction box before reaching the breathing membrane. Furthermore, the space between each junction box acts as a buffer zone, which suppresses exhaust gas from reaching the breathing membrane and the resulting damage to the breathing membrane.

[0067] [Aspect 9] The opposing region includes an intermediate portion facing the inter-box space between the first junction box and the second junction box, The energy storage device according to embodiment 8, wherein the respiratory membrane is provided in the intermediate portion.

[0068] [Aspect 10] The opposing region is, A first opposing part facing the first junction box, It includes a second opposing portion facing the second junction box, The energy storage device according to embodiment 8, wherein the respiratory membrane is provided on the first opposing portion or the second opposing portion.

[0069] In this embodiment, since the breathing membrane is located downstream of one of the junction boxes, exhaust gases are more reliably prevented from reaching the breathing membrane.

[0070] [Aspect 11] The external dimensions of the second junction box are larger than those of the first junction box. The energy storage device according to embodiment 10, wherein the respiratory membrane is provided on the second opposing portion.

[0071] [Aspect 12] The opposing region is, A first opposing part facing the first junction box, It includes a second opposing portion facing the second junction box, The respiratory membrane is The first breathing section provided in the first opposing section, The energy storage device according to embodiment 8, further comprising a second breathing section provided on the second opposing section.

[0072] [Aspect 13] The first junction box has a first projection that protrudes toward the second junction box, The energy storage device according to any one of embodiments 8 to 12, wherein the second junction box has a second projection that protrudes toward the first junction box.

[0073] In this embodiment, the dimensions between junction boxes are reduced by each protrusion, thus more reliably preventing gases emitted from any of the energy storage stacks from reaching the breathing membrane.

[0074] [Aspect 14] The energy storage device according to any one of embodiments 8 to 13, wherein the length of the breathing membrane in the second direction is greater than the length between the first junction box and the second junction box in the second direction.

[0075] In this embodiment, since the air flowing into the case through the breathing membrane comes into contact with the junction box, the air flowing into the case reaching the energy storage stack and the resulting generation of blast are suppressed.

[0076] [Aspect 15] The case is provided with a pressure relief valve that releases the pressure inside the case, The case includes an upper cover that covers the first energy storage stack, the second energy storage stack, the first junction box, and the second junction box. The energy storage device according to any one of embodiments 8 to 14, wherein the pressure relief valve is provided in the upper part of the upper cover above the inter-box space between the first junction box and the second junction box.

[0077] In this embodiment, the gas discharged from either energy storage stack mainly heads towards the inter-box space between the first and second junction boxes, where it changes direction upwards and heads towards the pressure relief valve, thus reducing the flow velocity of the gas discharged from the case.

[0078] It should be noted that the embodiments disclosed herein are illustrative in all respects and not restrictive. The scope of this disclosure is defined by the claims rather than the description of the embodiments above, and includes all modifications within the meaning and scope equivalent to the claims. [Explanation of Symbols]

[0079] 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 Peripheral wall, 514a Side wall, 520 Upper cover, 521 First base section, 522 Second base section, 523 Intermediate section, 525 Shielding section, 525a Shielding plate, 600 Pressure relief valve, 700 Breathing membrane, R Opposing region, R1 First opposing section, R2 Second opposing section, R3 Intermediate section, S1 Wiring space, S2 Inter-box space, S3 opposite-side space.

Claims

1. Multiple first energy storage stacks arranged in a line along the first direction, A plurality of second energy storage stacks are arranged facing the plurality of first energy storage stacks in a second direction perpendicular to both the first direction and the vertical direction, and are arranged in line along the first direction, A first junction box is positioned opposite the first energy storage stack, which is the outermost of the plurality of first energy storage stacks in the first direction, and the first energy storage stack which is positioned opposite the first direction. A second junction box is positioned opposite the second energy storage stack in the first direction and opposite the first junction box at a distance in the second direction, A case housing the plurality of first energy storage stacks, the plurality of second energy storage stacks, the first junction box, and the second junction box, The case is provided with a breathing membrane that adjusts the pressure inside the case by allowing the passage of gas between the inside and outside of the case, The case has a side wall formed on the side opposite to the side on which the first energy storage stack and the second energy storage stack are arranged, with reference to the first junction box and the second junction box. The side wall has a facing region that faces the first junction box and the second junction box, The opposing region extends from the portion facing the first direction to the outer end of the first junction box in the second direction, to the portion facing the first direction to the outer end of the second junction box in the second direction, The respiratory membrane is an energy storage device provided in the opposing region.

2. The opposing region includes an intermediate portion facing the inter-box space between the first junction box and the second junction box, The energy storage device according to claim 1, wherein the respiratory membrane is provided in the intermediate portion.

3. The opposing region is, A first opposing part facing the first junction box, It includes a second opposing portion facing the second junction box, The energy storage device according to claim 1, wherein the respiratory membrane is provided in the first opposing portion or the second opposing portion.

4. The external dimensions of the second junction box are larger than those of the first junction box. The energy storage device according to claim 3, wherein the respiratory membrane is provided on the second opposing portion.

5. The opposing region is, A first opposing part facing the first junction box, It includes a second opposing portion facing the second junction box, The respiratory membrane is The first breathing section provided in the first opposing section, The energy storage device according to claim 1, further comprising a second breathing section provided on the second opposing section.

6. The first junction box has a first projection that protrudes toward the second junction box, The energy storage device according to claim 1, wherein the second junction box has a second projection that protrudes toward the first junction box.

7. The energy storage device according to claim 1, wherein the length of the breathing membrane in the second direction is greater than the length between the first junction box and the second junction box in the second direction.

8. The case is provided with a pressure relief valve that releases the pressure inside the case, The case includes the first energy storage stack, the second energy storage stack, the first junction box, and an upper cover that covers the second junction box. The energy storage device according to claim 1, wherein the pressure relief valve is provided in the upper part of the upper cover above the inter-box space between the first junction box and the second junction box.

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