Power storage device

Abstract

To provide a power storage device capable of reducing the force of a substance discharged from a power storage cell.SOLUTION: The electric storage device 100 includes an electric storage cell 10 provided with a pressure release valve SV, a housing 20 (placement member) in which the electric storage cell 10 is placed, and a sheet member 30 (heat-resistant member) provided in the housing 20. The sheet member 30 includes a slack portion 31 arranged in a slack state.SELECTED DRAWING: Figure 6

Description

[Technical Field]

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

[0002] Japanese Patent Application Laid-Open Publication No. 2023-046977 (Patent Document 1) discloses a battery pack structure including a power storage module including a plurality of secondary battery cells having a smoke exhaust port, and a heat insulating material is arranged above the smoke exhaust port of the power storage module. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-046977 Summary of the Invention [Problem to be solved by the invention]

[0004] In the battery pack structure (energy storage device) described in Patent Document 1 above, if high-temperature gas or internal contents are forcefully discharged toward the insulation from the smoke exhaust port of the secondary battery cell (energy storage cell), there is a possibility that the insulation or the components surrounding the insulation may be affected.

[0005] The present disclosure has been made to solve the above-mentioned problems, and an object of the present disclosure is to provide an electricity storage device that can reduce the momentum of waste discharged from an electricity storage cell. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, there is provided an electric storage device including an electric storage cell provided with a pressure release valve, a mounting member on which the electric storage cell is mounted, and a heat-resistant member provided on the mounting member. The heat-resistant member includes a slack portion that is disposed in a slack state. [Effects of the Invention]

[0007] According to the present disclosure, the momentum of the discharged matter discharged from the power storage cell can be reduced. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram schematically showing a vehicle equipped with a power storage device according to a first embodiment. [Figure 2] 1 is a perspective view showing an electricity storage device and a vehicle body according to a first embodiment. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. [Figure 4] FIG. 2 is a perspective view showing the configuration of a storage cell. [Figure 5] FIG. 2 is a perspective view showing the configuration of a lower case. [Figure 6] FIG. 2 is a partially enlarged cross-sectional view showing the configuration of a sheet member according to the first embodiment. [Figure 7] FIG. 2 is a plan view showing a smoke exhaust hole and a sheet member according to the first embodiment. [Figure 8] FIG. 3 is a partially enlarged cross-sectional view showing a state in which a slack portion of the sheet member according to the first embodiment is taut. [Figure 9] FIG. 3 is a partially enlarged cross-sectional view showing a state in which a sagging portion of the sheet member according to the first embodiment has been broken. [Figure 10] 9 is a partially enlarged cross-sectional view showing a state in which a sagging portion of the sheet member according to the first embodiment protrudes to the opposite side to that shown in FIG. 8. FIG. [Figure 11] FIG. 4 is a diagram showing the length of a sagging portion of a sheet member according to the first embodiment. [Figure 12] FIG. 2 is a partially enlarged perspective view showing the configuration in the vicinity of an exhaust valve of the electricity storage device according to the first embodiment. [Figure 13] FIG. 1 is a partially enlarged cross-sectional view showing the configuration of a sheet member according to a first modified example of the first embodiment. [Figure 14] FIG. 2 is a partially enlarged cross-sectional view (FIG. 2) showing the configuration of a sheet member according to a first modified example of the first embodiment. [Figure 15] FIG. 1 is a partially enlarged cross-sectional view showing the configuration of a sheet member according to a second modified example of the first embodiment. [Figure 16] FIG. 2 is a partially enlarged cross-sectional view (FIG. 2) showing the configuration of a sheet member according to a second modified example of the first embodiment. [Figure 17] FIG. 10 is a diagram schematically illustrating a mobility robot equipped with a power storage device according to a second embodiment. [Figure 18] FIG. 10 is a perspective view showing the configuration of an electricity storage device according to a second embodiment. [Figure 19] FIG. 5 is a cross-sectional view showing the configuration of an electricity storage device according to a second embodiment. [Figure 20] 20 is a cross-sectional view of the electricity storage device taken along line XX-XX in FIG. 19. [Figure 21] 20 is a cross-sectional view of the electricity storage device taken along line XXI-XXI in FIG. 19. [Figure 22] FIG. 20 is a diagram showing a state in which the slack portion of FIG. 19 is stretched. [Figure 23] 23 is a cross-sectional view of the electricity storage device taken along line XXIII-XXIII in FIG. 22. [Figure 24] 24 is a cross-sectional view of the electricity storage device taken along line XXIV-XXIV in FIG. 22. [Figure 25] 10A and 10B are diagrams showing modified examples of the configuration of the slack portion. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] 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] [First embodiment] An electricity storage device 100 according to a first embodiment of the present disclosure will be described with reference to FIGS. 1 to 12. FIG. 1 is a side view schematically showing a vehicle 900 including the electricity storage device 100 according to the first embodiment. In this specification, the X direction, Y direction, and Z direction are directions that are perpendicular to one another. For example, the X direction and the Y direction are the front-to-rear direction and the width direction of the vehicle 900 when the electricity storage device 100 is mounted on the vehicle 900, respectively. The X1 direction and the X2 direction are the front and rear of the vehicle, respectively. The Y1 direction and the Y2 direction are the left and right sides of the vehicle, respectively. The Z direction is the up-down (vertical) direction. The Y direction and the Z direction are examples of the "intersecting direction" and the "up-down direction," respectively, in the present disclosure.

[0011] 1 , vehicle 900 includes a vehicle body 910 in addition to power storage device 100. Examples of vehicle 900 include a hybrid electric vehicle, a plug-in hybrid electric vehicle, and an electric vehicle (battery electric vehicle). Vehicle body 910 includes a frame member 920. Frame member 920 is disposed on the bottom of vehicle body 910.

[0012] As shown in FIG. 2, the frame member 920 has a pair of first frames 921, a pair of second frames 922, a first cross frame 923, and a second cross frame 924.

[0013] The pair of first frames 921 face each other in the X direction. Each of the first frames 921 has a shape that extends along the Y direction.

[0014] The pair of second frames 922 face each other in the Y direction. Each second frame 922 has a shape extending along the X direction. An end of each second frame 922 in the X direction is connected to the first frame 921. The pair of second frames 922, together with the pair of first frames 921, form a substantially rectangular cylindrical frame that surrounds the power storage device 100.

[0015] The first cross frame 923 is disposed between the pair of first frames 921 and connects the pair of second frames 922 to each other.

[0016] The second cross frame 924 is disposed between the pair of first frames 921 and connects the pair of second frames 922. The second cross frame 924 is spaced apart from the first cross frame 923 in the X direction. Each of the first cross frame 923 and the second cross frame 924 constitutes, for example, a seat cross.

[0017] The power storage device 100 is attached to a frame member 920. The power storage device 100 is disposed below a first cross frame 923 and a second cross frame 924. The power storage device 100 includes four power storage stacks 101 to 104. The number of power storage stacks is not limited to four.

[0018] In the first embodiment, each of the power storage stacks 101 to 104 is formed in the shape of a rectangular parallelepiped that is long in the X direction. As shown in Fig. 2, the four power storage stacks 101 to 104 are arranged side by side along the Y direction.

[0019] Fig. 3 is a cross-sectional view taken along line III-III in Fig. 2. As shown in Fig. 3, the energy storage device 100 includes at least one energy storage cell 10 and a housing 20. At least one energy storage cell 10 is included in each of the energy storage stacks 101 to 104 (Fig. 2). In the first embodiment, a plurality of (for example, 50) energy storage cells 10 are arranged in the X direction in each of the energy storage stacks 101 to 104. In Fig. 3, the discharge direction of gas discharged from a pressure release valve SV (described later) is indicated by a dashed-dotted arrow. The housing 20 is an example of a "storage case" and "arrangement member" in the present disclosure.

[0020] A pair of end plates 10a are provided on both sides of the plurality of storage cells 10 in the X direction to sandwich the plurality of storage cells 10 from both sides in the X direction. A monitoring unit (Smart Battery Management) 10b is arranged on the outer side of each end plate 10a in the X direction.

[0021] Each storage cell 10 includes an electrode assembly 11. The electrode assembly 11 may be formed as a wound body in which a positive electrode sheet and a negative electrode sheet are wound with a separator interposed therebetween, or may be formed as a laminate in which a positive electrode sheet and a negative electrode sheet are stacked with a separator interposed therebetween. The electrode assembly 11 is formed in a shape that is long in the Y direction.

[0022] The housing 20 includes a lower case 21, an upper cover 22, and a share panel 23.

[0023] The lower case 21 includes a bottom plate 21a. The bottom plate 21a is disposed below the plurality of energy storage cells 10. The bottom plate 21a covers the plurality of energy storage cells 10 from below. The bottom plate 21a forms the bottom surface of the lower case 21. The bottom plate 21a is an example of a "lower cover" in the present disclosure.

[0024] The upper cover 22, together with the lower case 21, houses a plurality of energy storage cells 10. In the first embodiment, the upper cover 22, together with the lower case 21, houses four energy storage stacks 101-104 (FIG. 2) in a sealed state. Each of the energy storage stacks 101-104 is arranged in a cell space S1 formed by the upper cover 22 and the lower case 21. The cell space S1 is a space on the energy storage cell 10 side with respect to the bottom plate 21a. The cell space S1 is an example of a "first space" in the present disclosure.

[0025] The upper cover 22 covers the power storage stacks 101 to 104 from above. The lower case 21 covers the power storage stacks 101 to 104 from below. The peripheral edge of the upper cover 22 is connected to the peripheral edge of the lower case 21 by bolts or the like via a sealing member.

[0026] The shear panel 23 is provided below the lower case 21. The shear panel 23 covers the lower case 21 from below. The shear panel 23 has a function of protecting the lower case 21. The shear panel 23 may be formed in a flat plate shape.

[0027] The shared panel 23 is located below the plurality of energy storage cells 10 and the bottom plate 21a of the lower case 21. A smoke exhaust space S2 is formed between the bottom plate 21a and the shared panel 23. The smoke exhaust space S2 constitutes a smoke exhaust path through which gas (smoke) (hereinafter simply referred to as "gas") discharged from the energy storage cells 10 flows. The smoke exhaust space S2 is an example of a "second space" in the present disclosure.

[0028] The lower case 21 has an exhaust valve 40. The exhaust valve 40 is disposed on the rear end side (X2 side) of the lower case 21. Gas flowing through the smoke exhaust space S2 is exhausted from the exhaust valve 40 to the outside.

[0029] Fig. 4 is a perspective view showing the configuration of the energy storage cell 10. As shown in Fig. 4, each energy storage cell 10 has an electrode assembly 11 (Fig. 3), a cell case 12, a pair of external terminals 13, and a pressure release valve SV. The cell case 12 houses the electrode assembly 11.

[0030] The cell case 12 is formed in a rectangular parallelepiped shape. The cell case 12 is made of a metal such as aluminum. The energy storage cell 10 is formed to be elongated in the Y direction. Specifically, a width W1 of the energy storage cell 10 in the Y direction is larger than a width W2 of the energy storage cell 10 in the X direction. A height H1 of the energy storage cell 10 is smaller than the width W1 and larger than the width W2.

[0031] The energy storage cell 10 (cell case 12) has a short side surface 1, a short side surface 2, a long side surface 3, a long side surface 4, an upper surface 5, and a lower surface 6.

[0032] The short side surface 1 and the short side surface 2 are arranged in the Y direction. Specifically, the short side surface 1 and the short side surface 2 are one end surface and the other end surface of the energy storage cell 10 in the Y direction, respectively.

[0033] The long side surfaces 3 and 4 are arranged in the X direction. Specifically, the long side surfaces 3 and 4 are one end surface and the other end surface of the energy storage cell 10 in the X direction, respectively.

[0034] The upper surface 5 and the lower surface 6 are arranged in the Z direction. Specifically, the upper surface 5 and the lower surface 6 are the end surface on the Z1 side and the end surface on the Z2 side of the energy storage cell 10, respectively.

[0035] A pair of external terminals 13 are provided on the short side surface 1 and the short side surface 2, respectively. The pressure release valve SV is provided on the bottom surface 6. The pressure release valve SV opens when the pressure of the smoke or gas inside the cell casing 12 reaches or exceeds a certain level. In other words, the bottom surface 6 on which the pressure release valve SV is provided constitutes the pressure release surface of the cell casing 12.

[0036] FIG. 5 is a perspective view showing the configuration of the lower case 21. The lower case 21 includes an accommodation portion 21b and a plate portion 21c. The accommodation portion 21b includes a bottom plate 21a and a peripheral wall 21d. The bottom plate 21a is formed in a plate shape, and a plurality of smoke exhaust holes 21e are formed in the bottom plate 21a. The plurality of smoke exhaust holes 21e are arranged in the front-rear direction (X direction) of the vehicle 900. Furthermore, a plurality of rows of the plurality of smoke exhaust holes 21e arranged in the X direction are arranged in the Y direction (four rows in FIG. 5). The rows of the plurality of smoke exhaust holes 21e arranged in the X direction are formed below each of the power storage stacks 101 to 104 (FIG. 2). The smoke exhaust holes 21e are provided below each power storage cell 10. The smoke exhaust holes 21e are through-holes that penetrate the bottom plate 21a. Furthermore, the smoke exhaust holes 21e are an example of the "hole portion" and "through-hole" of the present disclosure.

[0037] Furthermore, instead of the plurality of smoke exhaust holes 21e arranged in the X direction, an opening that is elongated in the X direction may be formed. In the case of such an opening, when the lower case 21 is fixed to the upper cover 22, the pressure release valve SV of each of the plurality of energy storage cells 10 communicates with the opening. By providing such an opening, it is possible to easily align the opening and the pressure release valve SV.

[0038] The bottom plate 21a is formed with two holes 21j that communicate with the exhaust valves 40 (FIG. 3). For simplicity, the exhaust valves 40 are not shown in FIG.

[0039] The peripheral wall 21d is formed to extend upward from the outer peripheral edge of the bottom plate 21a. The peripheral wall 21d is formed in an annular shape. The peripheral wall 21d includes a front wall 21f disposed in the front (X1 side), a rear wall 21g disposed in the rear (X2 side), a left side wall 21h disposed on the left side (Y1 side), and a right side wall 21i disposed on the right side (Y2 side). An opening that opens upward is formed in the accommodation portion 21b. The plate portion 21c is formed to protrude horizontally from the opening edge of the accommodation portion 21b. The rear wall 21d is formed in a tapered shape toward the X2 side. The configuration of the lower case 21 is not limited to the example shown in FIG. 5.

[0040] A plurality of energy storage cells 10 are arranged in the storage section 21b. The pressure release valves SV (FIG. 4) and the smoke exhaust holes 21e of the energy storage cells 10 are arranged in the Z direction, and the pressure release valves SV and the smoke exhaust holes 21e are in communication with each other.

[0041] FIG. 6 is a partially enlarged view of the vicinity of the pressure release valve SV in FIG. 3. As shown in FIG. 6, the energy storage device 100 includes at least one sheet member 30. The sheet member 30 is disposed on the housing 20. Specifically, the sheet member 30 is disposed on the bottom plate 21a of the lower case 21. The sheet member 30 covers the smoke exhaust hole 21e from the Z1 side. As a result, the smoke exhaust hole 21e is blocked by the sheet member 30. Note that each of the multiple smoke exhaust holes 21e formed on the bottom plate 21a is blocked by a separate sheet member 30. In other words, the number of sheet members 30 is equal to the number of smoke exhaust holes 21e. Note that the multiple smoke exhaust holes 21e may be blocked by a common (single) sheet member. The sheet member 30 is an example of a "heat-resistant member" in the present disclosure.

[0042] The sheet member 30 is formed of a heat-resistant (flame-retardant) cloth-like material such as silica cloth. Silica cloth is a woven inorganic fiber sheet whose main component is silica (silicon oxide). Silica cloth is a highly flame-retardant sheet that has excellent heat resistance and maintains a certain level of strength even when used in a high-temperature environment of, for example, 1000°C. The sheet member 30 may also have heat insulating properties.

[0043] In a conventional electricity storage device, when high-temperature gas or internal contents are forcefully discharged from the pressure release valve of the electricity storage cell, there is a possibility that the surrounding components may be affected.

[0044] Therefore, in this embodiment, the sheet member 30 includes sagging portions 31 that are arranged in a sagging state. The sagging portions 31 are portions that are folded in a bellows (pleats) shape in a sagging state. Specifically, the sagging portions 31 are formed so that peaks and valleys are alternately arranged in the X direction.

[0045] By folding the sagging portion 31 in an accordion-like manner in the sagging state, it is possible to make the sagging portion 31 in the sagging state compact, and as a result, it is possible to prevent the sagging portion 31 in the sagging state from coming into contact with surrounding members.

[0046] The slack portion 31 is disposed at a position facing the pressure release valve SV. In other words, the slack portion 31 is disposed at a position overlapping the pressure release valve SV in the Z direction.

[0047] This allows the discharge of high-temperature gas and other discharged matter from the pressure release valve SV to be discharged toward the sagging portion 31. As a result, the sagging portion 31 can effectively reduce the momentum (flow velocity) of the discharged matter.

[0048] The sagging portion 31 covers the smoke exhaust hole 21e from above. The sagging portion 31 may cover the entire area of ​​the smoke exhaust hole 21e.

[0049] As a result, when a downward force is applied to sagging portion 31 and sags 31 deforms to bulge downward, smoke exhaust hole 21e can be used as space for the deformation. As a result, the force of the discharged matter from energy storage cell 10 can be easily reduced by the deformation of sagging portion 31. Furthermore, because smoke exhaust hole 21e is a through hole, contact between bottom plate 21a and sagging portion 31 can be reduced when sagging portion 31 deforms to bulge downward. As a result, the force of the discharged matter from energy storage cell 10 can be further reduced.

[0050] As shown in Fig. 7, the sheet member 30 has an oval shape similar to the smoke exhaust hole 21e. The sheet member 30 includes an outer peripheral edge portion 32. The outer peripheral edge portion 32 is fixed to the upper surface of the bottom plate 21a by adhesive bonding, bolting, or the like. The sagging portion 31 is surrounded by the outer peripheral edge portion 32. In other words, the outer peripheral edge 310 of the sagging portion 31 and the outer peripheral edge portion 32 of the sheet member 30 are connected. Note that the outer peripheral edge portion 32 may also be fixed to the lower surface of the bottom plate 21a.

[0051] Referring again to Figure 6, the sagging portion 31 has a weak portion 31a and a non-weak portion 31b. The weak portion 31a is more easily broken than the non-weak portion 31b. The non-weak portion 31b is the entire portion of the sagging portion 31 other than the weak portion 31a. The weak portion 31a and the non-weak portion 31b are examples of the "second portion" and the "first portion," respectively.

[0052] This allows the sagging portion 31 to be easily broken starting from the weak portion 31a, and as a result, the discharged matter from the electricity storage cell 10 can be easily discharged into the smoke exhaust space S2.

[0053] The fragile portion 31a has a notch 31c formed therein. The notch 31c is formed on the surface of the sagging portion 31 on the Z2 side (the side opposite to the energy storage cell 10). The notch 31c is formed in the center of the sagging portion 31 in the X direction. The notch 31c may extend in the Y direction.

[0054] 8 shows a state in which downward pressure is applied to the sagging portion 31 due to the discharge of high-temperature gas and the like from the pressure release valve SV. In this case, the sagging portion 31 changes to a taut state so that it is convex downward. Specifically, the sagging portion 31 protrudes downward. In FIG. 8, a portion of the lower side of the sagging portion 31 protrudes downward beyond the smoke exhaust port 21e.

[0055] 9 shows a state in which the sagging portion 31 is broken starting from the weakened portion 31a (FIG. 7), which allows the discharged matter from the pressure release valve SV to move from the cell space S1 to the smoke exhaust space S2 through the smoke exhaust hole 21e.

[0056] 10 is a diagram showing a state in which the pressure in the cell space S1 is lower than the pressure in the smoke exhaust space S2. In this case, the sagging portion 31 protrudes upward (towards the energy storage cell 10).

[0057] In this state, the sagging portion 31 is separated from and does not come into contact with the energy storage cell 10. In other words, a gap C is formed between the upper end of the sagging portion 31 in the upwardly projecting state and the lower end of the energy storage cell 10 (pressure release valve SV).

[0058] This makes it possible to prevent the sagging portion 31 and the storage cell 10 from coming into contact with each other, thereby making it possible to prevent the influence of heat from one of the sagging portion 31 and the storage cell 10 to the other.

[0059] 11 is a diagram showing the length of slack portion 31 in various states. Slack portion 31 has length L1 in a slack state (a state in which no external force is applied). Slack portion 31 has length L2 in a state in which the slack is eliminated (a state in which slack is stretched / extended in the X direction so that no peaks or valleys are formed).

[0060] In the first embodiment, the length L2 is 125% of the length L1. However, the relationship between the lengths L1 and L2 is not limited to this. The length L2 may be any value as long as it is 105% or more and 150% or less of the length L1.

[0061] This allows sagging portion 31 to be easily deformed by the force of the material discharged from electricity storage cell 10.

[0062] Fig. 12 is a partially enlarged perspective view of the vicinity of the exhaust valve 40. As shown in Fig. 12, two exhaust valves 40 are arranged side by side in the Y direction. In Fig. 12, the flow of gas discharged from the energy storage cell 10 is indicated by dashed arrows.

[0063] The gas from the energy storage cells 10 flows through the smoke exhaust space S2 and then flows into holes 21j formed in the lower case 21 (for example, the bottom plate 21a). The gas that flows into the holes 21j is exhausted to the outside through the exhaust valve 40.

[0064] The electricity storage device 100 further includes at least one sheet member 130. In the first embodiment, two sheet members 130 are provided. Although FIG. 12 shows an example in which the sheet member 130 has a rectangular shape, the present disclosure is not limited to this. The sheet member 130 may have the same shape as the exhaust valve 40 (circular in FIG. 12). The sheet member 130 is an example of a "heat-resistant member" in the present disclosure.

[0065] The sheet member 130 includes a sagging portion 131. The sagging portion 131 is formed in a bellows shape, similar to the sagging portion 31 (FIG. 6). Although not shown, the sagging portion 131 may also have a weak portion formed therein, similar to the sagging portion 31. Furthermore, the direction in which the peaks and valleys of the sagging portion 131 are aligned (the Y direction in FIG. 12) is not limited to the example shown in FIG. 12.

[0066] The sheet member 130 has an outer peripheral edge portion 132. The outer peripheral edge portion 132 surrounds the sagging portion 131. The outer peripheral edge portion 132 may be attached to the rear wall 21g of the lower case 21, for example.

[0067] The sagging portion 131 is formed at a position facing the exhaust valve 40. Specifically, the sagging portion 131 covers the exhaust valve 40 from the X2 side.

[0068] As a result, the momentum of the exhaust (gas) discharged from the exhaust valve 40 can be reduced by the sagging portion 131.

[0069] As described above, in the first embodiment, the sheet member 30 (130) includes the sagging portion 31 (131) that is arranged in a sagging state. Thus, since the sheet member 30 (130) provided in the housing 20 includes the sagging portion 31 (131), the sagging portion 31 (131) changes from a sagging state to a taut state due to the momentum of the discharged material from the energy storage cell 10. This allows the sagging portion 31 (131) to reduce the momentum of the discharged material. As a result, it is possible to suppress the momentum (pressure) of the discharged material from affecting the surrounding members of the sheet member 30 (130). Furthermore, since the sheet member 30 (130) is heat-resistant (flame-retardant), the strength of the sheet member 30 (130) can be maintained for a certain period of time or more when the energy storage cell 10 discharges high-temperature gas or the like. As a result, after the force of the discharged matter from the energy storage cell 10 is reduced by the slack portion 31 (131), the sheet member 30 (130) can be broken starting from the weak portion 31a or the like.

[0070] [Modification of the first embodiment] 13 and 14 show a first modified example of the first embodiment. In this example, the pressure release valve SV is provided on the upper surface 15 of the energy storage cell 110.

[0071] As shown in FIG. 13, the upper cover 22 has a lower surface 22a. The lower surface 22a faces the energy storage cells 110. An upwardly recessed recess 22b is formed in the lower surface 22a. The recess 22b is formed by side surfaces 22c and 22d arranged in the Y direction and a ceiling surface 22e connecting the upper ends of the side surfaces 22c and 22d. The side surfaces 22c and 22d each extend upward from the lower surface 22a. The side surface 22c faces the side surface 22d.

[0072] The sheet member 230 includes a sagging portion 231, a first end 232, and a second end 233. The first end 232 is the end of the sheet member 230 on the Y2 side. The second end 233 is the end of the sheet member 230 on the Y1 side. Each of the first end 232 and the second end 233 is fixed to the lower surface 22a of the upper cover 22 by adhesive bonding, bolting, or the like. The sheet member 230 is an example of a "heat-resistant member" in the present disclosure.

[0073] The sagging portion 231 connects the first end 232 and the second end 233. The sagging portion 231 is disposed at a position facing the pressure release valve SV. Note that the direction in which the peaks and valleys of the sagging portion 231 are aligned (the Y direction in FIG. 13) is not limited to the example shown in FIG.

[0074] The sagging portion 231 covers the recessed portion 22b from below. That is, the sagging portion 231 is provided at a position that overlaps with the recessed portion 22b in the up-down direction.

[0075] This allows the sagging portion 231 to deform so as to bulge upward due to the momentum of the material discharged from the energy storage cell 110, so that the sagging portion 231 can be deformed so as to bulge inward of the recess 22b. This makes it possible to prevent the deformation of the sagging portion 231 from being hindered. As a result, the momentum of the material discharged from the energy storage cell 110 can be easily reduced.

[0076] The slack portion 231 may have a notch 231c formed in the center in the Y direction, for example.

[0077] 14, recess 22b is disposed above a plurality of storage cells 110 lined up in the X direction. Specifically, recess 22b extends in the X direction along the row of storage cells 110. Sagging portion 221 extends in the X direction along recess 22b.

[0078] Gas discharged from the energy storage cell 110 (indicated by the dashed arrow in FIG. 14) breaks the sagging portion 231 and enters the recess 22b, and then flows along the recess 22b in the X direction. As a result, the gas is guided to the exhaust valve 40 (FIG. 12). Note that the sagging portion 231 does not have to extend in the X direction. For example, a plurality of sagging portions 231 may be lined up in the X direction.

[0079] 15 and 16 show a second modified example of the first embodiment. In this example, the pressure release valve SV is provided on a short side surface of the energy storage cell 210. In the example shown in Fig. 15, the pressure release valve SV is provided on a short side surface 211 of the energy storage cell 210. For simplification, external terminals are not shown in Fig. 15.

[0080] As shown in FIG. 15 , the housing 20 includes a cross member 24. The cross member 24 is disposed on an upper surface of the bottom plate 21a of the lower case 21. The cross member 24 is disposed alongside the energy storage cells 210 in the Y direction. Specifically, the cross member 24 is disposed between the energy storage stacks (101, 102, 103, 104) adjacent to each other in the Y direction. The cross member 24 extends in the X direction along the row of the energy storage cells 210 in each energy storage stack. The cross member 24 may be provided as a reinforcing member (framework member) for reinforcing the frame member 920 ( FIG. 1 ), for example. The cross member 24 is an example of a "parallel member" in the present disclosure.

[0081] The cross member 24 has a side surface 24a and a side surface 24b that face each other in the Y direction. That is, the side surface 24a and the side surface 24b are arranged in the Y direction. Each of the side surface 24a and the side surface 24b extends perpendicular to the Y direction. The side surface 24a is disposed on the side of the energy storage cell 210 relative to the side surface 24b. The side surface 24a and the side surface 24b are examples of the "first side surface" and the "second side surface" of the present disclosure, respectively.

[0082] The cross member 24 has a connecting surface 24e that connects an upper end 24c of the side surface 24a to an upper end 24d of the side surface 24b. The connecting surface 24e extends perpendicular to the Z direction. Note that the connecting surface 24e may connect portions below the upper ends 24c and 24d (corresponding to the "upper portion" in the present disclosure). The upper ends 24c and 24d are each an example of the "upper portion" in the present disclosure.

[0083] The cross member 24 has a hollow shape with an internal space S3 surrounded by the side surface 24a, the side surface 24b, the connecting surface 24e, and the bottom plate 21a of the lower case 21. The internal space S3 extends in the X direction.

[0084] A hole 24f is formed in the cross member 24. The hole 24f is a through-hole that penetrates the side surface 24a. Specifically, the hole 24f penetrates the side surface 24a in the Y direction. The hole 24f is an example of the "hole" and "through-hole" of the present disclosure.

[0085] The sheet member 330 includes a sagging portion 331 and an outer peripheral edge portion 332. The outer peripheral edge portion 332 surrounds the sagging portion 331. The outer peripheral edge portion 332 is fixed to the surface of the side surface 24a (the surface on the energy storage cell 210 side) by adhesive bonding, bolting, or the like. Note that the outer peripheral edge portion 332 may be attached to the surface of the side surface 24a opposite to the energy storage cell 210. The sheet member 330 is an example of a "heat-resistant member" of the present disclosure.

[0086] The sagging portion 331 is disposed at a position facing the pressure release valve SV. The sagging portion 331 covers the hole 24f from the Y1 side (the side of the energy storage cell 210). That is, the sagging portion 331 is provided at a position overlapping with the hole 24f when viewed from the Y1 side. Note that the direction in which the peaks and valleys of the sagging portion 331 are aligned (the Z direction in FIG. 15) is not limited to the example shown in FIG. 15.

[0087] This allows the sagging portions 331 to be deformed so as to protrude inward of the holes 24f, making it possible to easily reduce the momentum of the material discharged from the energy storage cells 210. Furthermore, since the holes 24f are through holes, it is possible to further prevent the sagging portions 331 from coming into contact with the cross members 24.

[0088] The slack portion 331 may have a notch 331c formed in the center in the Z direction, for example.

[0089] As shown in Fig. 16, a plurality of holes 24f are formed in the side surface 24a. The plurality of holes 24f are arranged side by side in the X direction. Gas discharged from the energy storage cell 210 (indicated by dashed arrows in Fig. 16) breaks the sagging portion 331 and flows into the internal space S3 through the hole 24f. The gas then passes through the internal space S3 and is guided to the exhaust valve 40 (Fig. 12). Note that the sheet member 330 (sagging portion 331) may extend in the X direction so as to cover the plurality of holes 24f.

[0090] In the second modified example, the side surface 24a is provided with the through-hole 24f, but the present disclosure is not limited to this. Instead of the through-hole, a recess may be formed in the side surface 24a.

[0091] Furthermore, in the second modified example described above, an example was shown in which the holes 24f were formed in the cross member 24, but the present disclosure is not limited to this. Holes or recesses (grooves) may be formed in a member other than the cross member 24 that is arranged alongside the energy storage cells 210 (for example, the peripheral wall 21d of the lower case (FIG. 5)).

[0092] [Second embodiment] Next, a second embodiment of the present disclosure will be described with reference to Figures 17 to 24. In the second embodiment, a power storage device 400 is mounted on a mobility robot.

[0093] 17, power storage device 400 is mounted on mobility robot 800. Mobility robot 800 is used to transport luggage and for a user to ride in. Note that the use of power storage device 400 is not limited to mobility robots.

[0094] Fig. 18 is a perspective view showing the configuration of power storage device 400. Power storage device 400 includes an arrangement member 401 in which power storage cells 410 (Fig. 19) are arranged. Arrangement member 401 includes a housing case 411, a top plate 420, a support plate 430, and four support columns 440. Power storage device 400 also includes a sheet member 450. Note that housing case 411 and sheet member 450 are examples of the "arrangement member" and "heat-resistant member" of the present disclosure, respectively.

[0095] The top plate 420 covers the storage case 411 from above (Z1 side). The support plate 430 supports the storage case 411 from below (Z2 side). The top plate 420 and the support plate 430 are arranged in the Z direction. The top plate 420 and the support plate 430 are made of metal (for example, aluminum).

[0096] Each of the four support columns 440 extends in the Z direction between the top plate 420 and the support plate 430. Each of the four support columns 440 is connected (for example, by fastening, welding, or bonding) to each of the top plate 420 and the support plate 430. The storage case 411 is disposed in an area surrounded by the four support columns 440. The support columns 440 are formed of, for example, aluminum.

[0097] Sheet member 450 covers storage case 411 from above and from the sides. Sheet member 450 is fixed (fastened or bonded) to top plate 420 and each support column 440. Sheet member 450 is heat resistant (flame retardant). Therefore, it is possible to prevent sheet member 450 from melting due to high-temperature gas discharged from power storage cell 410. Note that sheet member 450 may have heat insulating properties.

[0098] 19 is a cross-sectional view (cross-section perpendicular to the Z direction) showing the configuration of the power storage device 400. The sheet member 450 includes side surface portions 451 to 454. Each of the side surface portions 451 to 454 is fixed to a support 440.

[0099] The side surface portion 451 covers the accommodating case 411 from the X1 side. Between the side surface portion 451 and the accommodating case 411, a flow path 451a is formed through which gas flows.

[0100] Side surface portion 452 covers casing 411 from the X2 side. Side surface portion 451 and side surface portion 452 are arranged in the X direction. A flow path 452a through which gas flows is formed between side surface portion 452 and casing 411.

[0101] The side surface portion 453 covers the accommodating case 411 from the Y1 side. Between the side surface portion 453 and the accommodating case 411, a flow path 453a is formed through which gas flows.

[0102] The side surface portion 454 covers the casing 411 from the Y2 side. The side surface portion 453 and the side surface portion 454 are arranged in the Y direction. A flow path 454a through which gas flows is formed between the side surface portion 454 and the casing 411.

[0103] The flow paths 451a, 452a, 453a, and 454a are in communication with each other. Each of the flow paths 451a, 452a, 453a, and 454a is an example of the "exhaust duct" of the present disclosure.

[0104] As shown in Fig. 19, the side surface portion 453 has a sagging portion 453b. The sagging portion 453b is folded in an accordion-like shape when in a sagging state. Specifically, the sagging portion 453b is formed by arranging peaks and valleys alternately in the X direction when in a sagging state. At least a portion of the flow path 453a is formed by the sagging portion 453b. Note that the direction in which the peaks and valleys of the sagging portion 453b are arranged does not have to be limited to the example shown in Fig. 19.

[0105] The side surface portion 454 is provided with a sagging portion 454b. The sagging portion 454b is folded in an accordion-like shape when in a sagging state. Specifically, the sagging portion 454b is formed by arranging peaks and valleys alternately in the X direction. At least a portion of the flow path 454a is formed by the sagging portion 454b. Note that the direction in which the peaks and valleys of the sagging portion 454b are arranged does not have to be limited to the example shown in FIG. 19 .

[0106] The storage case 411 accommodates the power storage cell 410. Although Fig. 19 shows an example in which the number of power storage cells 410 is one, the number of power storage cells 410 may be two or more.

[0107] Figure 20 is a cross-sectional view taken along line XX-XX in Figure 19. Sheet member 450 includes an upper surface portion 455. Upper surface portion 455 is fixed to top plate 420. For example, an outer peripheral edge portion 455c of upper surface portion 455 may be fixed to top plate 420.

[0108] Top surface portion 455 covers casing 411 from the Z1 side. A flow path 455a through which gas flows is formed between top surface portion 455 and casing 411. Flow path 455a communicates with each of flow paths 451a, 452a, 453a, and 454a. Flow path 455a is an example of an "exhaust duct" in the present disclosure.

[0109] As shown in FIG. 20, the upper surface portion 455 is provided with sagging portions 455b. The sagging portions 455b are provided inside the outer peripheral edge portion 455c. The sagging portions 455b are folded in an accordion-like shape in the sagging state. The sagging portions 455b are formed by arranging peaks and valleys alternately in the X direction. At least a portion of the flow path 455a is formed by the sagging portions 455b. Note that the direction in which the peaks and valleys of the sagging portions 455b are arranged does not have to be limited to the example shown in FIG. 20.

[0110] The side surface portion 451 is provided with a sagging portion 451b. The sagging portion 451b is folded in an accordion-like shape when in a sagging state. The sagging portion 451b is formed by arranging peaks and valleys alternately in the Z direction. At least a portion of the flow path 451a is formed by the sagging portion 451b. Note that the direction in which the peaks and valleys of the sagging portion 451b are arranged is not limited to this example.

[0111] An upper end 451c of the side surface portion 451 is fixed to the support 440 adjacent to the side surface portion 451. A lower portion 451d near the lower end of the side surface portion 451 is fixed to the support 440 adjacent to the side surface portion 451. The sagging portion 451b is provided between the upper end 451c and the lower portion 451d.

[0112] The side surface portion 452 has a sagging portion 452b. The sagging portion 452b is folded in an accordion-like shape when in a sagging state. The sagging portion 452b is formed by arranging peaks and valleys alternately in the Z direction. At least a portion of the flow path 452a is formed by the sagging portion 452b. Note that the direction in which the peaks and valleys of the sagging portion 452b are arranged does not have to be limited to the example shown in FIG. 20.

[0113] An upper end 452c of the side surface portion 452 is fixed to the support 440 adjacent to the side surface portion 452. A lower portion 452d near the lower end of the side surface portion 452 is fixed to the support 440 adjacent to the side surface portion 452. The sagging portion 452b is provided between the upper end 452c and the lower portion 452d.

[0114] The energy storage cell 410 has a pressure release valve SV. The pressure release valve SV is provided on an upper surface 410a of the energy storage cell 410.

[0115] The housing case 411 has an exhaust valve 411a, which is provided on an upper surface 411b of the housing case 411.

[0116] Figure 21 is a cross-sectional view taken along line XXI-XXI in Figure 19. An upper end 453c of side surface portion 453 is fixed to support column 440 adjacent to side surface portion 453. A lower portion 453d near the lower end of side surface portion 453 is fixed to support column 440 adjacent to side surface portion 453. A sagging portion 453b (Figure 19) is provided between upper end portion 453c and lower portion 453d.

[0117] An upper end 454c of the side surface portion 454 is fixed to the support 440 adjacent to the side surface portion 454. A lower portion 454d near the lower end of the side surface portion 454 is fixed to the support 440 adjacent to the side surface portion 454. A sagging portion 454b (FIG. 19) is provided between the upper end 454c and the lower portion 454d.

[0118] Fig. 22 is a diagram showing a state when energy storage cell 410 discharges discharged materials such as high-temperature gas from the state shown in Fig. 19. As shown in Fig. 22, the sagging portions (451b to 454b) (Figs. 19 and 20) of side surface portions 451 to 454 have changed to a shape that protrudes on the side opposite to casing 411. This increases the flow path area of ​​each flow path (451a to 454a).

[0119] Figure 23 is a cross-sectional view taken along line XXIII-XXIII in Figure 22. As shown in Figure 23, when an upward force is applied to upper surface portion 455, upper surface portion 455 is deformed by the force of the discharge of the waste, and upper surface portion 455 and top plate 420 come into close contact with each other.

[0120] This increases the flow path area of ​​flow path 455a. In Fig. 23, the flow path of the high-temperature gas discharged from pressure release valve SV is indicated by dashed arrows. The high-temperature gas passes through each flow path (451a to 455a) and is discharged to the outside from the lower end of sheet member 450. Thereafter, although not shown in detail, the high-temperature gas is discharged below (toward the ground) mobility robot 800 (Fig. 17).

[0121] Fig. 24 is a cross-sectional view taken along line XXIV-XXIV in Fig. 22. In Fig. 24, the flow path of the high-temperature gas discharged from the pressure release valve SV (Fig. 23) is indicated by dashed arrows.

[0122] The size of the bellows (width between the peaks and valleys and height difference) in the sagging portions (451b to 455b) is set, for example, so that the volume (total volume of each flow path) of the flow paths (451a to 455a) when the sagging portions are taut (FIGS. 22 to 24) is 105% to 150% of the volume of the flow paths when the sagging portions are slack (FIGS. 19 to 21). Also, as in the first embodiment, the length of the sagging portions when taut (length in the direction in which the peaks and valleys are aligned) may be 105% to 150% of the length in the slack state.

[0123] As described above, in the second embodiment, sheet member 450 having sagging portions (451b-455b) covers the upper and side surfaces of casing 411. As a result, when high-temperature gas or the like is discharged from power storage cell 410, the sagging portions are deformed, thereby expanding flow paths (451a-455a). As a result, the momentum (flow velocity) of the high-temperature gas or the like can be reduced. This allows the high-temperature gas or the like with reduced momentum to be discharged to the outside, and also prevents the high-temperature gas or the like from leaking through gaps in sheet member 450.

[0124] [Variations] In the first embodiment, the sagging portion 31 covers the smoke exhaust hole 21e, which is a through-hole formed in the lower case 21, but the present disclosure is not limited to this. For example, the sagging portion may cover a recess (groove) formed in the lower case.

[0125] In the first embodiment, the sagging portion 31 has the notch 31c formed therein, which serves as the starting point for fracture. However, the present disclosure is not limited to this. For example, a portion of the sagging portion may be formed to be thinner than the other portions. Also, a portion of the sagging portion may be formed from a material with lower rigidity than the other portions.

[0126] In the first embodiment described above, an example was shown in which the sagging portion 131 is provided at a position facing the exhaust valve 40, but the present disclosure is not limited to this. For example, the sagging portion may be provided at a position facing the hole 21j (FIG. 12) formed in the lower case 21. Alternatively, the sagging portion may be provided between the hole 21j and the exhaust valve 40.

[0127] In the second embodiment, an example has been described in which the energy storage cells 410 are housed in the housing case 411, but the present disclosure is not limited to this. The energy storage cells 410 may not be housed in a housing case, but may be directly disposed (placed) on the support plate 430.

[0128] In the first and second embodiments, examples have been shown in which the sagging portion is folded in an accordion-like manner, but the present disclosure is not limited thereto. For example, as shown in FIG. 25, the sagging portion 510 formed in the sheet member 500 may hang downward due to its own weight in the sagging state. The sagging portion 510 may be folded and stored in a predetermined space (for example, like an airbag). The sheet member 500 is an example of the "heat-resistant member" of the present disclosure.

[0129] In the first embodiment described above, an example was shown in which the sheet member 130 that covers the exhaust valve 40 is provided, but the present disclosure is not limited to this. The sheet member 130 may not be provided. Furthermore, the sheet member 130 may be provided, but the sheet member 30 may not be provided. In this case, a heat-resistant sheet that does not have a sagging portion may be used instead of the sheet member 30.

[0130] In the first embodiment described above, an example was shown in which the length L2 of slack portion 31 in the slack-removed (tensioned / stretched) state is 105% to 150% of the length L1 of slack portion 31 in the slack state, but the present disclosure is not limited to this. For example, the area of ​​slack portion 31 in the slack-removed state may be, for example, 105% to 150% of the area of ​​slack portion 31 in the slack state.

[0131] The configurations of the above-described embodiment and the various modified examples may be combined with each other.

[0132] 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]

[0133] 10,110,210,410 Energy storage cell, 20 Housing (arrangement member) (storage case), 21a Bottom plate (lower cover), 21e Smoke exhaust hole (hole) (through hole), 22 Upper cover, 22a Lower surface, 22b Recess, 24 Cross member (parallel member), 24a Side (first side), 24b Side (second side), 24c Upper end (upper part of first side), 24d Upper end (upper part of second side), 24e Connection surface, 24f Hole (hole) (through hole), 30,130,230,330,450,500 Sheet member (heat-resistant member), 31,131,231,331,451b,452b,453b,454b,455b,510 Sagging portion, 31a Weak portion 31a (second portion), 31b non-weak portion (first portion), 40, 411a exhaust valve, 100, 400 power storage device, 411 storage case (positioning member), 451a, 452a, 453a, 454a, 455a flow path (exhaust duct), L1 length (length in slack state), L2 length (length in extended state), S1 cell space (first space), S2 smoke exhaust space (second space), S3 internal space, SV pressure release valve.

Claims

1. a storage cell provided with a pressure release valve; an arrangement member on which the storage cells are arranged; a heat-resistant member provided on the placement member, The heat-resistant member includes a slack portion that is arranged in a slack state.

2. The power storage device according to claim 1 , wherein the slack portion is disposed at a position facing the pressure release valve.

3. the arrangement member includes an upper cover arranged above the energy storage cell, the upper cover has a lower surface, An upwardly recessed recess is formed on the lower surface, The power storage device according to claim 2 , wherein the sagging portion covers the recess from below.

4. the arrangement member includes a lower cover arranged below the energy storage cell, A hole is formed in the lower cover, The power storage device according to claim 2 , wherein the sagging portion covers the hole from above.

5. The power storage device according to claim 4 , wherein the hole portion includes a through-hole that penetrates the lower cover.

6. the arrangement member includes a parallel member that is arranged alongside the energy storage cell in an intersecting direction that intersects with the up-down direction, The parallel members have holes formed therein, The power storage device according to claim 2 , wherein the sagging portion covers the hole from one side in the intersecting direction.

7. The parallel members are a first side surface and a second side surface opposed to each other in the intersecting direction; a connecting surface connecting upper portions of the first side surface and the second side surface, The connector has a hollow shape in which an internal space is formed surrounded by the first side surface, the second side surface, and the connecting surface, the first side surface is disposed on the storage cell side with respect to the second side surface, The power storage device according to claim 6 , wherein the hole includes a through-hole that penetrates the first side surface.

8. 8. The power storage device according to claim 1, wherein the sagging portion has a first portion and a second portion that is more easily broken than the first portion.

9. 8. The power storage device according to claim 1, wherein the length of the slack portion in the extended state is 105% to 150% of the length of the slack portion in the slack state.

10. the sagging portion deforms to protrude toward the energy storage cell when a pressure in a first space on the energy storage cell side with respect to the sagging portion is lower than a pressure in a second space on an opposite side to the first space with respect to the sagging portion, The electricity storage device according to any one of claims 1 to 7, wherein the sagging portion that protrudes toward the electricity storage cell is spaced apart from the electricity storage cell without contacting the electricity storage cell.

11. the arrangement member includes a housing case that houses the power storage cell, the housing case has an exhaust valve; The power storage device according to claim 1 , wherein the slack portion is formed at a position facing the exhaust valve.

12. an exhaust duct through which gas discharged from the exhaust valve flows; The power storage device according to claim 11 , wherein at least a portion of the exhaust duct is defined by the sagging portion.

13. 8. The power storage device according to claim 1, wherein the slack portion is folded in an accordion-like shape when in the slack state.

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