Energy storage device

Abstract

The present invention provides an energy storage device that eliminates the need for waterproofing the detection sensor that detects gas discharged downward from the energy storage cell. [Solution] The energy storage device 100 includes a plurality of energy storage cells 10 including a lower surface 6 on which a safety valve SV is provided, a housing 30 that houses the plurality of energy storage cells 10, a smoke exhaust sensor 50 that detects gas discharged from the plurality of energy storage cells, and a detection space forming member 40 that forms a detection space S2 in which the gas is detected by the smoke exhaust sensor 50. The housing 30 includes a lower case 31 including a bottom plate 31c and a shear panel 33 that forms a smoke exhaust space S1 between the bottom plate 31c of the lower case 31 and the plurality of energy storage cells 10, and is provided so that the detection space S2 is separated from the smoke exhaust space S1.

Description

Technical Field

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

Background Art

[0002] Japanese Patent Publication No. 2022-525014 (Patent Document 1) discloses a power battery pack mounted on an electric vehicle. The power battery pack includes a plurality of single cells. Each of the plurality of single cells is provided with an explosion-proof valve for discharging internal smoke or gas.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Although not described in the above Patent Document 1, when discharging smoke or gas from the lower surface of a single cell (power storage cell) by providing an explosion-proof valve (safety valve) on the lower surface of the single cell, a smoke exhaust space (smoke exhaust path) is formed below the single cell. It is conceivable to arrange a smoke exhaust sensor (detection sensor) for detecting gas (smoke) in the smoke exhaust space. In this case, for example, in order to suppress the influence of water on the smoke exhaust sensor during flooding or the like, it is necessary to perform waterproof treatment on the smoke exhaust sensor.

[0005] This disclosure has been made to solve the above problems, and an object thereof is to provide a power storage device capable of omitting waterproof treatment for a detection sensor that detects gas discharged downward from a power storage cell.

Means for Solving the Problems

[0006] An energy storage device according to one aspect of the present disclosure comprises at least one energy storage cell including a lower surface on which a safety valve is provided; a housing for housing at least one energy storage cell; a detection sensor for detecting gas discharged from at least one energy storage cell; and a detection space forming member that forms a detection space in which the gas is detected by the detection sensor. The housing includes a lower case which is arranged to cover at least one energy storage cell from below and includes a bottom surface with a through hole formed at a position overlapping the safety valve; and a shear panel which is arranged below the lower case and forms a smoke exhaust space between itself and the bottom surface of the lower case. The detection space forming member is provided to form a detection space between the bottom surface of the lower case and at least one energy storage cell, and to separate the detection space from the smoke exhaust space.

[0007] In an energy storage device according to one aspect of this disclosure, as described above, the detection space forming member is provided to form a detection space between the bottom surface of the lower case and at least one energy storage cell, and to separate the detection space from the smoke exhaust space. As a result, even if water enters the smoke exhaust space, it is possible to suppress the entry of water into the detection space which is separated from the smoke exhaust space. Consequently, it is possible to suppress the effect of water on the detection sensor that detects gas in the detection space. This makes it possible to omit waterproofing treatment for the detection sensor.

[0008] At least one energy storage cell may include multiple energy storage cells arranged in the direction of the arrangement. The sensing space forming member may extend along the arrangement direction along the multiple energy storage cells. This configuration allows gases emitted from each of the multiple energy storage cells to easily flow into the sensing space.

[0009] The energy storage device may be equipped with a waterproof seal that closes the through-hole formed in the bottom surface of the lower case. This configuration can further suppress the intrusion of water from the smoke exhaust space into the detection space through the through-hole.

[0010] The detection space forming member may be formed to deform from a standard shape to a bulging shape that bulges downward relative to the standard shape when the pressure in the detection space increases. With such a configuration, the vertical height of the detection space forming member when it has the standard shape can be made smaller than the vertical height of the detection space forming member when it has the bulging shape. As a result, the height of the energy storage device (standard height) when it has the standard shape with no (or little) gas discharge from the energy storage cell can be made relatively small.

[0011] The detection space forming member in the standard shape may have a first portion provided at a position facing the safety valve of at least one energy storage cell, and a second portion positioned adjacent to the first portion in an intersecting direction that intersects the vertical direction, and formed to be recessed downward from the first portion. With this configuration, the first portion is positioned relatively closer to the safety valve than the second portion, so the influence of gas pressure on the first portion can be increased compared to the case where the distance between each of the first and second portions and the safety valve is equal. As a result, the first portion can be easily pushed downward by the gas pressure, so the detection space forming member can be easily made to bulge downward.

[0012] The energy storage device may include a waterproof sealing member positioned between the bottom surface of the lower case and the detection space forming member, so as to surround the through-hole. This configuration further suppresses water from entering the detection space from the smoke exhaust space through the through-hole.

[0013] The energy storage device may include a heat-resistant plate positioned on the part of the shear panel facing the through-hole formed on the bottom surface of the lower case. This configuration can suppress the scattering (adhesion) of blast (sparks) released from the safety valve and passing through the through-hole onto the shear panel. [Effects of the Invention]

[0014] According to this disclosure, waterproofing treatment for the detection sensor that detects gas discharged downward from the energy storage cell can be omitted.

Brief Description of the Drawings

[0015] [Figure 1] It is a diagram schematically showing a vehicle equipped with a power storage device according to an embodiment. [Figure 2] It is a perspective view showing a power storage device and a vehicle body according to an embodiment. [Figure 3] It is a cross-sectional view taken along line III-III of FIG. 2. [Figure 4] It is a perspective view showing the configuration of a power storage cell. [Figure 5] It is a perspective view showing the configuration of a lower case of the power storage device. [Figure 6] It is a perspective view showing the configuration of a lower case to which a bracket unit is attached. [Figure 7] It is an exploded perspective view showing the configuration of a lower case and a cooler. [Figure 8] It is an exploded perspective view showing the configuration of a lower case and an inner path defining portion. [Figure 9] [[ID=3l]]It is an exploded perspective view showing the configuration of a lower case, a collection unit, and a shared panel. [Figure 10] It is a plan view of the lower case seen from below. [Figure 11] It is a cross-sectional view taken along line XI-XI of FIG. 10. [Figure 12] It is a partially enlarged view of a detection space forming member having a reference shape. [Figure 13] It is a partially enlarged view of a detection space forming member having a bulging shape. [Figure 14] It is a partially enlarged view of a broken detection space forming member. [Figure 15] It is a partially enlarged view near the side collection portion of FIG. 11.

Modes for Carrying Out the Invention

[0016] Embodiments of the present disclosure will be described with reference to the drawings. In the drawings referred to below, the same or corresponding members are denoted by the same reference numerals.

[0017] A power storage device 100 in one embodiment of the present disclosure will be described with reference to Figures 1 to 15. Figure 1 is a schematic side view showing a vehicle 900 equipped with the power storage device 100 according to this embodiment. In this specification, the X, Y, and Z directions are mutually orthogonal directions. For example, the X and Y directions are the longitudinal and longitudinal directions and the vehicle width direction of the vehicle 900 when the power storage device 100 is mounted on the vehicle 900, respectively. The X1 and X2 directions are the front and rear of the vehicle, respectively. The Y1 and Y2 directions are the left and right sides of the vehicle, respectively. The Z direction is the vertical direction. In this disclosure, the X and Y directions are examples of the "arrangement direction" and "intersecting direction," respectively.

[0018] As shown in Figure 1, the vehicle 900 includes a vehicle body 910 and an equipment unit 930 in addition to the energy storage device 100. Examples of the vehicle 900 include a hybrid electric vehicle, a plug-in hybrid electric vehicle, and a battery electric vehicle. The vehicle body 910 includes a frame member 920. The frame member 920 is located at the bottom of the vehicle body 910.

[0019] As shown in Figure 2, the frame member 920 includes a pair of first frames 921, a pair of second frames 922, a first cross frame 923, and a second cross frame 924.

[0020] The pair of first frames 921 face each other in the X direction. Each first frame 921 has a shape that extends along the Y direction.

[0021] The pair of second frames 922 face each other in the Y direction. Each second frame 922 has a shape that extends along the X direction. The ends of each second frame 922 in the X direction are connected to the first frame 921. Together with the pair of first frames 921, the pair of second frames 922 form a roughly rectangular tubular frame that surrounds the energy storage device 100.

[0022] The first cross frame 923 is positioned between a pair of first frames 921 and connects a pair of second frames 922 to each other.

[0023] The second cross frame 924 is positioned between a pair of first frames 921 and connects a pair of second frames 922 to each other. 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 sheet cloth.

[0024] The energy storage device 100 is attached to the frame member 920. The energy storage device 100 is located below the first cross frame 923 and the second cross frame 924. The energy storage device 100 comprises four energy storage stacks 101 to 104. However, the number of energy storage stacks is not limited to four.

[0025] In this embodiment, each energy storage stack 101-104 is formed in the shape of a rectangular parallelepiped, elongated in the X direction. As shown in Figure 2, the four energy storage stacks 101-104 are arranged to be aligned along the Y direction.

[0026] Figure 3 is a cross-sectional view along line III-III in Figure 2. As shown in Figure 3, the energy storage device 100 comprises an energy storage cell 10, a cooler 20, a housing 30, and a reinforcing member 35. At least one energy storage cell 10 is included in each energy storage stack 101-104 (Figure 2). In this embodiment, multiple (e.g., 50) energy storage cells 10 are arranged in the X direction in each energy storage stack 101-104. In Figure 3, the discharge direction of the gas discharged from the safety valve SV (described later) is indicated by a dashed-dotted arrow.

[0027] Each energy storage cell 10 includes an electrode body 11. The electrode body 11 may be composed of a wound body in which a positive electrode sheet and a negative electrode sheet are wound with a separator in between, or it may be composed of a laminate in which a positive electrode sheet and a negative electrode sheet are stacked with a separator in between. The electrode body 11 is formed in a shape that is elongated in the Y direction.

[0028] The cooler 20 cools multiple energy storage cells 10. In this embodiment, the cooler 20 cools each of the energy storage stacks 101 to 104. A cooling medium (such as oil) flows through the cooler 20.

[0029] The enclosure 30 includes a lower case 31, an upper cover 32, and a share panel 33.

[0030] The upper cover 32, together with the lower case 31, houses a plurality of energy storage cells 10. In this embodiment, the upper cover 32, together with the lower case 31, houses four energy storage stacks 101 to 104 (Figure 2) in a sealed state. The upper cover 32 is positioned to cover each energy storage stack 101 to 104 from above. The lower case 31 is positioned to cover each energy storage stack 101 to 104 from below. The peripheral edge of the upper cover 32 is connected to the peripheral edge of the lower case 31 by bolts or the like via a sealing member.

[0031] The shear panel 33 is located below the lower case 31. The shear panel 33 has the function of protecting the lower case 31. The shear panel 33 may be formed in a flat plate shape.

[0032] The bottom plate 31c and share panel 33 of the lower case 31 are located below the multiple energy storage cells 10. A smoke exhaust space S1 is formed between the bottom plate 31c and the share panel 33. The smoke exhaust space S1 constitutes a smoke exhaust path through which gas (smoke) (hereinafter simply referred to as "gas") discharged from the energy storage cells 10 flows. The gas in the smoke exhaust space S1 is discharged to the outside through the opening 33c described later. The bottom plate 31c is an example of the "bottom surface" in this disclosure.

[0033] The energy storage device 100 includes a smoke exhaust sensor 50 that detects the gas emitted from each of the multiple energy storage cells 10. The smoke exhaust sensor 50 is an example of a "detection sensor" as described herein.

[0034] In conventional energy storage devices, smoke exhaust sensors are located in the smoke exhaust space. Therefore, it is necessary to waterproof the smoke exhaust sensors to suppress the effects of water on them, for example, during flooding.

[0035] In this embodiment, the energy storage device 100 includes a detection space forming member 40 that forms a detection space S2 in which gas discharged from each of the plurality of energy storage cells 10 is detected. The detection space forming member 40 is positioned between the bottom plate 31c of the lower case 31 and the plurality of energy storage cells 10. As a result, the detection space S2 is formed between the bottom plate 31c of the lower case 31 and the plurality of energy storage cells 10. The detection space forming member 40 is provided so as to separate the detection space S2 from the exhaust space S1. The detection space forming member 40 (detection space S2) is provided below each energy storage stack (101 to 104).

[0036] The detection space forming member 40 is formed so as to be open on the upper side. The detection space forming member 40 is formed to extend in the X direction so as to span across a plurality of energy storage cells 10 arranged in the X direction. The plurality of energy storage cells 10 are arranged such that a plurality of safety valves SV are arranged in the X direction. The detection space forming member 40 is provided so as to cover the plurality of safety valves SV arranged in the X direction from below.

[0037] Multiple energy storage cells 10 are arranged to cover (lid) the upper open end of the detection space forming member 40. As a result, a detection space S2 is formed between the multiple energy storage cells 10 and the detection space forming member 40. Gas discharged downward (towards the detection space S2) from the energy storage cells 10 flows into the detection space S2 and flows within the detection space S2 in the X direction.

[0038] Furthermore, the smoke exhaust sensor 50 is provided in the detection space S2. Therefore, the gas flowing through the detection space S2 is detected by the smoke exhaust sensor 50. The smoke exhaust sensor 50 is positioned at the X1 and X2 ends of the detection space S2 (detection space forming member 40) in the X direction. The smoke exhaust sensor 50 may also be attached to the inner surface (the surface on the detection space S2 side) of the detection space forming member 40.

[0039] The smoke exhaust sensor 50 is installed in each detection space S2. This makes it possible to individually detect smoke exhaust for each energy storage stack 101 to 104 using the smoke exhaust sensor 50.

[0040] The detection space forming member 40 is made of a material that ruptures with heat. For example, the detection space forming member 40 is made of a thin film of metal. As a result, the detection space forming member 40 ruptures as its temperature rises while gas flows through the detection space S2. Consequently, the gas flowing through the detection space S2 flows into the exhaust gas space S1 through the rupture point of the detection space forming member 40. This makes it possible to detect the gas with the exhaust gas sensor 50 within a certain time after the gas is discharged from the energy storage cell 10, and then move the gas from the detection space S2 to the exhaust gas space S1 as the detection space forming member 40 ruptures.

[0041] On both sides of the multiple energy storage cells 10 in the X direction, a pair of end plates 10a are provided to sandwich the multiple energy storage cells 10 from both sides in the X direction. A monitoring unit (Smart Battery Management) 10b is positioned outside each end plate 10a in the X direction.

[0042] The equipment unit 930 is located, for example, at the end in the X direction. In this embodiment, the equipment unit 930 is located on the rear of the upper cover 32 in the longitudinal direction of the vehicle 900. The equipment unit 930 includes a junction box 931, an Electricity Supply Unit 932, an Electronic Control Unit 933, a first cooler 934, a second cooler 935, and an equipment cover 936.

[0043] The junction box 931 is located above the upper cover 32. The junction box 931 houses relays, fuses, and the like. The junction box 931 is cooled by a first cooler 934 located between the junction box 931 and the upper cover 32.

[0044] The power supply unit 932 is located above the junction box 931. The power supply unit 932 is cooled by a second cooler 935 located on top of the power supply unit 932. The electronic control unit 933 is located above the junction box 931.

[0045] The equipment cover 936 houses the junction box 931, the power supply unit 932, the electronic control unit 933, and the second cooler 935.

[0046] The reinforcing member 35 is positioned on the upper cover 32. The reinforcing member 35 has the function of distributing the load that acts locally from above on the energy storage device 100 from the occupants of the vehicle 900.

[0047] Figure 4 is a perspective view showing the configuration of the energy storage cell 10. As shown in Figure 4, each energy storage cell 10 has a cell case 12, a pair of external terminals 13, and a safety valve SV. The cell case 12 houses the electrode body 11 (Figure 3).

[0048] The cell case 12 is formed in the shape of a rectangular parallelepiped. 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, the width W1 of the energy storage cell 10 in the Y direction is greater than the width W2 of the energy storage cell 10 in the X direction. The height H1 of the energy storage cell 10 is less than the width W1 and greater than the width W2.

[0049] The energy storage cell 10 (cell case 12) has a short side 1, a short side 2, a long side 3, a long side 4, a top surface 5, and a bottom surface 6.

[0050] Short side 1 and short side 2 are arranged in the Y direction. Specifically, short side 1 and short side 2 are one end face and the other end face of the energy storage cell 10 in the Y direction, respectively.

[0051] Long sides 3 and 4 are arranged in the X direction. Specifically, long sides 3 and 4 are one end face and the other end face of the energy storage cell 10 in the X direction, respectively.

[0052] 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 Z1-side end face and the Z2-side end face of the energy storage cell 10, respectively.

[0053] A pair of external terminals 13 are provided on the short side 1 and short side 2, respectively. The safety valve SV is provided on the bottom surface 6. The safety valve SV opens when the pressure of smoke or gas inside the cell case 12 exceeds a certain level. In other words, the bottom surface 6 on which the safety valve SV is provided constitutes the pressure release surface of the cell case 12.

[0054] Figure 5 is a perspective view showing the configuration of the lower case 31. The lower case 31 includes a housing section 31a and a plate section 31b. The housing section 31a includes a bottom plate 31c and a peripheral wall 31d. The bottom plate 31c is formed in a plate shape, and a plurality of smoke exhaust holes 31e are formed in the bottom plate 31c. The plurality of smoke exhaust holes 31e are arranged in the longitudinal direction (X direction) of the vehicle 900. In addition, multiple rows of the plurality of smoke exhaust holes 31e arranged in the X direction are arranged in the Y direction (four in Figure 5). The rows of the plurality of smoke exhaust holes 31e arranged in the X direction are formed below each of the energy storage stacks 101 to 104 (Figure 2). Note that the smoke exhaust holes 31e are an example of a "through hole" in this disclosure.

[0055] Alternatively, instead of the multiple smoke exhaust holes 31e arranged in the X direction, an elongated opening in the X direction may be formed. In such an opening, with the lower case 31 fixed to the upper cover 32, each safety valve SV of the multiple energy storage cells 10 communicates with the opening. By using such an opening, it is possible to easily align the opening with the safety valve SV.

[0056] The peripheral wall 31d is formed to extend upward from the outer peripheral edge of the bottom plate 31c. The peripheral wall 31d is formed in an annular shape. The peripheral wall 31d includes a front wall 31f located at the front (X1 side), a rear wall 31g located at the rear (X2 side), a left side wall 31h located at the left side (Y1 side), and a right side wall 31i located at the right side (Y2 side). The housing section 31a has an opening that opens upward. The plate section 31b is formed to protrude horizontally from the opening edge of the housing section 31a.

[0057] Here, multiple energy storage cells 10 are arranged in the housing section 31a. The safety valves SV (Figure 4) and smoke exhaust holes 31e of the energy storage cells 10 are arranged in the Z direction, and the safety valves SV and smoke exhaust holes 31e are in communication with each other.

[0058] As shown in Figure 6, the energy storage device 100 includes a bracket unit 60 provided on the outer circumferential surface of the housing section 31a. The bracket unit 60 is provided on the outer surface of the peripheral wall 31d of the lower case 31. The bracket unit 60 includes a front bracket 61, a rear bracket 62, a rear bracket 63, a side bracket 64, and a side bracket 65.

[0059] The front bracket 61 is fixed to the outer surface of the front wall 31f of the lower case 31. The rear brackets 62 and 63 are each provided on the outer surface of the rear wall 31g. The rear brackets 62 and 63 are spaced apart in the Y direction. A gap 66 is formed between the rear brackets 62 and 63. The gap 66 is located in the center of the rear wall 31g in the Y direction.

[0060] Side bracket 64 is provided on the outer surface of the left wall 31h. Side bracket 65 is provided on the outer surface of the right wall 31i.

[0061] The bracket unit 60 is formed in a substantially annular shape, and a gap 66 is formed on the rear side (X2 side) in the X direction.

[0062] Figure 7 is a perspective view showing the lower case 31, the bracket unit 60, and the cooler 20. The cooler 20 includes a cooling section 21, a connecting section 22, and a connecting section 23.

[0063] The cooling section 21 is formed to extend in the X direction. The connecting section 22 is provided at the front end (X1 side end) of the cooling section 21, and the connecting section 23 is provided at the rear end (X2 side end) of the cooling section 21.

[0064] A supply pipe and a discharge pipe (not shown) are connected to the connection section 22. Coolant is supplied from the supply pipe. The coolant passes through the inside of the cooling section 21 and the connection section 22 and returns to the connection section 22. The coolant that returns to the connection section 22 is discharged from the discharge pipe.

[0065] Above the cooling unit 21, with the bottom plate 31c of the lower case 31 in between, are the energy storage stacks 101 to 104 (Figure 2). The cooling unit 21 includes a first cooling unit 24, a second cooling unit 25, a third cooling unit 26, and a fourth cooling unit 27. The first cooling unit 24, the second cooling unit 25, the third cooling unit 26, and the fourth cooling unit 27 are arranged in this order from the Y2 side (in the Y direction).

[0066] The first cooling section 24 has a flow section 24A, a flow section 24B, and a connecting plate 24C. The second cooling section 25 has a flow section 25A, a flow section 25B, and a connecting plate 25C. The third cooling section 26 has a flow section 26A, a flow section 26B, and a connecting plate 26C. The fourth cooling section 27 has a flow section 27A, a flow section 27B, and a connecting plate 27C. Since the first cooling section 24, the second cooling section 25, the third cooling section 26, and the fourth cooling section 27 have the same configuration as each other, only the first cooling section 24 will be described in detail as a representative example.

[0067] The flow sections 24A and 24B are arranged with a gap between them in the Y direction. Each of the flow sections 24A and 24B is formed to extend in the X direction.

[0068] The connecting plate 24C is positioned between the flow section 24A and the flow section 24B, and is provided to connect the flow section 24A and the flow section 24B.

[0069] Multiple holes 28 are formed in the connecting plate 24C. The multiple holes 28 are spaced apart in the X direction.

[0070] Each hole 28 corresponds to each exhaust hole 31e formed in the bottom plate 31c. When the cooler 20 is fixed to the lower case 31, the holes 28 and exhaust holes 31e are arranged in the Z direction.

[0071] Alternatively, instead of the multiple holes 28 arranged in the X direction, an elongated opening in the X direction may be formed. In such an opening, when the cooler 20 is fixed to the lower case 31, the exhaust hole 31e formed in the lower case 31 communicates with the opening. By using such an opening, it is possible to easily align the opening and the exhaust hole 31e.

[0072] The cooler 20 is fixed to the bottom plate 31c of the lower case 31. Specifically, the cooler 20 is fixed to the bottom plate 31c with a thermal conductive adhesive, which is not shown in Figure 7.

[0073] As shown in Figure 8, the energy storage device 100 includes an internal path defining section 70. The internal path defining section 70 is located on the lower surface of the cooler 20.

[0074] The inner path regulating section 70 is located in the smoke exhaust space S1 (Figure 3) between the share panel 33 and the bottom plate 31c of the lower case 31, and is formed in an annular shape.

[0075] The inner path defining section 70 includes a front side section 71, a rear side section 72, a left side section 73, and a right side section 74. The front side section 71 and the rear side section 72 are spaced apart from each other in the X direction. Each of the front side section 71 and the rear side section 72 extends in the Y direction. The left side section 73 and the right side section 74 are spaced apart from each other in the Y direction. Each of the left side section 73 and the right side section 74 extends in the X direction.

[0076] An opening 75 is formed between the front edge 71 and the left edge 73. An opening 76 is formed between the front edge 71 and the right edge 74. An opening 77 is formed between the rear edge 72 and the left edge 73. An opening 78 is formed between the rear edge 72 and the right edge 74.

[0077] The front portion 71 is located on the front side (X1 side) of the inner path defining portion 70. The front portion 71 is positioned on the lower surface of the connection portion 22 of the cooler 20.

[0078] The rear edge portion 72 is located on the rear side (X2 side) of the inner path defining portion 70. The rear edge portion 72 is positioned on the lower surface of the connection portion 23 of the cooler 20.

[0079] The left-hand portion 73 is positioned between the left end of the front portion 71 (the end on the Y1 side) and the left end of the rear portion 72 (the end on the Y2 side). The left-hand portion 73 is positioned in the flow portion 27B.

[0080] The right-hand side portion 74 is positioned between the right end of the front side portion 71 (the end on the Y2 side) and the right end of the rear side portion 72 (the end on the Y2 side). The right-hand side portion 74 is positioned in the flow portion 24A.

[0081] As shown in Figure 9, the energy storage device 100 includes a collection unit 80. The collection unit 80 includes a front collection section 81, a rear collection section 82, a side collection section 83, and a side collection section 84.

[0082] The front collection unit 81 is fixed to the front bracket 61 and is positioned adjacent to the front edge unit 71.

[0083] The rear collection section 82 is fixed to the rear brackets 62 and 63 respectively and is positioned adjacent to the rear edge section 72.

[0084] The side collection unit 83 is fixed to the side bracket 64 and is positioned adjacent to the left side unit 73. The side collection unit 84 is fixed to the side bracket 65 and is positioned adjacent to the right side unit 74.

[0085] The collection unit 80 is fixed in an annular shape to a bracket unit 60, which is formed annularly together with the shear panel 33, by a plurality of bolts 85.

[0086] In this way, the share panel 33 is fixed to the bracket unit 60 in an annular shape. As a result, the share panel 33 comes into annular contact with the bracket unit 60 or the collection unit 80.

[0087] The shear panel 33 includes a main body 33a and a flange 33b formed on the outer peripheral edge of the main body 33a. The main body 33a is formed to be recessed downward from the flange 33b. The flange 33b is formed to extend horizontally from the edge of the main body 33a. In the example shown in this figure, an opening 33c is formed in the main body 33a. The opening 33c is formed in the rear portion of the main body 33a. The main body 33a includes a bottom plate 33d and a peripheral wall 33e. The bottom plate 33d is located on the lower surface of the shear panel 33. The peripheral wall 33e is formed to rise from the outer peripheral edge of the bottom plate 33d and connects the bottom plate 33d and the flange 33b. The peripheral wall 33e includes a front wall 33f located at the front, a rear wall 33g located at the rear, a left side wall 33h, and a right side wall 33i. The opening 33c is formed in the rear wall 33g.

[0088] Figure 10 is a bottom view showing the cooler 20, the bracket unit 60, and the inner path regulating section 70. In Figure 10, the collection unit 80 is represented by a dashed line. In Figure 10, region R1 indicates the area of ​​the bottom plate 31c of the lower case 31 in which the exhaust holes 31e (holes 28) are formed. Contact region R2 indicates the area in contact between the collection unit 80 and the bracket unit 60. In Figure 10, hatching is used to clearly indicate the contact region R2. Contact region R2 is located outside the inner path regulating section 70. Contact region R2 is formed to surround the inner path regulating section 70.

[0089] In the contact area R2, the collection unit 80 comes into contact with the bracket unit 60, forming an outer path defining portion 90. That is, the outer path defining portion 90 is located outside the inner path defining portion 70 (71-74) and is formed to surround the inner path defining portion 70. The outer path defining portion 90 is a sealing portion formed by fastening the collection unit 80 and the bracket unit 60 together. This prevents gases from the energy storage cell 10 from passing through the outer path defining portion 90 and leaking to the outside of the energy storage device 100.

[0090] The outer path defining section 90 includes a front edge section 91, a rear edge section 92, a rear edge section 93, a side edge section 94, and a side edge section 95.

[0091] The front portion 91 is located on the front bracket 61. The rear portions 92 and 93 are located on the rear bracket 62 and rear bracket 63, respectively. Similarly, the side portions 94 and 95 are located on the side bracket 64 and side bracket 65, respectively.

[0092] An opening 96 is formed in the outer path defining portion 90. The opening 96 is formed between the rear edge portion 92 and the rear edge portion 93. The opening 96 is provided at a position corresponding to the gap 66 of the bracket unit 60.

[0093] An exhaust passage 110 is formed between the inner path defining section 70 and the outer path defining section 90, which are configured as described above.

[0094] The exhaust passage 110 includes a front passage 111, a rear passage 112, a rear passage 113, a side passage 114, and a side passage 115.

[0095] The front aisle 111 is located between the front edge 71 and the front edge 91. The rear aisle 112 is located between the rear edge 72 and the rear edge 92. The rear aisle 113 is located between the rear edge 72 and the rear edge 93. The side aisle 114 is located between the left edge 73 and the side edge 94. The side aisle 115 is located between the right edge 74 and the side edge 95.

[0096] When the share panel 33 is attached to the lower case 31, a smoke exhaust space S1 enclosed by the inner path defining section 70 is formed between the share panel 33 and the lower case 31. As shown in Figure 10, when the lower case 31 and the like are viewed from below in a plan view, the region R1 and the smoke exhaust space S1 overlap.

[0097] The exhaust passage 110 communicates with the smoke exhaust space S1 through openings 75, 76, 77, and 78. The exhaust passage 110 also communicates with the outside through opening 96.

[0098] The detection space S2 (detection space forming member 40) extends in the X direction along a plurality of smoke exhaust holes 31e (holes 28) arranged in the X direction.

[0099] Figure 11 shows a cross-sectional view along the line XI-XI in Figure 10. The cross-section shown in Figure 11 reveals the side collection section 84 of the collection unit 80.

[0100] The bottom plate 31c of the lower case 31 includes a bottom body 31j on which the energy storage cell 10 is arranged, and protruding portions 31k. Multiple protruding portions 31k are formed at intervals in the Y direction. Each protruding portion 31k is formed to extend in the X direction. The protruding portions 31k are formed to protrude downward from the bottom body 31j. The lower end of each protruding portion 31k is located at a hole 28 formed in the cooler 20. A smoke exhaust hole 31e is formed at the lower end of each protruding portion 31k.

[0101] A thermally conductive adhesive 120 is provided between the base body 31j and the cooler 20. The thermally conductive adhesive 120 bonds the base body 31j and the cooler 20. In addition, a thermally conductive adhesive 121 is provided between the base body 31j and the lower surface 6 of the energy storage cell 10. The thermally conductive adhesive 121 bonds the base body 31j and the energy storage cell 10. Each of the thermally conductive adhesives 120 and 121 extends along the X direction.

[0102] The energy storage device 100 is equipped with a heat-resistant plate 130. The heat-resistant plate 130 is positioned on the part of the shear panel 33 that faces the smoke exhaust holes 31e of the lower case 31. Specifically, the heat-resistant plate 130 is positioned on the upper surface 33j (the surface on the smoke exhaust space S1 side) of the main body 33a of the shear panel 33, on the part that faces the smoke exhaust holes 31e. The heat-resistant plate 130 extends in the X direction so as to cover the plurality of smoke exhaust holes 31e (holes 28) arranged in the X direction from below. The heat-resistant plate 130 is made of, for example, mica, which is made by solidifying natural inorganic minerals by heat pressing.

[0103] The energy storage device 100 includes a cross member 36. The cross member 36 is connected to a portion of the bottom plate 31c of the lower case 31 between a pair of adjacent energy storage stacks (between energy storage stack 101 and energy storage stack 102 in Figure 11). The cross member 36 extends along the X direction. The cross member 36 is connected to the peripheral wall 31d (Figure 5). The cross member 36 may be connected to a pair of first frames 921 (Figure 2) via brackets (not shown).

[0104] Figure 12 is a partially enlarged view showing the configuration near the protruding portion 31k. The protruding portion 31k includes a bottom plate 31l and side walls 31m and 31n. Each of the side walls 31m and 31n is formed to connect the bottom plate 31l and the bottom body 31j. A smoke exhaust hole 31e is formed in the bottom plate 31l.

[0105] The energy storage device 100 includes a waterproof sheet 140. The waterproof sheet 140 is positioned on the lower surface of the protruding portion 31k and closes the smoke exhaust holes 31e. The waterproof sheet 140 is formed to extend in the X direction and closes a plurality of smoke exhaust holes 31e arranged in the X direction. The waterproof sheet 140 is an example of a "waterproof seal" as disclosed herein.

[0106] Here, the detection space forming member 40 is formed to be deformable from a standard shape to a bulging shape that bulges downward relative to the standard shape when the pressure in the detection space S2 increases. The pressure in the detection space S2 increases as gas is discharged from the energy storage cell 10. Figure 12 shows the detection space forming member 40 in its standard shape.

[0107] The detection space forming member 40 in the standard shape has a first portion 41, a second portion 42, and a third portion 43. The first portion 41 is located opposite the safety valve SV. The first portion 41 extends horizontally along the energy storage cell 10.

[0108] The second portion 42 is positioned adjacent to the first portion 41. The second portion 42 is formed to recess (protrude) downward from each of the first portion 41 and the third portion 43. The second portion 42 forms a groove 420 extending in the X direction. As a result, when the detection space forming member 40 has a reference shape, the gas discharged from the energy storage cell 10 flows along the groove 420. This makes it possible to quickly circulate the gas to the exhaust gas sensor 50 (Figure 3). The second portion 42 is connected to the Y1 side end and the Y2 side end of the first portion 41.

[0109] The third portion 43 is in contact with the lower surface 6 of the energy storage cell 10. The detection space forming member 40 is provided with a third portion 43 on the Y1 side and a third portion 43 on the Y2 side. The third portion 43 on the Y1 side is connected to the Y1 end of the second portion 42 on the Y1 side. The third portion 43 on the Y2 side is connected to the Y2 end of the second portion 42 on the Y2 side. Each of the third portions 43 on the Y1 side and the Y2 side is connected (for example, by welding) to the portion 6a of the lower surface 6 adjacent to the safety valve SV.

[0110] The energy storage device 100 is equipped with a waterproof adhesive 150. The adhesive 150 is positioned between the bottom plate 31c of the lower case 31 (bottom plate 31l of the protruding portion 31k) and the detection space forming member 40, surrounding the smoke exhaust hole 31e. The adhesive 150 may be a sealing member made of, for example, rubber, which does not have adhesive properties. The adhesive 150 is also an example of a "sealing member" as disclosed herein.

[0111] Specifically, the adhesive 150 includes adhesive 151 and adhesive 152. Adhesive 151 is provided on the Y2 side of the smoke exhaust hole 31e. Adhesive 152 is provided on the Y1 side of the smoke exhaust hole 31e. Each of adhesive 151 and adhesive 152 is positioned on the upper surface of the bottom plate 31l of the protruding portion 31k and is formed to extend in the X direction. Multiple smoke exhaust holes 31e arranged in the X direction are sandwiched in the Y direction by adhesive 151 and adhesive 152.

[0112] Adhesive 151 supports the third portion 43 on the Y2 side from below. Adhesive 152 supports the third portion 43 on the Y1 side from below. That is, each of the two third portions 43 is sandwiched between adhesive 150 (151, 152) and the lower surface 6 of the energy storage cell 10.

[0113] Figure 13 shows the detection space forming member 40 in a deformed state with a bulging shape. The bulging detection space forming member 40 has a first part 41a which is a deformed first part 41 of the standard shape, a second part 42a which is a deformed second part 42 of the standard shape, and a third part 43.

[0114] In the detection space forming member 40 having a bulging shape, the first portion 41a protrudes lower than the second portion 42a. Also, the height H2 in the Z direction of the detection space forming member 40 when it has a standard shape (Figure 12) is smaller than the height H3 of the detection space forming member 40 when it has a bulging shape.

[0115] Furthermore, the volume of the detection space S2 when the detection space forming member 40 has a bulging shape is larger than the volume of the detection space S2 when the detection space forming member 40 has a standard shape (Figure 12). This allows the internal pressure of the detection space S2 to be reduced by the bulging of the detection space forming member 40. As a result, it is possible to suppress the detection space forming member 40 from rupturing excessively early due to an increase in the internal pressure of the detection space S2. This allows sufficient gas to flow through the detection space S2 and enables more reliable gas detection by the exhaust gas sensor 50.

[0116] The detection space forming member 40 has a standard shape when the internal pressure of the detection space S2 is below a predetermined reference value, and deforms into a bulging shape when the internal pressure of the detection space S2 exceeds the above reference value. The detection space forming member 40 may also deform from the bulging shape back into the standard shape when the internal pressure of the detection space S2 decreases from a value greater than the above reference value to a value below the above reference value. The above reference value is a value that has been set in advance based on experimental results during the manufacture of the energy storage device 100, etc.

[0117] Figure 14 shows the state in which the detection space forming member 40 has ruptured due to heat from gas and blast. As a result, the gas in the detection space S2 flows into the exhaust space S1 through the rupture point of the detection space forming member 40 and the exhaust hole 31e (see dashed arrow).

[0118] Figure 15 is a magnified view of the vicinity of the side collection section 84. As shown in Figure 15, the right-hand side 74 of the inner path defining section 70 includes an elastic portion 74a and an adhesive layer 74b. The elastic portion 74a is made of a material that is elastically deformable, such as silicon. The elastic portion 74a is in contact with the lower surface of the cooler 20 (flow section 24A in Figure 15). The adhesive layer 74b adheres the elastic portion 74a to the upper surface of the shear panel 33.

[0119] Therefore, since the elastic portion 74a and the cooler 20 are not bonded together, blast from the energy storage cell 10 may pass between the elastic portion 74a and the cooler 20. The blast that passes between the elastic portion 74a and the cooler 20 is collected by the side collection portion 84.

[0120] Note that the contact position of the right-hand side portion 74 is not limited to the lower surface of the cooler 20. For example, if the cooler 20 is not provided, the inner path defining portion 70 may be in contact with the lower surface of the bottom plate 31c of the lower case 31.

[0121] The side bracket 65 is positioned from the base plate 31c to the peripheral wall 31d. The side bracket 65 is fixed to the base plate 31c and the peripheral wall 31d by bolts or welding, which are not shown.

[0122] The shear panel 33 is fixed to the side bracket 65 by bolts 85. A side collection section 84 is positioned between the shear panel 33 and the side bracket 65. The shear panel 33 contacts the side bracket 65 or the side collection section 84 of the lower case 31, forming the side edge 95 of the outer path defining section 90.

[0123] The side collection unit 84 is located within the side passage 115 of the exhaust passage 110. The side collection unit 84 includes a fixed portion 84a, an inclined portion 84b, and an overhanging portion 84c. The fixed portion 84a is located between the shear panel 33 and the side bracket 65 and is fixed by bolts 85.

[0124] The fixing portion 84a and the side bracket 65 are bonded together by adhesive 84d. The fixing portion 84a is formed to extend from between the shear panel 33 and the side bracket 65 toward the inner path defining portion 70.

[0125] The inclined portion 84b is provided at the tip of the fixed portion 84a, and the protruding portion 84c is formed to extend in the vertical direction toward the center of the right-hand side portion 74.

[0126] As a result, a collection space S3 is formed between the side collection section 84 and the lower case 31. That is, the blast that passes between the elastic section 74a and the cooler 20 is collected in the collection space S3. Meanwhile, a filling section 86 is filled between the side collection section 84 and the shear panel 33. The filling section 86 is made of, for example, resin.

[0127] Although the side bracket 65 and side collection section 84 have been described, the front bracket 61 (front collection section 81), rear brackets 62 and 63 (rear collection section 82), and side bracket 64 (side collection section 83) are formed in the same manner.

[0128] In the energy storage device 100 described above, the detection space forming member 40 is provided to form a detection space S2 between the bottom plate 31c of the lower case 31 and the plurality of energy storage cells 10, and to separate the detection space S2 from the smoke exhaust space S1. As a result, since the detection space S2 is separated from the smoke exhaust space S1, it is possible to suppress the intrusion of moisture from the smoke exhaust space S1 into the detection space S2. As a result, gas in the detection space S2 can be detected using a smoke exhaust sensor 50 that is not waterproofed. This makes it possible to simplify the configuration of the smoke exhaust sensor 50.

[0129] Furthermore, the detection space forming member 40 is formed to be deformable from a standard shape to a bulging shape that expands downward relative to the standard shape when the pressure in the detection space S2 increases. This allows the cross-sectional area of ​​the detection space S2 along the Y direction to be increased when the pressure in the detection space S2 increases, thereby facilitating smooth gas flow in the detection space S2.

[0130] [Differentiation] In the above embodiment, an example was shown in which multiple energy storage cells 10 are arranged in the X direction, but the disclosure is not limited thereto. For example, a single energy storage cell may be formed to extend in the X direction.

[0131] In the above embodiment, an example was shown in which the waterproof sheet 140 and the waterproof adhesive 150 are provided in the vicinity of the smoke exhaust hole 31e and the smoke exhaust hole 31e, but the disclosure is not limited thereto. For example, only one of the waterproof sheet 140 and the waterproof adhesive 150 may be provided.

[0132] In the above embodiment, an example was shown in which the detection space forming member 40 deforms due to an increase in the internal pressure of the detection space S2, but the disclosure is not limited thereto. A detection space forming member that does not deform due to an increase in the internal pressure of the detection space S2 may be provided.

[0133] In the above embodiment, an example is shown in which a heat-resistant plate 130 is provided below the smoke exhaust hole 31e, but the disclosure is not limited thereto. A heat-resistant plate 130 is not required to be provided below the smoke exhaust hole 31e.

[0134] 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]

[0135] 6 Bottom surface, 10 Energy storage cell, 30 Housing, 31 Lower case, 31c Bottom plate (bottom part), 31e Smoke exhaust hole (through hole), 33 Shear panel, 40 Detection space forming member, 41 First part, 42 Second part, 50 Smoke exhaust sensor (detection sensor), 100 Energy storage device, 130 Heat-resistant plate, 140 Waterproof sheet (waterproof seal), 150 Adhesive (sealing member), S1 Smoke exhaust space, SV Safety valve.

Claims

1. A power storage cell including a lower surface on which a safety valve is provided, A housing for housing at least one of the aforementioned energy storage cells, A detection sensor for detecting gas emitted from at least one of the energy storage cells, The system comprises a detection space forming member that forms a detection space in which the gas is detected by the detection sensor, The aforementioned enclosure is A lower case is provided which the lower case is positioned to cover the at least one energy storage cell from below and includes a bottom surface portion in which a through hole is formed at a position overlapping the safety valve, It includes a shear panel positioned below the lower case and forming a smoke exhaust space between itself and the bottom surface of the lower case, The detection space forming member is provided to form the detection space between the bottom surface of the lower case and the at least one energy storage cell, and the detection space is separated from the smoke exhaust space, in an energy storage device.

2. The at least one energy storage cell includes a plurality of energy storage cells arranged in the direction of the arrangement, The energy storage device according to claim 1, wherein the detection space forming member extends in the direction of arrangement along the plurality of energy storage cells.

3. The energy storage device according to claim 1 or 2, further comprising a waterproof seal that closes the through hole formed in the bottom surface of the lower case.

4. The energy storage device according to claim 1 or 2, wherein the detection space forming member is formed to be deformable from a standard shape to a bulging shape that bulges downward relative to the standard shape when the pressure in the detection space increases.

5. The detection space forming member in the aforementioned reference shape includes: A first portion provided in the position of at least one energy storage cell opposite the safety valve, The energy storage device according to claim 4, wherein a second portion is formed which is arranged adjacent to the first portion in an intersecting direction that intersects the vertical direction, and which is formed to be recessed downward from the first portion.

6. The energy storage device according to claim 1 or 2, further comprising a waterproof sealing member disposed between the bottom surface of the lower case and the detection space forming member so as to surround the through hole.

7. The energy storage device according to claim 1 or 2, further comprising a heat-resistant plate disposed in the portion of the share panel facing the through hole formed in the bottom surface of the lower case.

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