Power storage device

Abstract

To provide a power storage device capable of omitting waterproof processing from a power storage cell to a detection sensor which detects gas which is exhausted downward.SOLUTION: A power storage device 100 comprises: a plurality of power storage cells 10 including a bottom face 6 where a safety valve SV is provided; a housing 30 which stores the plurality of power storage cells 10; a smoke exhaust sensor 50 which detects gases exhausted from the plurality of power storage cells; and a detection space formation member 40 which forms a detection space S2 where 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 share panel 33 which forms a smoke exhaust space S1 between the share panel and the bottom plate 31c of the lower case 31. The detection space formation member 40 forms the detection space S2 between the bottom plate 31c of the lower case 31 and the plurality of power storage cells 10, and the detection space S2 is provided so as to be partitioned from the smoke exhaust space S1.SELECTED DRAWING: Figure 11

Description

[Technical Field]

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

[0002] JP 2022-525014 A (Patent Document 1) discloses a power battery pack for use in an electric vehicle. The power battery pack includes a plurality of unit cells. Each of the unit cells is provided with an explosion-proof valve for venting internal smoke or gas. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2022-525014 Summary of the Invention [Problem to be solved by the invention]

[0004] Although not described in Patent Document 1, an explosion-proof valve (safety valve) may be provided on the underside of a cell to allow smoke or gas to be discharged from the underside of the cell (storage cell). In this configuration, a smoke exhaust space (smoke exhaust path) is formed below the cell. A smoke exhaust sensor (detection sensor) that detects gas (smoke) may be placed in the smoke exhaust space. In this case, it is necessary to waterproof the smoke exhaust sensor to reduce the effect of water on the smoke exhaust sensor in the event of flooding, for example.

[0005] The present disclosure has been made to solve the above-mentioned problems, and its purpose is to provide an energy storage device that makes it possible to omit waterproofing treatment for a detection sensor that detects gas discharged downward from a storage cell. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, there is provided an energy storage device including at least one energy storage cell having a lower surface on which a safety valve is provided, a housing that houses the at least one energy storage cell, a detection sensor that detects gas discharged from the 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 that is disposed to cover the at least one energy storage cell from below and that includes a bottom surface portion having a through-hole formed in a position overlapping with the safety valve, and a share panel that is disposed below the lower case and that forms a smoke exhaust space between the lower case and the bottom surface portion of the lower case. The detection space forming member forms a detection space between the bottom surface portion of the lower case and the at least one energy storage cell, and is disposed to separate the detection space from the smoke exhaust space.

[0007] In the energy storage device according to one aspect of the present disclosure, as described above, the detection space-forming member forms a detection space between the bottom surface of the lower case and at least one energy storage cell, and is arranged to separate the detection space from the smoke exhaust space. This prevents water from entering the detection space separated from the smoke exhaust space, even if water enters the smoke exhaust space. As a result, the influence of water on the detection sensor that detects gas in the detection space can be reduced. This eliminates the need for waterproofing the detection sensor.

[0008] The at least one storage cell may include a plurality of storage cells arranged in an arrangement direction. The detection space forming member may extend in the arrangement direction along the plurality of storage cells. With this configuration, gas discharged from each of the plurality of storage cells can easily flow into the detection space.

[0009] The power storage device may include a waterproof seal that closes the through hole formed in the bottom surface of the lower case. This configuration further prevents water from entering the detection space from the smoke exhaust space through the through hole.

[0010] The detection space-forming member may be formed so that it can deform from a reference shape to a bulging shape that bulges downward relative to the reference shape when the pressure in the detection space increases. With this configuration, the vertical height of the detection space-forming member when it has the reference 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 (reference height) of the energy storage device when it is in the reference shape, where no (or only a small) amount of gas is discharged from the energy storage cells, can be made relatively small.

[0011] The detection space-forming member in the reference shape may have a first portion provided in a position facing the safety valve of at least one energy storage cell, and a second portion disposed adjacent to the first portion in a direction intersecting the up-down direction and recessed downward from the first portion. With this configuration, the first portion is disposed relatively closer to the safety valve than the second portion, thereby increasing the effect of gas pressure on the first portion compared to when the distances between the first portion and the safety valve and the second portion are equal. As a result, the first portion can be easily pushed downward by gas pressure, and the detection space-forming member can easily bulge downward.

[0012] The power storage device may include a waterproof seal member disposed between the bottom surface of the lower case and the detection space forming member so as to surround the through hole. This configuration further prevents 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 disposed on the share panel at a portion facing the through-hole formed in the bottom surface of the lower case. This configuration can prevent blast (sparks) released from the safety valve and passing through the through-hole from scattering (adhering) to the share panel. [Effects of the Invention]

[0014] According to the present disclosure, it is possible to omit waterproofing treatment for a detection sensor that detects gas discharged downward from an electricity storage cell. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a diagram schematically illustrating a vehicle including a power storage device according to an embodiment. [Figure 2] 1 is a perspective view showing an electricity storage device and a vehicle body according to an 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 of the power storage device. [Figure 6] FIG. 2 is a perspective view showing the configuration of a lower case to which a bracket unit is attached. [Figure 7] FIG. 2 is an exploded perspective view showing the configuration of a lower case and a cooler. [Figure 8] FIG. 2 is an exploded perspective view showing the configuration of a lower case and an inner path defining portion. [Figure 9] FIG. 2 is an exploded perspective view showing the configuration of a lower case, a collection unit, and a share panel. [Figure 10] FIG. [Figure 11] FIG. 11 is a cross-sectional view taken along line XI-XI in FIG. [Figure 12] FIG. 4 is a partially enlarged view of a detection space forming member having a reference shape. [Figure 13] FIG. 4 is a partially enlarged view of a detection space forming member having a bulging shape. [Figure 14] FIG. 10 is a partially enlarged view of a broken detection space forming member. [Figure 15] FIG. 12 is a partially enlarged view of the vicinity of the side collecting portion in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present disclosure will be described with reference to the accompanying drawings, in which the same or corresponding elements are designated by the same reference numerals.

[0017] An electricity storage device 100 according to an embodiment of the present disclosure will be described with reference to FIGS. 1 to 15. FIG. 1 is a side view schematically illustrating a vehicle 900 including the electricity storage device 100 according to the present 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 X direction and the Y direction are examples of the "arrangement direction" and the "intersecting direction," respectively, in the present disclosure.

[0018] 1 , the vehicle 900 includes, in addition to the power storage device 100, a vehicle body 910 and an equipment unit 930. Examples of the vehicle 900 include a hybrid electric vehicle, a plug-in hybrid electric vehicle, and an electric vehicle (battery electric vehicle). The vehicle body 910 includes a frame member 920. The frame member 920 is disposed on the bottom of the vehicle body 910.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] In this 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.

[0026] 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 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 of the energy storage stacks 101 to 104 (Fig. 2). In this 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 safety valve SV (described later) is indicated by a dashed-dotted arrow.

[0027] 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.

[0028] The cooler 20 cools the plurality of energy storage cells 10. In this embodiment, the cooler 20 cools each of the energy storage stacks 101 to 104. A cooling medium (oil or the like) flows inside the cooler 20.

[0029] The housing 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 the plurality of energy storage cells 10. In this embodiment, the upper cover 32, together with the lower case 31, houses four energy storage stacks 101-104 (FIG. 2) in a sealed state. The upper cover 32 is arranged to cover each of the energy storage stacks 101-104 from above. The lower case 31 is arranged to cover each of the energy storage stacks 101-104 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 provided below the lower case 31. The shear panel 33 has a 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 the share panel 33 of the lower case 31 are located below the plurality of 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 openings 33c, which will be described later. The bottom plate 31c is an example of a "bottom surface portion" in the present disclosure.

[0033] The power storage device 100 includes a smoke sensor 50 that detects gas emitted from each of the plurality of power storage cells 10. The smoke sensor 50 is an example of the "detection sensor" of the present disclosure.

[0034] Here, in conventional power storage devices, the smoke exhaust sensor is located in the smoke exhaust space, so it is necessary to waterproof the smoke exhaust sensor in order to suppress the influence of water on the smoke exhaust sensor, for example, in the event of 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 disposed 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 smoke exhaust space S1. The detection space forming member 40 (detection space S2) is provided below each of the energy storage stacks (101 to 104).

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

[0037] The multiple storage cells 10 are arranged to cover (cap) the upper open end of the detection space forming member 40. This forms a detection space S2 between the multiple storage cells 10 and the detection space forming member 40. Gas discharged downward (toward the detection space S2) from the storage cells 10 flows into the detection space S2 and also flows in the X direction within the detection space S2.

[0038] 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 disposed at each end of the detection space S2 (detection space forming member 40) on the X1 side and the X2 side in the X direction. The smoke exhaust sensor 50 may also be attached to the inner surface of the detection space forming member 40 (the surface on the detection space S2 side).

[0039] The smoke exhaust sensor 50 is provided in each detection space S2. This makes it possible to use the smoke exhaust sensor 50 to individually detect smoke from each of the power storage stacks 101-104.

[0040] The detection space-forming member 40 is made of a material that breaks when exposed to heat. For example, the detection space-forming member 40 is formed of a thin metal film. As a result, the temperature of the detection space-forming member 40 rises while gas is flowing through the detection space S2, causing the detection space-forming member 40 to break. As a result, the gas flowing through the detection space S2 flows into the smoke exhaust space S1 from the break in the detection space-forming member 40. This makes it possible to detect the gas using the smoke exhaust sensor 50 within a certain period of time after the gas is discharged from the energy storage cell 10, and then move the gas from the detection space S2 to the smoke exhaust space S1 as the detection space-forming member 40 breaks.

[0041] 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.

[0042] The equipment unit 930 is disposed, for example, at an end in the X direction. In this embodiment, the equipment unit 930 is disposed on the rear part of the upper cover 32 in the front-rear direction of the vehicle 900. The equipment unit 930 has 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 disposed above the upper cover 32. The junction box 931 houses a relay, a fuse, etc. The junction box 931 is cooled by a first cooler 934 disposed between the junction box 931 and the upper cover 32.

[0044] The power supply unit 932 is disposed above the junction box 931. The power supply unit 932 is cooled by a second cooler 935 disposed on the power supply unit 932. The electronic control unit 933 is disposed 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 disposed on the upper cover 32. The reinforcing member 35 has a function of dispersing a load that is locally applied from above to the electricity storage device 100 by an occupant of the vehicle 900.

[0047] 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 a cell case 12, a pair of external terminals 13, and a safety valve SV. The cell case 12 houses the electrode assembly 11 (Fig. 3).

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[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 end surface on the Z1 side and the end surface on the Z2 side of the energy storage cell 10, respectively.

[0053] A pair of external terminals 13 are provided on the short side surface 1 and the short side surface 2, respectively. The safety valve SV is provided on the bottom surface 6. The safety valve SV opens when the smoke or gas pressure inside the cell casing 12 reaches or 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 casing 12.

[0054] FIG. 5 is a perspective view showing the configuration of the lower case 31. The lower case 31 includes a housing portion 31a and a plate portion 31b. The housing portion 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 front-rear direction (X direction) of the vehicle 900. Furthermore, a plurality of rows of the plurality of smoke exhaust holes 31e arranged in the X direction are arranged in the Y direction (four in FIG. 5). The rows of the plurality of smoke exhaust holes 31e arranged in the X direction are formed below each of the power storage stacks 101-104 (FIG. 2). The smoke exhaust holes 31e are an example of a "through hole" in the present disclosure.

[0055] Furthermore, instead of the plurality of smoke exhaust holes 31e 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 31 is fixed to the upper cover 32, the safety 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 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 disposed in the front (X1 side), a rear wall 31g disposed in the rear (X2 side), a left side wall 31h disposed on the left side (Y1 side), and a right side wall 31i disposed on the right side (Y2 side). The storage section 31a is formed with an opening that opens upward. The plate section 31b is formed to protrude horizontally from the edge of the opening of the storage section 31a.

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

[0058] 6, the energy storage device 100 includes a bracket unit 60 provided on the outer peripheral surface of the housing portion 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 bracket 62 and the rear bracket 63 are each provided on the outer surface of the rear wall 31g. The rear bracket 62 and the rear bracket 63 are arranged with a gap therebetween in the Y direction. A gap 66 is formed between the rear bracket 62 and the rear bracket 63. The gap 66 is located in the center of the rear wall 31g in the Y direction.

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

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

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

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

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

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

[0066] The first cooling section 24 has a circulating section 24A, a circulating section 24B, and a connecting plate 24C. The second cooling section 25 has a circulating section 25A, a circulating section 25B, and a connecting plate 25C. The third cooling section 26 has a circulating section 26A, a circulating section 26B, and a connecting plate 26C. The fourth cooling section 27 has a circulating section 27A, a circulating section 27B, and a connecting plate 27C. 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, so only the first cooling section 24 will be described in detail as a representative.

[0067] The circulating portion 24A and the circulating portion 24B are arranged at an interval in the Y direction. Each of the circulating portion 24A and the circulating portion 24B is formed so as to extend in the X direction.

[0068] The connecting plate 24C is disposed between the circulating portion 24A and the circulating portion 24B, and is provided so as to connect the circulating portion 24A and the circulating portion 24B.

[0069] The connecting plate 24C is formed with a plurality of holes 28. The holes 28 are provided at intervals in the X direction.

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

[0071] Note that, instead of the plurality of holes 28 arranged in the X direction, an opening formed long in the X direction may be formed. In the case of the opening as described above, the smoke exhaust hole 31e formed in the lower case 31 communicates with the opening when the cooler 20 is fixed to the lower case 31. By forming such an opening, it is possible to easily align the opening with the smoke 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 by a thermally conductive adhesive that is not shown in FIG.

[0073] 8, the power storage device 100 includes an inner path defining portion 70. The inner path defining portion 70 is disposed on the lower surface of the cooler 20.

[0074] The inner path defining portion 70 is disposed in the smoke exhaust space S1 (FIG. 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 portion 70 includes a front side portion 71, a rear side portion 72, a left side portion 73, and a right side portion 74. The front side portion 71 and the rear side portion 72 are arranged at an interval from each other in the X direction. Each of the front side portion 71 and the rear side portion 72 extends in the Y direction. The left side portion 73 and the right side portion 74 are arranged at an interval from each other in the Y direction. Each of the left side portion 73 and the right side portion 74 extends in the X direction.

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

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

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

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

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

[0081] 9, the electricity storage device 100 includes a collection unit 80. The collection unit 80 includes a front collection portion 81, a rear collection portion 82, a side collection portion 83, and a side collection portion 84.

[0082] The front collecting portion 81 is fixed to the front bracket 61 and is disposed adjacent to the front side portion 71 .

[0083] The rear collecting portion 82 is fixed to each of the rear brackets 62 and 63 and is disposed adjacent to the rear side portion 72 .

[0084] The side collecting portion 83 is fixed to the side bracket 64 and is disposed adjacent to the left side portion 73. The side collecting portion 84 is fixed to the side bracket 65 and is disposed adjacent to the right side portion 74.

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

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

[0087] The share panel 33 includes a main body 33a and a flange 33b formed on the outer periphery of the main body 33a. The main body 33a is recessed downward relative to the flange 33b. The flange 33b extends 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 a 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 underside of the share panel 33. The peripheral wall 33e rises from the outer periphery 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 in the front, a rear wall 33g located in the rear, a left side wall 33h, and a right side wall 33i. The opening 33c is formed in the rear wall 33g.

[0088] FIG. 10 is a bottom view showing the cooler 20, the bracket unit 60, and the inner path defining portion 70. In FIG. 10, the collection unit 80 is indicated by a dashed line. In FIG. 10, region R1 indicates the region of the bottom plate 31c of the lower case 31 where the smoke exhaust hole 31e (hole 28) is formed. Contact region R2 indicates the region where the collection unit 80 and the bracket unit 60 come into contact. In FIG. 10, hatching is used to clearly show contact region R2. Contact region R2 is located outside the inner path defining portion 70. Contact region R2 is formed to surround the inner path defining portion 70.

[0089] In the contact region R2, the collection unit 80 comes into contact with the bracket unit 60, thereby forming an outer path defining portion 90. That is, the outer path defining portion 90 is located outside the inner path defining portions 70 (71 to 74), and is formed so as to surround the inner path defining portion 70. The outer path defining portion 90 is a seal portion formed by fastening the collection unit 80 and the bracket unit 60 together. This makes it possible to prevent gas and the like from the energy storage cells 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 portion 90 includes a front side portion 91 , a rear side portion 92 , a rear side portion 93 , a side side portion 94 , and a side side portion 95 .

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

[0092] An opening 96 is formed in the outer path defining portion 90. The opening 96 is formed between the rear side portion 92 and the rear side 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 portion 70 and the outer path defining portion 90 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 passage 111 is located between the front edge 71 and the front edge 91. The rear passage 112 is located between the rear edge 72 and the rear edge 92. The rear passage 113 is located between the rear edge 72 and the rear edge 93. The side passage 114 is located between the left edge 73 and the side edge 94. The side passage 115 is located between the right edge 74 and the side edge 95.

[0096] When the shear panel 33 is attached to the lower case 31, a smoke exhaust space S1 surrounded by the inner path regulating portion 70 is formed between the shear panel 33 and the lower case 31. As shown in Fig. 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 each other.

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

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

[0099] Figure 11 shows a cross-sectional view taken along line XI-XI in Figure 10. In the cross section shown in Figure 11, side collection portion 84 of collection unit 80 appears.

[0100] The bottom plate 31c of the lower case 31 includes a bottom main body 31j in which the energy storage cells 10 are arranged, and a protruding portion 31k. A plurality of 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 portion 31k is formed to protrude downward from the bottom main body 31j. The lower end of the protruding portion 31k is located at the hole 28 formed in the cooler 20. The smoke exhaust hole 31e is formed at the lower end of the protruding portion 31k.

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

[0102] The energy storage device 100 includes a heat-resistant plate 130. The heat-resistant plate 130 is disposed in a portion of the share panel 33 facing the smoke exhaust hole 31e of the lower case 31. Specifically, the heat-resistant plate 130 is disposed in a portion of the upper surface 33j (the surface on the smoke exhaust space S1 side) of the main body 33a of the share panel 33 facing the smoke exhaust hole 31e. The heat-resistant plate 130 extends in the X direction so as to cover, from below, the multiple smoke exhaust holes 31e (holes 28) arranged in the X direction. The heat-resistant plate 130 is made of, for example, mica, which is a natural inorganic mineral solidified 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 the energy storage stack 101 and the energy storage stack 102 in FIG. 11). The cross member 36 extends in the X direction. The cross member 36 is connected to the peripheral wall 31d (FIG. 5). The cross member 36 may be connected to a pair of first frames 921 (FIG. 2) via brackets (not shown).

[0104] 12 is a partially enlarged view showing the configuration of the vicinity of 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 power storage device 100 includes a waterproof sheet 140. The waterproof sheet 140 is disposed on the underside of the protruding portion 31k and blocks the smoke exhaust holes 31e. The waterproof sheet 140 is formed to extend in the X direction and blocks the plurality of smoke exhaust holes 31e arranged in the X direction. The waterproof sheet 140 is an example of a "waterproof seal" of the present disclosure.

[0106] Here, the detection space forming member 40 is formed so that it can deform from its reference shape to a bulging shape that bulges downward relative to the reference 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 cells 10. Note that Fig. 12 is a diagram showing the detection space forming member 40 in a state where it has the reference shape.

[0107] In the reference shape, the detection space forming member 40 is formed with a first portion 41, a second portion 42, and a third portion 43. The first portion 41 is provided at a position facing the safety valve SV. The first portion 41 extends horizontally along the energy storage cell 10.

[0108] The second portion 42 is disposed adjacent to the first portion 41. The second portion 42 is formed to be recessed (protrude) downward from each of the first portion 41 and the third portion 43. The second portion 42 forms a groove portion 420 extending in the X direction. This allows gas discharged from the energy storage cell 10 to flow along the groove portion 420 when the detection space forming member 40 has the reference shape. This allows the gas to quickly flow to the smoke sensor 50 (FIG. 3). The second portion 42 is connected to each of 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 Y1-side third portion 43 and a Y2-side third portion 43. The Y1-side third portion 43 is connected to the Y1-side end of the Y1-side second portion 42. The Y2-side third portion 43 is connected to the Y2-side end of the Y2-side second portion 42. The Y1-side and Y2-side third portions 43 are each connected (for example, by welding) to a portion 6a of the lower surface 6 adjacent to the safety valve SV.

[0110] The power storage device 100 includes a waterproof adhesive 150. The adhesive 150 is disposed between the bottom plate 31c of the lower case 31 (the bottom plate 31l of the protruding portion 31k) and the detection space forming member 40 so as to surround the smoke exhaust hole 31e. Note that the adhesive 150 may be a sealing member that does not have adhesive properties and is made of, for example, rubber. The adhesive 150 is an example of the "sealing member" of the present disclosure.

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

[0112] The adhesive 151 supports the third portion 43 on the Y2 side from below. The 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 the adhesive 150 (151, 152) and the lower surface 6 of the energy storage cell 10.

[0113] 13 is a diagram showing the state in which the detection space forming member 40 has been deformed into a bulging shape. The bulging detection space forming member 40 has a first portion 41a that is a deformation of the first portion 41 of the reference shape, a second portion 42a that is a deformation of the second portion 42 of the reference shape, and a third portion 43.

[0114] In the bulging detection space forming member 40, the first portion 41a protrudes downward more than the second portion 42a. Furthermore, the height H2 in the Z direction of the detection space forming member 40 when it has the reference shape (FIG. 12) is smaller than the height H3 of the detection space forming member 40 when it has the 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 its standard shape ( FIG. 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 prevent the detection space-forming member 40 from being ruptured too early due to an increase in the internal pressure of the detection space S2. This allows gas to flow sufficiently through the detection space S2 and enables the smoke sensor 50 to more reliably detect gas.

[0116] The detection space-forming member 40 has a standard shape when the internal pressure of the detection space S2 is equal to or less than a predetermined reference value, and deforms into a bulging shape when the internal pressure of the detection space S2 exceeds the reference value. Note that the detection space-forming member 40 may deform from the bulging shape to the standard shape when the internal pressure of the detection space S2 drops from a value greater than the reference value to equal to or less than the reference value. Note that the reference value is a value that is set in advance based on experimental results during the manufacture of the power storage device 100, etc.

[0117] 14 shows a state in which detection space forming member 40 has been broken due to heat from gas and blast, etc. As a result, gas in detection space S2 flows into smoke exhaust space S1 through the broken part of detection space forming member 40 and smoke exhaust hole 31e (see dashed-dotted arrow).

[0118] 15 is a partially enlarged view of the vicinity of the side collection portion 84. As shown in FIG. 15, the right side portion 74 of the inner path defining portion 70 includes an elastic portion 74a and an adhesive layer 74b. The elastic portion 74a is formed of an elastically deformable material such as silicon. The elastic portion 74a is in contact with the lower surface of the cooler 20 (the flow portion 24A in FIG. 15). The adhesive layer 74b bonds 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 cells 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] The contact position of the right 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 configured to contact the lower surface of the bottom plate 31c of the lower case 31.

[0121] The side bracket 65 is disposed from the bottom plate 31c to the peripheral wall 31d and is fixed to the bottom plate 31c and the peripheral wall 31d by bolts, welding, or the like (not shown).

[0122] The shear panel 33 is fixed to the side bracket 65 by a bolt 85. A side collecting portion 84 is disposed between the shear panel 33 and the side bracket 65. The shear panel 33 comes into contact with the side bracket 65 of the lower case 31 or the side collecting portion 84, thereby forming a side portion 95 of the outer path defining portion 90.

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

[0124] The fixing portion 84a and the side bracket 65 are bonded together with an adhesive 84d. The fixing portion 84a is formed to extend from between the shear panel 33 and the side bracket 65 toward the inside 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 so as to extend toward the center of the right side portion 74 in the vertical direction.

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

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

[0128] In the energy storage device 100 described above, the detection space forming member 40 forms the detection space S2 between the bottom plate 31c of the lower case 31 and the plurality of energy storage cells 10, and is provided to separate the detection space S2 from the smoke exhaust space S1. This separates the detection space S2 from the smoke exhaust space S1, thereby preventing moisture from entering the detection space S2 from the smoke exhaust space S1. As a result, gas in the detection space S2 can be detected using a smoke sensor 50 that is not waterproofed. This allows the configuration of the smoke sensor 50 to be simplified.

[0129] Furthermore, detection space forming member 40 is formed so that it can deform from its base shape to a bulging shape that bulges downward relative to the base shape when the pressure in detection space S2 increases. This allows the cross-sectional area of ​​detection space S2 in the Y direction to increase when the pressure in detection space S2 increases, thereby allowing gas to flow smoothly through detection space S2.

[0130] [Variations] In the above embodiment, an example has been shown in which a plurality of energy storage cells 10 are arranged in the X direction, but the present disclosure is not limited to this. For example, one energy storage cell may be formed to extend in the X direction.

[0131] In the above embodiment, the waterproof sheet 140 and the waterproof adhesive 150 are provided near the smoke exhaust hole 31 e and the smoke exhaust hole 31 e, respectively, but the present disclosure is not limited to this. 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 is deformed by an increase in the internal pressure of the detection space S2, but the present disclosure is not limited to this. A detection space forming member that does not deform by an increase in the internal pressure of the detection space S2 may be provided.

[0133] In the above embodiment, an example in which the heat-resistant plate 130 is provided below the smoke exhaust hole 31e has been described, but the present disclosure is not limited to this. The heat-resistant plate 130 does not have 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 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]

[0135] 6 bottom surface, 10 storage cell, 30 housing, 31 lower case, 31c bottom plate (bottom portion), 31e smoke exhaust hole (through hole), 33 share panel, 40 detection space forming member, 41 first part, 42 second part, 50 smoke exhaust sensor (detection sensor), 100 storage device, 130 heat-resistant plate, 140 waterproof sheet (waterproof seal), 150 adhesive (sealing material), S1 smoke exhaust space, SV safety valve.

Claims

1. At least one storage cell including a lower surface provided with a safety valve; a housing that houses the at least one storage cell; a detection sensor that detects gas discharged from the at least one power storage cell; 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 disposed to cover the at least one energy storage cell from below, the lower case including a bottom surface portion having a through-hole formed at a position overlapping with the safety valve; a share panel disposed below the lower case and forming a smoke exhaust space between the share panel and the bottom surface of the lower case, the detection space forming member forms the detection space between the bottom surface portion of the lower case and the at least one storage cell, and is arranged so as to separate the detection space from the smoke exhaust space.

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

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

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

5. The detection space forming member in the reference shape has: a first portion provided at a position facing the safety valve of the at least one energy storage cell; 5. The power storage device according to claim 4, further comprising: a second portion disposed adjacent to the first portion in a direction intersecting the vertical direction and recessed downward from the first portion.

6. The power storage device according to claim 1 , further comprising: a waterproof seal 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 power storage device according to claim 1 , further comprising a heat-resistant plate disposed in a portion of the shared panel facing the through-hole formed in the bottom surface portion of the lower case.

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