Energy storage device

Abstract

The energy storage device can suppress misalignment of the electrode body by using the exhaust valves on the energy storage cells mounted in the device, thereby preventing damage to the electrode body of the energy storage cell. [Solution] The energy storage device 3 comprises an electrode body 80 and a housing case 20 that houses the electrode body 80. The housing case 20 includes a first main wall 31 in which a valve hole 34 is formed, and a smoke exhaust valve 50 that closes the valve hole 34. The smoke exhaust valve 50 has a cylindrical member 51, a closing membrane member 52 formed inside the cylindrical member 51, and an engaging member 53 and a support member 55 connected to the cylindrical member 51. The cylindrical member 51 is formed along the hole surface 34a that defines the valve hole 34. The engaging member 53 is formed on the outer surface 31a of the first main wall. The support member 55 is formed on the inner surface 31b of the first main wall and is formed to support the electrode body 80.

Description

Technical Field

[0001] The present disclosure relates to a power storage device.

Background Art

[0002] Various power storage cells of power storage devices have been proposed. For example, Japanese Patent Application Laid-Open No. 2023-173774 discloses a power storage cell having a housing case and an electrode body housed in the housing case. An exhaust valve member is formed in a wall portion of the housing case.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, in a power storage cell which is a secondary battery, with charging and discharging, the electrode body housed in the power storage cell repeats expansion and contraction. As a result, there is a risk of damage to a current collecting tab or the like constituting the electrode body due to, for example, displacement of the electrode body.

[0005] The present disclosure has been made in view of the above problems, and an object thereof is to provide a power storage device capable of suppressing displacement of an electrode body by an exhaust valve of a power storage cell mounted on the power storage device and suppressing damage to the electrode body of the power storage cell.

Means for Solving the Problems

[0006] The energy storage device according to this disclosure comprises an electrode body and a housing case for housing the electrode body. The housing case includes a first main wall in which a valve hole is formed and a smoke exhaust valve for closing the valve hole. The smoke exhaust valve has a cylindrical member, a closing membrane member formed inside the cylindrical member, and an engaging member and a support member connected to the cylindrical member. The cylindrical member is formed along the hole surface that defines the valve hole. The engaging member is formed on the outer surface of the first main wall. The support member is formed on the inner surface of the first main wall and is also formed to support the electrode body.

[0007] A water-repellent film with higher water repellency than the closing membrane member of the energy storage device according to this disclosure may be formed on the outer surface of the closing membrane member.

[0008] The inner surface of the sealing membrane member of the energy storage device according to this disclosure may have an uneven shape formed thereon. The housing case for the energy storage device according to this disclosure has a second main wall arranged at a distance from the first main wall in a first direction, and a peripheral wall formed to connect the first main wall and the second main wall. The peripheral wall has a first side wall and a second side wall arranged at a distance from each other in a second direction intersecting the first direction. The support member is formed to extend from the first side wall to the second side wall.

[0009] The support member of the energy storage device relating to this disclosure may be in contact with the electrode body. [Effects of the Invention]

[0010] According to the energy storage device described herein, the exhaust valves of the energy storage cells mounted in the energy storage device can suppress displacement of the electrode bodies, thereby preventing damage to the electrode bodies of the energy storage cells. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram showing a vehicle equipped with an energy storage device according to an embodiment of the present disclosure. [Figure 2] This is an exploded perspective view of the energy storage device in an embodiment of the present disclosure. [Figure 3]This is a perspective view of a storage cell in an energy storage device according to an embodiment of the present disclosure. [Figure 4] This is an exploded perspective view of a storage cell in an embodiment of the present disclosure. [Figure 5] Figure 3 is a cross-sectional view of the energy storage device shown, viewed in the direction of the VV arrow. [Figure 6] This is a cross-sectional view of a modified example 1 of the occlusion membrane member shown in Figure 5 in the embodiment of this disclosure. [Figure 7] This is a perspective view of a modified example 2 of the energy storage cell in the embodiment of the present disclosure. [Figure 8] Figure 7 is a cross-sectional view of modified example 2 of the energy storage cell, viewed in the direction of the VIII-VIII arrow. [Modes for carrying out the invention]

[0012] Embodiments and modifications of this disclosure will be described in detail below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and their descriptions will not be repeated. <Embodiment> Figure 1 is a schematic side view of a vehicle equipped with an energy storage device according to an embodiment of the present disclosure. In Figure 1, the vertical direction H indicates the vertical direction of the vehicle 1. The width direction W indicates the width direction of the vehicle 1. The longitudinal direction D indicates the longitudinal direction of the vehicle 1. The vertical direction H is an example of the "first direction" according to the present disclosure, and the width direction W is an example of the "second direction" according to the present disclosure.

[0013] Vehicle 1 comprises a vehicle body 2 and an energy storage device 3. Vehicle 1 includes, for example, a PHEV (Plug-in Hybrid Electric Vehicle), a BEV (Battery Electric Vehicle), or an FCEV (Fuel Cell Electric Vehicle). The energy storage device 3 is mounted on the underside of the vehicle body 2.

[0014] Figure 2 is an exploded perspective view of an energy storage device in an embodiment of the present disclosure. The energy storage device 3 comprises a storage case 4 and an energy storage stack 15.

[0015] The storage case 4 includes an upper cover 5 and a lower case 6. The storage case 4 forms a storage space V defined by the upper cover 5 and the lower case 6.

[0016] The upper cover 5 is formed to cover the lower case 6 which is formed to open upward.

[0017] The lower case 6 includes a bottom wall 7 and a wall portion 8. The bottom wall 7 supports the power storage stack 15 in the vertical direction H.

[0018] The wall portion 8 is formed to rise upward from the bottom wall 7 in the vertical direction H. The wall portion 8 has a peripheral wall 9 and a reinforcing portion 12. The peripheral wall 9 is formed to extend in a frame shape and is formed to extend upward in the vertical direction H from the outer peripheral edge portion of the bottom wall 7. The peripheral wall 9 has a first standing wall 10 and a second standing wall 11. The first standing wall 10 and the second standing wall 11 are formed to extend in the front-rear direction D and are arranged at intervals in the width direction W.

[0019] The reinforcing portion 12 is formed to extend in the front-rear direction D. The reinforcing portion 12 is arranged so as to pass through the center between the first standing wall 10 and the second standing wall 11 in the width direction W.

[0020] The power storage stack 15 is housed in the storage space V and is arranged on the upper surface of the bottom wall 7. The power storage stack 15 is formed from a plurality of power storage cells 100. The plurality of power storage cells 100 are arranged in the front-rear direction D. The power storage cell 100 is formed in a rectangular parallelepiped shape that is long in the width direction W.

[0021] Fig. 3 shows a perspective view of the power storage cell 100. As shown in Fig. 3, the power storage cell 100 according to the present embodiment is a so-called square battery. The power storage cell 100 may be a secondary battery configured to be capable of charging and discharging, such as a lithium ion battery or a nickel hydrogen battery.

[0022] Figure 4 is an exploded perspective view of the energy storage cell according to this embodiment. As shown in Figure 4, the energy storage cell 100 comprises a housing case 20, an insulating member 70, and a plurality of electrode bodies 80.

[0023] The housing case 20 is conductive. The housing case 20 is made of a metal such as aluminum. The housing case 20 houses a plurality of electrode bodies 80. The housing case 20 also houses an electrolyte not shown in Figure 4. The housing case 20 includes a case body 21 and a top plate 30.

[0024] The case body 21 includes a bottom plate 22 and a peripheral wall 23 that rises from the bottom plate 22. The bottom plate 22 is joined to the peripheral wall 23 at its outer peripheral edge. The bottom plate 22 is an example of the "second main wall" of this disclosure.

[0025] The peripheral wall 23 rises from the base plate 22. The peripheral wall 23 is formed to connect the base plate 22 and the top plate body 31, which will be described later. The peripheral wall 23 has a roughly rectangular outer shape when viewed from the vertical direction H. The peripheral wall 23 is made of a metal such as aluminum. The peripheral wall 23 has a first side wall 23a and a second side wall 23b as shown in Figure 5. The first side wall 23a and the second side wall 23b are spaced apart in the width direction W.

[0026] Referring again to Figure 4, the top plate 30 includes a top plate body 31, an insulating cover 35, electrode terminals 40, and a smoke exhaust valve 50. The top plate body 31 is an example of the "first main wall" of this disclosure.

[0027] The top plate body 31 is joined to the outer peripheral edge of the peripheral wall 23 by welding or the like so as to close the opening in the peripheral wall 23. The top plate body 31 is arranged with a gap between it and the bottom plate 22 in the vertical direction H. The top plate body 31 has an outer surface 31a and an inner surface 31b. The inner surface 31b and the outer surface 31a are arranged with a gap between them in the vertical direction H. The outer surface 31a is positioned further away from the electrode body 80 compared to the inner surface 31b. The top plate body 31 has a first connecting hole 32, a second connecting hole 33, and a valve hole 34 formed therein. The valve hole 34 is formed in the top plate body 31 between the first connecting hole 32 and the second connecting hole 33 in the width direction W. The valve hole 34 is defined by the hole surface 34a of the top plate body 31.

[0028] The insulating cover 35 covers the outer surface 31a of the top panel body 31. The electrode terminal 40 is provided on the top plate body 31. The electrode terminal 40 includes a first external terminal 41A, a second external terminal 41B, a first connecting member 42A, a second connecting member 42B, a first seal ring 43A, a second seal ring 43B, a first terminal support portion 44A, and a second terminal support portion 44B.

[0029] The first external terminal 41A and the second external terminal 41B are provided in the energy storage cell 100 so as to be exposed to the outside.

[0030] The first connecting member 42A and the second connecting member 42B are electrically conductive. At least a portion of the first connecting member 42A and the second connecting member 42B are located inside the housing case 20.

[0031] The first external terminal 41A or the first connecting member 42A is inserted through the first connecting hole 32. The first external terminal 41A and the first connecting member 42A are joined to each other. The first connecting member 42A is electrically connected to the electrode body 80. As a result, the first external terminal 41A is electrically connected to the electrode body 80.

[0032] The second external terminal 41B or the second connecting member 42B is inserted through the second connecting hole 33. The second external terminal 41B and the second connecting member 42B are joined to each other. The second connecting member 42B is electrically connected to the electrode body 80. As a result, the second external terminal 41B is electrically connected to the electrode body 80.

[0033] The first seal ring 43A is provided along the first connecting hole 32. The first seal ring 43A is provided in the gap between the top plate body 31 and the first external terminal 41A, and seals this gap. The second seal ring 43B is provided along the second connecting hole 33. The second seal ring 43B is provided in the gap between the top plate body 31 and the second external terminal 41B, and seals this gap. The first seal ring 43A and the second seal ring 43B have electrical insulating properties.

[0034] The first terminal support portion 44A is locked to the top plate body 31. The first terminal support portion 44A supports the first external terminal 41A from the outer circumference of the first external terminal 41A. The first terminal support portion 44A includes a first locking ring 45A and a first covering ring 46A. The first locking ring 45A extends in an annular shape so as to surround the first connecting hole 32 and is locked directly to the top plate body 31. The first covering ring 46A covers the first locking ring 45A. The first locking ring 45A supports the first external terminal 41A via the first covering ring 46A. The first covering ring 46A is made of an electrically insulating resin material.

[0035] The second terminal support portion 44B is locked to the top plate body 31. The second terminal support portion 44B supports the second external terminal 41B from the outer circumference of the second external terminal 41B. The second terminal support portion 44B includes a second locking ring 45B and a second covering ring 46B. The second locking ring 45B extends in an annular shape so as to surround the second connecting hole 33 and is directly locked to the top plate body 31. The second covering ring 46B covers the second locking ring 45B. The second locking ring 45B supports the second external terminal 41B via the second covering ring 46B. The second covering ring 46B is made of an electrically insulating resin material.

[0036] The smoke exhaust valve 50 includes a cylindrical member 51, a closing membrane member 52, an engaging member 53, and a support member 55. The smoke exhaust valve 50 is formed to close the valve hole 34. Details of the smoke exhaust valve 50 will be explained later in Figure 5. In Figure 4, the cylindrical member 51, closing membrane member 52, engaging member 53, and support member 55 of the smoke exhaust valve 50 are shown separately, but the smoke exhaust valve 50 and the top plate 30 may be formed as a single unit. Alternatively, the cylindrical member 51, closing membrane member 52, engaging member 53, and support member 55 of the smoke exhaust valve 50 may be formed as a single unit with the exception of some members.

[0037] The insulating member 70 has electrical insulating properties. The insulating member 70 is positioned between the electrode body 80 and the housing case 20. The insulating member 70 electrically insulates the electrode body 80 from the housing case 20. The insulating member 70 includes an insulating bracket 71, a circumferential insulating portion 72, and a bottom insulating portion 73.

[0038] The insulating bracket 71 is positioned between the electrode body 80 and the top plate body 31. The insulating bracket 71 is relatively rigid and is in contact with both the electrode body 80 and the top plate body 31. As a result, the electrode body 80 is fixed to the housing case 20 in the vertical direction H. The circumferential insulating portion 72 is positioned between the electrode body 80 and the circumferential wall 23. The circumferential insulating portion 72 is made of a film-like material. The bottom insulating portion 73 is positioned between the electrode body 80 and the bottom plate 22. The bottom insulating portion 73 is made of a film-like material. In this embodiment, the bottom insulating portion 73 is bonded to the electrode body 80.

[0039] The electrode body 80 is a so-called wound electrode body. The electrode body 80 typically has a first electrode body 81 and a second electrode body 82. The first electrode body 81 and the second electrode body 82 are arranged adjacent to each other in the front-to-back direction D. The circumferential insulating portion 72 may integrally cover the electrode body 80 so that the first electrode body 81 and the second electrode body 82 are fixed to each other. The first electrode body 81 is formed by winding a group of sheets around a winding axis α1. The first axial direction A1 of the winding axis α1 is in the direction that passes through the case body 21 and the top plate body 31, and is in the same direction as the up-and-down direction H. The electrode sheet group has, for example, a first separator, a first electrode sheet, a second separator, and a second electrode sheet. The sheet group is wound around the winding axis α1, so that the first separator, the first electrode sheet, the second separator, and the second electrode sheet are stacked in a first radial direction R1 that intersects with the first axial direction A1 and is centered on the first axial direction A1. The first electrode sheet has a first current collector sheet and a first active material layer. The first active material layer is coated on both sides of the first current collector sheet. The second electrode sheet has a second current collector sheet and a second active material layer. The second active material layer is coated on both sides of the second current collector sheet. For example, the first electrode sheet is the positive electrode and the second electrode sheet is the negative electrode. The first electrode body 81 and the second electrode body 82 have substantially the same configuration.

[0040] The first electrode body 81 has a first tab 91A and a second tab 91B. The second electrode body 82 has a first tab 92A and a second tab 92B. The first tab 91A electrically connects a first electrode (not shown) of the first electrode body 81 to the first connecting member 42A. The second tab 91B electrically connects a second electrode (not shown) of the first electrode body 81 to the second connecting member 42B. The first tab 92A electrically connects a second electrode (not shown) of the second electrode body 82 to the first connecting member 42A. The second tab 92B electrically connects a second electrode (not shown) of the second electrode body 82 to the second connecting member 42B.

[0041] The first tab 91A and the first tab 92A are arranged side by side in the front-to-back direction D. The first tab 91A and the first tab 92A are joined to each other, for example by ultrasonic welding. The first tab 91A and the first tab 92A are joined to the first connecting member 42A, for example by ultrasonic welding. The second tab 91B and the second tab 92B are arranged side by side in the front-to-back direction D. The second tab 91B and the second tab 92B are joined to each other, for example by ultrasonic welding. The second tab 91B and the second tab 92B are joined to the second connecting member 42B, for example by ultrasonic welding.

[0042] Figure 5 is a cross-sectional view of the energy storage cell shown in Figure 3, viewed in the direction of the VV arrow. The smoke exhaust valve 50 includes a cylindrical member 51, a sealing membrane member 52, an engaging member 53, and a support member 55. The smoke exhaust valve 50 is formed from, for example, an electrically insulating resin material. In Figure 5, the cylindrical member 51, the sealing membrane member 52, and the support member 55 may be formed integrally.

[0043] The cylindrical member 51 is formed along the hole surface 34a that defines the valve hole 34. The cylindrical member 51 is formed to extend in an annular shape in the vertical direction H. The cylindrical member 51 has an outer peripheral surface 51a, an inner peripheral surface 51b, a first end surface 51c, and a second end surface 51d. The cylindrical member 51 is connected to the hole surface 34a at the outer peripheral surface 51a. The first end surface 51c and the second end surface 51d are spaced apart in the vertical direction H. The first end surface 51c is positioned further away from the electrode body 80 compared to the outer surface 31a of the top plate body 31. That is, the first end surface 51c is positioned on the opposite side of the electrode body 80 with respect to the top plate body 31 in the vertical direction H, and is positioned further away from the outer surface 31a of the top plate body 31 in the vertical direction. The second end surface 51d is positioned closer to the electrode body 80 compared to the inner surface 31b. In other words, the second end face 51d is positioned on the electrode body 80 side with respect to the top plate body 31 in the vertical direction H.

[0044] The occlusion membrane member 52 is formed inside the cylindrical member 51. The occlusion membrane member 52 closes the cylindrical member 51. More specifically, the occlusion membrane member 52 closes the cylindrical member 51 by connecting to the inner circumferential surface 51b of the cylindrical member 51. The occlusion membrane member 52 has an outer surface 52a and an inner surface 52b. The outer surface 52a and the inner surface 52b are spaced apart in the vertical direction H. The outer surface 52a is located further away from the electrode body 80 compared to the inner surface 52b. The inner surface 52b is located closer to the electrode body 80 compared to the outer surface 52a. A water-repellent film 52c may be formed on the outer surface 52a of the occlusion membrane member 52.

[0045] Here, the water-repellent film 52c has higher water repellency than the sealing film member 52. Here, the statement that the water-repellent film 52c has higher water repellency than the sealing film member 52 means, for example, that the wetting tension of the material forming the water-repellent film 52c is smaller than that of the material forming the sealing film member 52. The wetting tension [mN / m] is measured based on the test method described in JIS K 6768. That is, the wetting tension [mN / m] is measured by dropping several liquids with progressively different surface tensions onto the surface of the target material and observing how the liquids spread. Alternatively, the statement that the water-repellent film 52c has higher water repellency than the sealing film member 52 means, for example, that when liquids are dropped onto the material forming the water-repellent film 52c and the material forming the sealing film member 52, the contact angle, which is the angle of the tangency at the edge of the droplet on the material forming the water-repellent film 52c, is larger than the tangency angle of the droplet on the material forming the sealing film member 52.

[0046] The engaging member 53 is connected to the cylindrical member 51. The engaging member 53 is formed to extend in the width direction W along the outer surface 31a of the top plate body 31. A connecting hole 54 is formed in the engaging member 53. The connecting hole 54 is defined by the hole surface 54a. The engaging member 53 is connected to the outer surface 51a at the hole surface 54a.

[0047] The support member 55 is formed to extend in the width direction W. The support member 55 is connected to the cylindrical member 51. The support member 55 is formed to extend along the inner surface 31b. As a result, the support member 55 is formed to protrude from the top plate body 31 toward the electrode body 80. More specifically, the support member 55 has a first main surface 55a and a second main surface 55b. The first main surface 55a and the second main surface 55b are spaced apart in the vertical direction H. The first main surface 55a faces the top plate body 31 in the vertical direction H. The second main surface 55b faces the electrode body 80 in the vertical direction H. The second main surface 55b may be in contact with the electrode body 80 or may be spaced apart in the vertical direction H.

[0048] The support member 55 is formed to extend from the first side wall 23a to the second side wall 23b. Here, the statement that the support member 55 is formed to extend from the first side wall 23a to the second side wall 23b includes the case where the support member 55 is in contact with the first side wall 23a and the second side wall 23b, and the case where the support member 55 is in close proximity to the first side wall 23a and the second side wall 23b, for example with an insulating bracket 71 in between.

[0049] The support member 55 has a bypass hole 56 formed therein. The bypass hole 56 is a hole that penetrates the support member 55 in the vertical direction H. When the support member 55, electrode body 80 and electrode terminal 40 are viewed from above in the vertical direction H, the bypass hole 56 of the support member 55 is formed so as not to overlap with the first connecting member 42A, the second connecting member 42B, the first tab 91A, the first tab 92A, the second tab 91B, and the second tab 92B.

[0050] The support member 55 is formed to support the electrode body 80. Here, "the support member 55 is formed to support the electrode body 80" includes not only the case where the support member 55 is in contact with the electrode body 80, but also the case where the second main surface 55b of the support member 55 is positioned at a distance from the electrode body 80. More specifically, an example of the support member 55 being formed to support the electrode body 80 is described, which includes a case where, when stationary, the support member 55 is positioned at a distance from the multiple electrode bodies 80, but when the vehicle 1 is driven, the electrode bodies vibrate and the electrode bodies 80 come into contact with the support member 55. Alternatively, it includes a case where, when the energy storage cell 100 is in use, the electrode bodies 80 expand and the support member 55 comes into contact with the electrode bodies 80.

[0051] In the embodiment of the present disclosure, the cylindrical member 51 of the energy storage device 3 connects the engaging member 53 and the support member 55. As a result, the engaging member 53 and the support member 55 sandwich the top plate body 31. With this configuration, it is possible to prevent the smoke exhaust valve 50 from falling off the top plate body 31 due to out-of-plane loads acting on the top plate 30 caused by factors such as the pressure difference between the inside and outside of the housing case 20.

[0052] In the embodiment of the present disclosure, the support member 55 of the energy storage device 3 is formed to support the electrode body 80. This allows the support member 55 to prevent damage to the first tab 91A of the electrode body 80 or the current collector sheet forming the electrode body 80, for example, when the electrode body 80 housed in the housing case 20 vibrates during the operation of the vehicle 1. Alternatively, the support member 55 can prevent damage to the first tab 91A, such as when the electrode body 80 expands due to charging and discharging of the energy storage cell 100 and the first tab 91A is pressed against the top plate body 31.

[0053] In the embodiment of this disclosure, the exhaust valve 50 and electrode terminals 40 of the energy storage device 3 are provided on the top plate body 31. This makes it possible to suppress an increase in the dimensions of the energy storage cell 100. <Example 1> In embodiments of this disclosure, the gas permeability of the material forming the smoke exhaust valve 50 to carbon dioxide is 1 [g·m³]. 2 The humidity may be 24 hours and 1 atm or higher. Specifically, the material forming the smoke exhaust valve 50 is a resin material such as polyethylene or polypropylene. Also, as shown in Figure 6, an uneven shape may be formed on the inner surface 52b of the occlusion membrane member 52. With this configuration, the surface area of ​​the inner surface 52b can be increased. This allows carbon dioxide generated inside the containment case 20 to be permeated and discharged, thereby suppressing the expansion of the containment case 20. <Modification 2> The first electrode body 81 is a wound electrode body formed by winding an electrode sheet around a winding axis α1. In the embodiments of this disclosure, the first axial direction A1 of the winding axis α1 is shown as passing through the bottom plate 22 and the top plate body 31, and is in the same direction as the vertical direction H, but this disclosure is not limited to this. For example, the axial direction of the winding axis of the first electrode body 81 may be passing through the first side wall 23a and the second side wall 23b, and is in the same direction as the width direction W.

[0054] Figure 7 shows a perspective view of a modified example of the energy storage cell according to the embodiment of the present disclosure. Energy storage cell 101, which is a modified example of energy storage cell 100, has substantially the same configuration as energy storage cell 100, except as described below.

[0055] The energy storage cell 101 has a housing case 20 that houses the first electrode body 81. The housing case 20 has a case body 21 and a top plate body 31. The case body 21 has a bottom plate 22 and a peripheral wall 23 formed to rise from the bottom plate 22. The top plate body 31 and the bottom plate 22 are spaced apart in the vertical direction H. That is, the peripheral wall 23 is formed to connect the top plate body 31 and the bottom plate 22. A smoke exhaust valve 50 is provided on the top plate body 31. The peripheral wall 23 has a first side wall 23a and a second side wall 23b. The first side wall 23a and the second side wall 23b are spaced apart in the width direction W. Electrode terminals 40 are provided on each of the first side wall 23a and the second side wall 23b.

[0056] Here, in the energy storage cell 101, the second axial direction A2 of the winding axis α2 of the first electrode body 81 is in the direction that passes through the first side wall 23a and the second side wall 23b, and is in the same direction as the width direction W. The smoke exhaust valve 50 and the first electrode body 81 are arranged side by side in the second radial direction R2, which intersects the second axial direction A2 with respect to the winding axis α2.

[0057] Figure 8 shows a cross-sectional view of the energy storage cell shown in Figure 7, viewed in the direction of the VIII-VIII arrow. The first electrode body 81 has a first arc portion 81a, a second arc portion 81b, and a flat portion 81c. The flat portion 81c connects the first arc portion 81a and the second arc portion 81b. The first arc portion 81a and the second arc portion 81b are spaced apart in the vertical direction H. The first arc portion 81a is positioned closer to the smoke exhaust valve 50 in the vertical direction H compared to the second arc portion 81b. The smoke exhaust valve 50 has a support member 55 formed along the first arc portion 81a. That is, the second main surface 55b of the support member 55 is formed to support the first electrode body 81. The support member 55 may be in contact with the first arc portion 81a of the first electrode body 81, or it may be formed to be spaced apart from the first arc portion 81a.

[0058] In this way, the support member 55 formed along the first arc portion 81a can have a larger contact area with the first electrode body 81 compared to a support member formed without following the first arc portion 81a. This makes it possible to suppress the application of localized loads to the first electrode body 81 due to the support of the support member 55. As a result, damage to the first electrode body 81 can be suppressed.

[0059] While embodiments of this disclosure have been described above, the embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The technical scope provided herein is defined by the claims and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0060] 1 Vehicle, 2 Body, 3 Energy storage device, 4 Storage case, 5 Upper cover, 6 Lower case, 7 Bottom wall, 8 Wall section, 9 Peripheral wall, 10 First upright wall, 11 Second upright wall, 12 Reinforcement section, 15 Energy storage stack, 20 Housing case, 21 Case body, 22 Bottom plate, 23 Peripheral wall, 23a First side wall, 23b Second side wall, 30 Top plate, 31 Top plate body, 31a Outer surface, 31b Inner surface, 32 First connecting hole, 33 Second connecting hole, 34 Valve hole, 34a Hole surface, 35 Insulating cover, 40 Electrode terminal, 41A First external terminal, 41B Second external terminal, 42A First connecting member, 42B Second connecting member, 43A First seal ring, 43B Second seal ring, 44A First terminal support section, 44B 45A Second terminal support, 45B First locking ring, 46A First covering ring, 46B Second covering ring, 50 Smoke exhaust valve, 51 Cylindrical member, 51a Outer surface, 51b Inner surface, 51c First end face, 51d Second end face, 52 Closure membrane member, 52a Outer surface, 52b Inner surface, 52c Water-repellent film, 53 Engagement member, 54 Connection hole, 54a Hole surface, 55 Support member, 55a First main surface, 55b Second main surface, 56 Avoidance hole, 70 Insulating member, 71 Insulating bracket, 72 Circumferential insulating part, 73 Bottom insulating part, 80 Electrode body, 81 First electrode body, 81a First arc part, 81b Second arc part, 81c Flat part, 82 Second electrode body, 91A First tab, 91B Second tab, 92A First tab, 92B Second tab, 100 Energy storage cell, 101 Energy storage cell, V Enclosure space, α1 Winding axis, α2 Winding axis.

Claims

1. It comprises an electrode body and a housing case for housing the electrode body, The aforementioned housing case includes a first main wall in which a valve hole is formed, and a smoke exhaust valve that closes the valve hole. The smoke exhaust valve comprises a cylindrical member, a sealing membrane member formed inside the cylindrical member, and an engaging member and a support member connected to the cylindrical member. The cylindrical member is formed along the hole surface that defines the valve hole, The engaging member is formed on the outer surface of the first main wall, The support member is formed on the inner surface of the first main wall and is also formed to support the electrode body in the energy storage device.

2. The energy storage device according to claim 1, wherein a water-repellent film with higher water repellency than the closing membrane member is formed on the outer surface of the closing membrane member.

3. The energy storage device according to claim 1, wherein an uneven shape is formed on the inner surface of the sealing membrane member.

4. The housing case has a second main wall arranged at a distance from the first main wall in a first direction, and a peripheral wall formed to connect the first main wall and the second main wall. The peripheral wall has a first side wall and a second side wall that are spaced apart in a second direction intersecting the first direction. The energy storage device according to claim 1, wherein the support member is formed to extend from the first side wall to the second side wall.

5. The energy storage device according to claim 1, wherein the support member is in contact with the electrode body.

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