Power storage device

Abstract

To provide a power storage device that enables a power storage cell to be easily removed from a case.SOLUTION: A power storage device 100 comprises a plurality of power storage cells 11, and a case 20 that houses the plurality of power storage cells 11. The case 20 includes a cooling plate 23 (stationary portion) that is fixed to the plurality of power storage cells 11, and a bottom surface 22a (stationary portion). In the power storage device 100, a hollow member 60 (fragile member) is arranged between the plurality of power storage cells 11 and each of the cooling plate 23 and the bottom surface 22a.SELECTED DRAWING: Figure 4

Description

Technical Field

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

Background Art

[0002] Japanese Patent Application Laid-Open No. 2021-111520 (Patent Document 1) discloses a battery pack including a plurality of battery cells and a battery pack case. Each of the plurality of battery cells is adhered to the floor surface of the battery pack case.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, when recycling the battery cell, etc., it is necessary to remove the battery cell from the battery pack case. However, in the battery pack described in Patent Document 1 above, since the battery cell is adhered to the floor surface of the battery pack case, it is difficult to remove the battery cell (power storage cell).

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to provide a power storage device capable of easily removing a power storage cell from a case.

Means for Solving the Problems

[0006] A power storage device according to one aspect of the present disclosure includes at least one power storage cell and a case that houses the at least one power storage cell. The case includes at least one fixing portion fixed to the at least one power storage cell. A fragile portion is formed between the at least one power storage cell and the at least one fixing portion.

[0007] In the power storage device according to one aspect of the present disclosure, as described above, a fragile portion is formed between the at least one power storage cell and the at least one fixing portion. Thereby, the at least one fixing portion can be easily peeled off from the at least one power storage cell starting from the fragile portion. Therefore, the power storage cell can be easily removed from the case.

[0008] In the power storage device according to the above aspect, preferably, it further includes a fragile member having a lower rigidity than each of the case and the at least one power storage cell. The fragile portion is formed by disposing a fragile member between the at least one power storage cell and the at least one fixing portion. With this configuration, a fragile portion can be easily formed between the at least one power storage cell and the at least one fixing portion by disposing the fragile member.

[0009] In this case, preferably, the fragile member includes a hollow member. With this configuration, the hollow member can be easily broken starting from the hollow space of the hollow member.

[0010] In the power storage device in which the fragile member is disposed, preferably, the fragile member is provided separately from each of the at least one power storage cell and the case. With this configuration, even if the fragile member is broken, it is possible to suppress the power storage cell and the case from being broken.

[0011] The power storage device in which the fragile member is disposed preferably includes an insulating film provided so as to wrap the at least one power storage cell together with the fragile member. With this configuration, since the fragile member and the power storage cell are integrally held by the insulating film, the fragile member can be easily fixed to the power storage cell. As a result, the at least one power storage cell and the fragile member can be handled as one unit. Thereby, the manufacturing process (assembly process) of the power storage device can be simplified.

[0012] The power storage device in which the fragile member is disposed preferably includes a cooling device that cools the at least one power storage cell, and the case includes the cooling device. The fragile member is fixed to the cooling device. With such a configuration, while the fragile member forms a fragile portion, the power storage cell can be cooled by the cooling device.

[0013] The power storage device in which the fragile member is disposed preferably has a fracture starting portion provided in the fragile member as a starting point of fracture. With such a configuration, the fragile member can be easily fractured starting from the fracture starting portion. As a result, the at least one fixing portion can be more easily peeled off from the at least one power storage cell.

[0014] In the power storage device according to the one aspect, preferably, the at least one power storage cell includes a plurality of power storage cells. The fragile portion is formed between each of the plurality of power storage cells and the at least one fixing portion. With such a configuration, the case can be easily peeled off from each of the plurality of power storage cells.

[0015] In the power storage device according to the one aspect, preferably, the at least one power storage cell includes a plurality of power storage cells. The plurality of power storage cells are arranged side by side in a first direction. The fragile portion is formed to extend in the first direction so as to span the region where the plurality of power storage cells are arranged. With such a configuration, the case can be peeled off from the plurality of power storage cells starting from one fragile portion. As a result, compared with the case where fragile portions are provided at positions corresponding to each of the plurality of power storage cells, the number of fragile portions can be reduced. As a result, it is possible to suppress the rigidity of the power storage device from becoming excessively low.

[0016] In the power storage device according to the above-described one aspect, preferably, the case includes a bottom surface that supports the at least one power storage cell from below and an upper surface that is provided so as to cover the at least one power storage cell from above. The at least one fixing portion includes at least one of the bottom surface and the upper surface. With this configuration, due to the fragile portion, at least one of the bottom surface and the upper surface can be easily peeled off from the power storage cell.

[0017] In the power storage device according to the above-described one aspect, preferably, the at least one power storage cell has a prismatic shape formed so as to extend in the second direction. The fragile portion is formed so as to extend in the second direction along the at least one power storage cell. With this configuration, the fragile portion can be made larger (longer) compared to the case where the fragile portion does not extend in the second direction in which the power storage cell extends. As a result, the case can be peeled off from the power storage cell even more easily.

Advantages of the Invention

[0018] According to the present disclosure, the power storage cell can be easily removed from the case to which the power storage cell is fixed.

Brief Description of the Drawings

[0019]

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[0020] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and their descriptions are not repeated.

[0021] In this specification, the vertical direction is the Z direction. Specifically, the upper side is the Z1 side and the lower side is the Z2 side. Each of the X direction and the Y direction is a direction orthogonal to the Z direction (i.e., the horizontal direction). The X direction is orthogonal to the Y direction. The X direction and the Y direction are examples of the "first direction" and the "second direction" of the present disclosure, respectively.

[0022] FIG. 1 is a perspective view showing the configuration of a power storage device 100 according to the present embodiment. The power storage device 100 is a device for storing power for driving an electric vehicle (not shown), for example. The X direction shown in FIG. 1 is, for example, the front-rear direction of the electric vehicle. The Y direction is the left-right direction of the electric vehicle.

[0023] The power storage device 100 includes a plurality (two in the present embodiment) of power storage modules 10 and a case 20. The number of power storage modules 10 is not limited to the above example. One power storage module 10 or three or more power storage modules 10 may be provided.

[0024] FIG. 2 is a cross-sectional view of the power storage module 10. Each of the plurality of power storage modules 10 includes a plurality of power storage cells 11. Each of the plurality of power storage cells 11 is formed to extend in the Y direction. The plurality of power storage cells 11 are arranged side by side in the X direction. Each of the plurality of power storage cells 11 may be arranged to extend in the X direction.

[0025] FIG. 3 is a perspective view showing the configuration of the storage battery cell 11. The storage battery cell 11 has a prismatic shape formed to extend in the Y direction. Specifically, the storage battery cell 11 has a length L1 in the Y direction. The storage battery cell 11 has a length L2 in the X direction. The length L1 is larger than the length L2. Also, the storage battery cell 11 has a height H in the Z direction. The length L1 is larger than the height H. Note that in FIG. 3, only one storage battery cell 11 and a hollow member 60 described later are shown for simplicity.

[0026] Referring again to FIG. 1, the case 20 houses a plurality of power storage modules 10. The case 20 includes an upper case 21, a lower case 22, and a cooling plate 23. The plurality of power storage modules 10 are housed in a space formed by assembling the upper case 21 to the lower case 22. The cooling plate 23 is also housed in the above space. Note that the cooling plate 23 is an example of the "cooling device" and the "fixing part" of the present disclosure.

[0027] The upper case 21 is provided to cover the plurality of power storage modules 10 from the Z1 side. The upper case 21 has an upper surface 21a and a plurality (for example, four) of side surfaces 21b. The upper surface 21a is provided to face the plurality of power storage modules 10 in the Z direction. Each of the plurality of side surfaces 21b is connected to the upper surface 21a. Specifically, each of the plurality of side surfaces 21b is provided to extend from the outer peripheral edge of the upper surface 21a to the Z2 side. The plurality of power storage modules 10 are arranged at positions surrounded by the plurality of side surfaces 21b when viewed from the Z1 side. Note that the upper case 21 is formed of, for example, resin.

[0028] The lower case 22 is provided to support a plurality of power storage modules 10 from the Z2 side. The lower case 22 has a bottom surface 22a (see FIG. 4) and a plurality of side surfaces 22b. The bottom surface 22a is provided to face the plurality of power storage modules 10 in the Z direction. Each of the plurality of side surfaces 22b is connected to the bottom surface 22a. Specifically, the plurality of side surfaces 22b are provided to extend from the outer peripheral edge of the bottom surface 22a to the Z1 side. The plurality of power storage modules 10 are arranged at positions surrounded by the plurality of side surfaces 22b when viewed from the Z1 side. The upper case 21 is assembled to the lower case 22 by connecting the side surface 21b of the upper case 21 to the side surface 22b of the lower case 22. Note that the bottom surface 22a is an example of the "fixing portion" of the present disclosure.

[0029] The cooling plate 23 is provided to cover the plurality of power storage modules 10 from the Z1 side. Specifically, the cooling plate 23 is provided between the upper surface 21a of the upper case 21 and the plurality of power storage modules 10. The cooling plate 23 is provided with a flow path 23a (see FIG. 4) through which a coolant flows. Each of the plurality of power storage modules 10 is cooled by the coolant flowing through the flow path 23a of the cooling plate 23.

[0030] The power storage device 100 includes a relay box 30. The relay box 30 is arranged on the X1 side with respect to the power storage module 10 on the X1 side. The relay box 30 houses a plurality of relays that control the on / off of the current flowing from the outside of the power storage device 100 to the power storage device 100 (or the current flowing from the power storage device 100 to the outside). Note that the relay box 30 is also housed in the case 20.

[0031] FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. 1. As shown in FIG. 4, each of the plurality of power storage cells 11 is wrapped by an insulating film 40. Thereby, the power storage cells 11 adjacent to each other in the X direction are isolated by the insulating film 40.

[0032] Each of the plurality of insulating films 40 is fixed to the cooling plate 23. Specifically, the space between the end portion on the Z1 side of each of the plurality of insulating films 40 and the cooling plate 23 is filled with an adhesive 50. Thereby, each of the plurality of power storage cells 11 is indirectly fixed to the cooling plate 23 via the insulating film 40.

[0033] Each of the plurality of insulating films 40 is fixed to the bottom surface 22a of the lower case 22. Specifically, the space between the end portion on the Z2 side of each of the plurality of insulating films 40 and the bottom surface 22a is filled with an adhesive 50. That is, each of the plurality of power storage cells 11 is indirectly fixed to the bottom surface 22a via the insulating film 40.

[0034] Here, when recycling the power storage cell or the like, it is necessary to remove the power storage cell from the case. However, in the conventional power storage device, since the power storage cell is adhered to the case, it is difficult to remove the power storage cell.

[0035] Therefore, in the present embodiment, a hollow member 60 is disposed between each of the plurality of power storage cells 11 and the cooling plate 23. The hollow member 60 has lower rigidity than each of the power storage cell 11 and the case 20. Thereby, the hollow member 60 is more likely to break than each of the power storage cell 11 and the case 20. As a result, by breaking the hollow member 60, it is possible to easily peel the cooling plate 23 from the plurality of power storage cells 11. Note that the hollow member 60 is an example of the "fragile member" of the present disclosure.

[0036] Further, in the present embodiment, the hollow member 60 is also disposed between each of the plurality of power storage cells 11 and the bottom surface 22a of the lower case 22.

[0037] Therefore, in the present embodiment, a fragile portion is formed between each of the plurality of power storage cells 11 and each of the cooling plate 23 and the bottom surface 22a so that the hollow member 60 is disposed at the above positions.

[0038] The hollow member 60 is provided separately from each of the plurality of power storage cells 11. Further, the hollow member 60 is provided separately from the case 20. Specifically, the hollow member 60 is fixed to each of the plurality of power storage cells 11. Note that the hollow member 60 is not in direct contact with the case 20.

[0039] Specifically, the hollow member 60 is disposed on each of the end faces 11a on the Z1 side and the end faces 11b on the Z2 side of each of the plurality of power storage cells 11. Each of the end faces 11a and 11b and the hollow member 60 are adhered by an adhesive or the like. Note that the hollow member 60 may be merely disposed on each of the end faces 11a and 11b without being adhered by an adhesive or the like.

[0040] Each of the plurality of insulating films 40 is provided so as to wrap the power storage cell 11 together with the hollow member 60. Specifically, each of the plurality of insulating films 40 integrally wraps one power storage cell 11, the hollow member 60 disposed on the end face 11a of the one power storage cell 11, and the hollow member 60 disposed on the end face 11b of the one power storage cell 11. Note that each of the plurality of insulating films 40 wraps different power storage cells 11.

[0041] As described above, the adhesive 50 adheres the insulating film 40 and the case 20 (cooling plate 23, bottom surface 22a). Therefore, the hollow member 60 is fixed to the case 20 (cooling plate 23, bottom surface 22a) indirectly via the insulating film 40 by the adhesive 50.

[0042] Although not shown, each of the plurality of insulating films 40 is formed to extend in the Y direction, similar to the power storage cell 11. Thereby, it is possible to more reliably isolate adjacent power storage cells 11 by the insulating film 40. Note that at least one of the Y1 side and the Y2 side of the power storage cell 11 (hollow member 60) may be covered by the insulating film 40.

[0043] Referring again to FIG. 3, the hollow member 60 is formed to extend in the Y direction along the power storage cell 11. Specifically, the hollow member 60 has a prismatic shape extending in the Y direction. A through hole 61 extending in the Y direction is formed in the hollow member 60. The opening of the through hole 61 has, for example, a rectangular shape. Note that the above opening may have other shapes (for example, a circular shape). Also, the hollow member 60 may have, for example, a cylindrical shape.

[0044] The hollow member 60 has a length L11 in the Y direction. The hollow member 60 has a length L12 in the X direction. The length L11 is greater than the length L12. The length L11 of the hollow member 60 in the Y direction is smaller than the length L1 of the power storage cell 11 in the Y direction. The length L12 of the hollow member 60 in the X direction is smaller than the length L2 of the power storage cell 11 in the X direction. Note that the relationship between the sizes of the hollow member 60 and the power storage cell 11 is not limited to the above example.

[0045] A notch 62 serving as a starting point for breakage is provided in the hollow member 60. Further, the power storage device 100 is provided with a peeling fitting 70 (see FIG. 1) disposed at a position in the Z direction corresponding to the notch 62 of the hollow member 60 on the Z1 side. The peeling fitting 70 is attached to the side surface on the X1 side of each power storage module 10. The peeling fitting 70 is provided to extend in the Y direction along the above side surface. For example, when the peeling fitting 70 is held by a jig (device) not shown and moved to the X2 side by the jig (device), the hollow member 60 is cut starting from the notch 62. Thereby, the upper case 21 is peeled from the power storage module 10. Also, the peeling fitting 70 also serves as an index (mark) for the cutting position of the hollow member 60. Note that the peeling fitting 70 may also be disposed at a position in the Z direction corresponding to the notch 62 of the hollow member 60 on the Z1 side. Note that the notch 62 is an example of the "break starting portion" of the present disclosure.

[0046] As described above, in the present embodiment, a hollow member 60 is disposed between each of the plurality of power storage cells 11 and the case 20 (the cooling plate, the bottom surface 22a of the lower case 22). Thereby, by breaking the hollow member 60 having relatively low mechanical strength, the power storage cell 11 can be peeled from the case 20 (the cooling plate, the bottom surface 22a). As a result, the case 20 can be peeled from the power storage cell 11 with a relatively small force, so that the peeling process can be simplified. Further, the device (fixture) used for the peeling can be miniaturized (simplified). Therefore, the power storage cell 11 can be easily removed from the case 20.

[0047] In the above embodiment, an example in which the hollow member 60 is provided for each power storage cell 11 is shown, but the present disclosure is not limited to this. The hollow member 60 may not be provided for each power storage cell 11.

[0048] For example, as in the example shown in FIG. 5, the hollow member 60 is provided across a region where a plurality (two in FIG. 5) of power storage cells 11 are arranged. In other words, the hollow member 60 is arranged so as to straddle the end faces 11a (end faces 11b) of the plurality of power storage cells 11 arranged side by side in the X direction. In this case, as shown in FIG. 5, the insulating film 40 is not provided.

[0049] Further, as a modification of FIG. 5, on one of the Z1 side and the Z2 side, the hollow member 60 may be arranged so as to straddle a plurality of power storage cells 11, and on the other of the Z1 side and the Z2 side, the hollow member 60 may be arranged for each power storage cell 11. Further, the plurality of power storage cells 11 and the hollow member 60 may be wrapped by one insulating film. Further, the number of power storage cells 11 straddled by the hollow member 60 may be three or more.

[0050] In the above embodiment, an example in which the power storage cell 11 and the hollow member 60 are integrally wrapped by the insulating film 40 is shown, but the present disclosure is not limited to this. The insulating film 40 may not be provided.

[0051] In the above-described embodiment, an example in which the power storage cell 11 (insulating film 40) is fixed to the cooling plate 23 has been shown. However, the present disclosure is not limited to this. The cooling plate 23 may not be disposed on the Z1 side of the power storage cell 11.

[0052] In the example shown in FIG. 6, each of a plurality of power storage cells 11 (insulating films 40) is fixed to the upper surface 21a of the upper case 21 by an adhesive 50. Further, a cooling plate 123 is provided between the bottom surface 22a of the lower case 22 and the plurality of power storage cells 11 (insulating films 40). A flow path 123a through which a coolant flows is formed in the cooling plate 123. In this case, each of the upper surface 21a and the cooling plate 123 is an example of the "fixing portion" of the present disclosure.

[0053] Note that the cooling plate may not be provided on either the Z1 side or the Z2 side of the power storage cell 11.

[0054] In the above-described embodiment, an example in which a hollow member 60 is disposed between the power storage cell 11 and the case 20 to form a vulnerable portion between the power storage cell 11 and the case 20 has been shown. However, the present disclosure is not limited to this. A vulnerable portion may be formed without disposing a vulnerable member such as the hollow member 60.

[0055] In the example shown in FIG. 7, instead of disposing the hollow member 60, a plurality of power storage cells 11 and the case 20 (the bottom surface 22a of the cooling plate 23 and the lower case 22) are adhered by an adhesive 150 in which air bubbles 151 are formed. The air bubbles 151 are formed between each of the plurality of power storage cells 11 and the case 20 (the cooling plate 23 and the bottom surface 22a). As a result, a vulnerable portion of the adhesive 150 is formed due to the formation of the air bubbles 151. The air bubbles 151 may extend in the X direction so as to span the region where the plurality of power storage cells 11 are disposed. In the example shown in FIG. 7, the insulating film 40 is not provided. The air bubbles 151 are an example of the "vulnerable portion" of the present disclosure.

[0056] In the above-described embodiment, an example in which the hollow member 60 is provided separately from each of the power storage cell 11 and the case 20 has been shown, but the present disclosure is not limited to this. The hollow member 60 may be integrally formed with the power storage cell 11 or the case 20.

[0057] In the example shown in FIG. 8, the hollow portion is integrally formed with the case. The upper case 121 includes an upper surface 121a and a plurality of hollow portions 121b. The plurality of hollow portions 121b are integrally formed with the upper surface 121a. Specifically, each of the plurality of hollow portions 121b is provided so as to protrude from the upper surface 121a toward the power storage cell 11. A notch 121c is provided in the hollow portion 121b. Although not shown, the hollow portion may be integrally formed with the lower case, or the hollow portion may be integrally formed with both the upper case and the lower case. In the case of the example shown in FIG. 8, the upper surface 121a is an example of the "fixing portion" of the present disclosure. Further, the hollow portion 121b is an example of the "fragile portion" of the present disclosure.

[0058] In the example shown in FIG. 9, the power storage cell is integrally formed with the hollow member. The power storage cell 111 is integrally formed with the hollow member 160. Specifically, the hollow member 160 is provided so as to protrude from the power storage cell 111 toward the Z1 side. A notch 161 is provided in the hollow member 160. Although not shown, the hollow member 160 may be provided so as to protrude from the power storage cell 111 toward the Z2 side. The hollow member 160 may be provided so as to protrude from both the Z1 side and the Z2 side of the power storage cell 111. The hollow member 160 and the notch 161 are examples of the "fragile member" and the "fracture starting point portion" of the present disclosure, respectively.

[0059] In the above-described embodiment, an example in which a fragile portion is formed by arranging the hollow member 60 has been shown, but the present disclosure is not limited to this. For example, a fragile portion may be formed by arranging a member that is not hollow but has a relatively low mechanical strength.

[0060] In the above embodiment, an example in which a plurality of power storage cells 11 are provided in the power storage module 10 has been shown, but the present disclosure is not limited thereto. For example, the power storage module may have only one power storage cell (for example, a laminated battery).

[0061] In the above embodiment, an example in which a notch is provided as a fracture initiation point in the hollow member has been shown, but the present disclosure is not limited thereto. For example, other than a notch (for example, a hole) may be provided as the fracture initiation point. Further, a fracture initiation point such as a notch may not be provided in the hollow member.

[0062] In the above embodiment, an example in which the hollow member 60 is disposed on each of the Z1 side and the Z2 side of the power storage cell 11 has been shown, but the present disclosure is not limited thereto. The hollow member 60 may be disposed on only one of the Z1 side and the Z2 side of the power storage cell 11.

[0063] Note that the configurations (processes) of the above embodiment and each of the above modification examples may be combined with each other.

[0064] The embodiments disclosed this time should be considered as illustrative in all respects and not restrictive. The scope of the present disclosure is shown by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope equivalent to the claims.

Description of Reference Numerals

[0065] 11, 111 Power storage cell, 20 Case, 21a, 121a Upper surface, 22a Bottom surface (fixed portion), 23, 123 Cooling plate (cooling device) (fixed portion), 40 Insulating film, 50, 150 Adhesive, 60, 160 Hollow member (fragile member), 62, 161 Notch (fracture initiation point), 100 Power storage device, 121b Hollow portion (fragile portion), 151 Bubble (fragile portion), X direction (first direction), Y direction (second direction).

Claims

1. At least one power storage cell, A case for housing the at least one power storage cell, and The case includes at least one fixing portion fixed to the at least one power storage cell, A power storage device in which a fragile portion is formed between the at least one power storage cell and the at least one fixing portion.

2. Further comprising a fragile member having a lower rigidity than each of the case and the at least one power storage cell, The power storage device according to claim 1, wherein the fragile portion is formed by disposing the fragile member between the at least one power storage cell and the at least one fixing portion.

3. The power storage device according to claim 2, wherein the fragile member includes a hollow member.

4. The power storage device according to claim 2 or 3, wherein the fragile member is provided separately from each of the at least one power storage cell and the case.

5. The power storage device according to claim 2 or 3, further comprising an insulating film provided so as to wrap the at least one power storage cell together with the fragile member.

6. The case includes a cooling device for cooling the at least one power storage cell, The power storage device according to claim 2 or 3, wherein the fragile member is fixed to the cooling device.

7. The power storage device according to claim 2 or 3, wherein a fracture starting portion serving as a starting point of fracture is provided in the fragile member.

8. The at least one power storage cell includes a plurality of power storage cells, The power storage device according to any one of claims 1 to 3, wherein the fragile portion is formed between each of the plurality of power storage cells and the at least one fixing portion.

9. The at least one power storage cell includes a plurality of power storage cells, The plurality of power storage cells are arranged side by side in a first direction, The power storage device according to any one of claims 1 to 3, wherein the fragile portion is formed to extend in the first direction so as to be provided across the region where the plurality of power storage cells are arranged.

10. The case includes a bottom surface that supports the at least one power storage cell from below and an upper surface that is provided so as to cover the at least one power storage cell from above, The power storage device according to any one of claims 1 to 3, wherein the at least one fixing portion includes at least one of the bottom surface and the upper surface.

11. The at least one power storage cell has a prismatic shape formed to extend in a second direction, The power storage device according to any one of claims 1 to 3, wherein the vulnerable portion is formed to extend in the second direction along the at least one power storage cell.

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