Battery pack

Abstract

To provide a battery pack capable of suppressing a decrease in energy density and suppressing displacement of a power storage device due to impact.SOLUTION: A battery pack includes: an electrode body in which bipolar electrodes are stacked with separators interposed therebetween; a plurality of power storage devices having resin frames surrounding the side surfaces of the electrode body; and a plurality of current collector plates, which are alternately stacked. The power storage devices have a plurality of convex portions protruding from one side and the other side in the stacking direction of the stack. The current collector plates have a plurality of fitting holes that fit into the convex portions. The current collector plates are respectively arranged at the bottom and top of the stack in the stacking direction and between the power storage devices adjacent in the stacking direction.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a battery pack.

Background Art

[0002] Patent Document 1 discloses a laminate in which a power storage module in which an electrode body is surrounded by a sealing body and a conductive plate are laminated.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In order to suppress displacement of the battery module with respect to an external impact, when the power storage module and the current collector plate are adhered and fixed, if the space for accommodating the current collector is the same, in the stacking direction of the laminate, the size of the battery module is reduced by the thickness of the adhesive, and the energy density decreases.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a battery pack that can suppress displacement of the power storage device with respect to an impact while suppressing a decrease in energy density.

Means for Solving the Problems

[0006] In order to solve the above-described problems and achieve the object, a battery pack according to the present invention includes a plurality of power storage devices having an electrode body in which bipolar electrodes are stacked via separators and a resin frame surrounding the side surfaces of the electrode body, and a plurality of current collector plates, and is a battery pack including a laminate in which the plurality of power storage devices and the plurality of current collector plates are alternately stacked. The power storage device has a plurality of convex portions protruding respectively on one side and the other side in the stacking direction of the laminate. The current collector plate has a plurality of fitting holes that fit with the convex portions. The current collector plate is disposed at the lowermost part and the uppermost part of the laminate in the stacking direction, and between the power storage devices adjacent to each other in the stacking direction, respectively.

Advantages of the Invention

[0007] The battery pack according to the present invention has an effect that it can suppress a decrease in energy density and suppress displacement of the power storage device with respect to impact.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments of a battery pack according to the present invention will be described. Note that the present invention is not limited by the present embodiment.

[0010] FIG. 1 is a cross-sectional view showing a schematic configuration of a battery pack 1 according to an embodiment. In the embodiment, the battery pack 1 is mounted on an electric vehicle and is, for example, a power supply source that supplies power to a motor that is a drive source of the electric vehicle. In the battery pack 1 according to the embodiment, a battery stack 2 is constrained by a constraint component 3 and is housed in a case (not shown).

[0011] The battery stack 2 includes a plurality of battery modules 21a, 21b, 21c, 21d which are power storage devices, a plurality of current collector plates 22a, 22b, 22c, and a plurality of cooling plates 23a, 23b, etc. The battery stack 2 is a laminate formed by stacking, in the stacking direction which is the same as the height direction (vertical direction) of the battery pack 1, from the lower side to the upper side, the current collector plate 22a, the battery module 21a, the cooling plate 23a, the battery module 21b, the current collector plate 22b, the battery module 21c, the cooling plate 23b, the battery module 21d, and the current collector plate 22c in this order. In the battery stack 2 according to the embodiment, the current collector plates 22a, 22b, 22c are respectively arranged at the lowermost part and the uppermost part of the battery stack 2 in the stacking direction and between the adjacent battery modules 21b, 21c in the stacking direction. Further, in the battery stack 2 according to the embodiment, the cooling plates 23a, 23b are arranged between the adjacent battery modules 21a, 21b in the stacking direction and between the adjacent battery modules 21c, 21d in the stacking direction. And the battery stack 2 is constrained by being sandwiched from the upper side and the lower side in the stacking direction by the restraining component 3.

[0012] In addition, in this embodiment, when the battery modules 21a, 21b, 21c, 21d are not particularly distinguished, they are simply referred to as the battery module 21. In addition, in this embodiment, for the components corresponding to each of the battery modules 21a, 21b, 21c, 21d, "a", "b", "c", "d" are appended after the number of the reference numeral. Also, in this embodiment, when the current collector plates 22a, 22b, 22c are not particularly distinguished, they are simply referred to as the current collector plate 22. In addition, in this embodiment, for the components corresponding to each of the current collector plates 22a, 22b, 22c, "a", "b", "c" are appended after the number of the reference numeral. Also, in this embodiment, when the cooling plates 23a, 23b are not particularly distinguished, they are simply referred to as the cooling plate 23. In addition, in this embodiment, for the components corresponding to each of the cooling plates 23a, 23b, "a", "b" are appended after the number of the reference numeral.

[0013] FIG. 2 is a perspective view showing the appearance of the battery module 21 according to the embodiment. The battery module 21 according to the embodiment is configured in a plate shape by an electrode body in which bipolar electrodes are stacked via separators, a sealing body 212 that seals the electrode body, and the like. In the electrode body, the bipolar electrodes are stacked in the same direction as the stacking direction of the battery modules 21 in the battery stack 2. The sealing body 212 has a resin frame 213 that surrounds the side surface of the electrode body. The battery module 21 according to the embodiment has a plurality of convex portions 214 that protrude upward (one side) and downward (the other side) in the stacking direction. Specifically, a plurality of convex portions 214 that protrude upward and downward in the stacking direction are provided at the upper end and the lower end of the resin frame 213 in the stacking direction. The convex portion 214 has a rectangular shape when viewed from above or below in the stacking direction. The plurality of convex portions 214 are arranged at regular intervals in the longitudinal direction of the resin frame 213 (along the side of the battery module 21) so that the convex portions 214 protruding upward in the stacking direction and the convex portions 214 protruding downward in the stacking direction are paired.

[0014] In the battery pack 1 according to the embodiment, the current collector plate 22 has a plurality of fitting holes 221 that fit with the plurality of convex portions 214 of the battery module 21. Further, in the battery pack 1 according to the embodiment, the cooling plate 23 has a plurality of fitting holes 231 that fit with the plurality of convex portions 214 of the battery module 21.

[0015] FIG. 3 is a diagram showing a connection method in the battery stack 2. In FIG. 3, a part of the battery stack 2 is shown in an exploded state, and a connection method when stacking the cooling plate 23a, the battery module 21b, the current collector plate 22b, the battery module 21c, and the cooling plate 23b will be described. In FIG. 3, reference numeral 212c is the sealing body of the battery module 21c, and reference numeral 213c is the resin frame of the battery module 21c. Further, in FIG. 3, reference numeral 212b is the sealing body of the battery module 21b, and reference numeral 213b is the resin frame of the battery module 21b.

[0016] On the peripheral portion of the current collector plate 22b, a plurality of convex portions 214b protruding upward in the stacking direction of the battery module 21b, and a plurality of convex portions 214c protruding downward in the stacking direction of the battery module 21c, and a plurality of fitting holes 221b that respectively fit thereinto are provided in a row along each side of the current collector plate 22b. The fitting hole 221b has a rectangular opening with substantially the same size as the rectangular convex portions 214b, 214c when viewed from above or below in the stacking direction. Then, by fitting the plurality of convex portions 214b protruding upward in the stacking direction of the battery module 21b and the plurality of fitting holes 221b of the current collector plate 22b, the battery module 21b and the cooling plate 23a are connected. Further, by fitting the plurality of convex portions 214c protruding downward in the stacking direction of the battery module 21c and the plurality of fitting holes 231a of the current collector plate 22b, the battery module 21c and the current collector plate 22b are connected. Note that the plurality of convex portions 214b protruding upward in the stacking direction of the battery module 21b and the plurality of convex portions 214c protruding downward in the stacking direction of the battery module 21c are alternately fitted to the plurality of fitting holes 221b arranged in a row on each side of the current collector plate 22b.

[0017] On the peripheral edge of the cooling plate 23a, a plurality of convex portions 214a protruding upward in the stacking direction of a battery module 21a (not shown), a plurality of convex portions 214b protruding downward in the stacking direction of the battery module 21b, and a plurality of fitting holes 231a respectively fitted thereto are provided in a row along each side of the cooling plate 23a. The fitting holes 231a are rectangularly opened with substantially the same size as the rectangular convex portions 214a, 214b when viewed from above or below in the stacking direction. Then, when the plurality of convex portions 214a protruding upward in the stacking direction of the battery module 21a (not shown) are fitted with the plurality of fitting holes 231a of the cooling plate 23a, the battery module 21a and the cooling plate 23a are connected. Also, when the plurality of convex portions 214b protruding downward in the stacking direction of the battery module 21b are fitted with the plurality of fitting holes 231a of the cooling plate 23a, the battery module 21b and the cooling plate 23a are connected. Incidentally, the plurality of convex portions 214a protruding upward in the stacking direction of the battery module 21a (not shown) and the plurality of convex portions 214b protruding downward in the stacking direction of the battery module 21b are alternately fitted to the plurality of fitting holes 231a arranged in a row on each side of the cooling plate 23a.

[0018] On the peripheral edge of the cooling plate 23b, a plurality of convex portions 214c protruding upward in the stacking direction of the battery module 21c and a plurality of convex portions 214d protruding downward in the stacking direction of a battery module 21d (not shown) are respectively fitted with a plurality of fitting holes 231b provided in a row along each side of the cooling plate 23b. The fitting holes 231b are rectangularly opened with substantially the same size as the rectangular convex portions 214c, 214d when viewed from above or below in the stacking direction. Then, the battery module 21c and the cooling plate 23b are connected by fitting the plurality of convex portions 214c protruding upward in the stacking direction of the battery module 21c and the plurality of fitting holes 231b of the cooling plate 23b. Also, the battery module 21d and the cooling plate 23b are connected by fitting the plurality of convex portions 214d protruding downward in the stacking direction of a battery module 21d (not shown) and the plurality of fitting holes 231b of the cooling plate 23b. Incidentally, the plurality of convex portions 214c protruding upward in the stacking direction of the battery module 21c and the plurality of convex portions 214d protruding downward in the stacking direction of a battery module 21d (not shown) are alternately fitted to the plurality of fitting holes 231b arranged in a row on each side of the cooling plate 23b.

[0019] Similarly, at the peripheral edge of a current collector plate 22a (not shown) disposed at the lowermost part of the battery stack 2, a plurality of fitting holes 221a that fit with a plurality of convex portions 214a protruding downward in the stacking direction of a battery module 21a (not shown) are provided in a row along each side of the current collector plate 22a. Then, the battery module 21a and the current collector plate 22a are connected by fitting the plurality of convex portions 214a protruding downward in the stacking direction of the battery module 21a (not shown) and the plurality of fitting holes 221a of the current collector plate 22a (not shown). Further, at the peripheral edge of a current collector plate 22c (not shown) disposed at the uppermost part of the battery stack 2, a plurality of fitting holes 221c that fit with a plurality of convex portions 214d protruding upward in the stacking direction of a battery module 21d (not shown) are provided in a row along each side of the current collector plate 22c. Then, the battery module 21d and the current collector plate 22c are connected by fitting the plurality of convex portions 214d protruding upward in the stacking direction of the battery module 21d (not shown) and the plurality of fitting holes 221c of the current collector plate 22c (not shown).

[0020] In this embodiment, when the convex portions 214a, 214b, 214c, and 214d of the battery modules 21a, 21b, 21c, and 21d are not particularly distinguished, they are simply referred to as convex portion 214. Also, in this embodiment, when the fitting holes 221a, 221b, and 221c of the current collector plates 22a, 22b, and 22c are not particularly distinguished, they are simply referred to as fitting hole 221. Further, in this embodiment, when the fitting holes 231a and 231b of the plurality of cooling plates 23a and 23b are not particularly distinguished, they are simply referred to as fitting hole 231.

[0021] In the battery pack 1 according to the embodiment, a plurality of convex portions 214 provided on the resin frame 213 (side surface) of the battery module 21 are fitted into a plurality of fitting holes 221 provided on the peripheral portion of the current collector plate 22 or a plurality of fitting holes 231 provided on the peripheral portion of the cooling plate 23, whereby the battery module 21, the current collector plate 22, and the cooling plate 23 are connected and laminated in the stacking direction. Thereby, due to the fitting of the convex portions 214 and the fitting holes 221, 231, displacement of the battery module 21 in a direction (horizontal direction) orthogonal to the stacking direction (vertical direction) can be suppressed. Therefore, the restraining force required for restraining the battery module 21 by the restraining component 3 becomes small. For example, the thickness of the portion of the restraining component 3 pressing the battery stack 2 from above in the stacking direction can be reduced and simplified. As a result, when the accommodation space in the case of the battery pack 1 is the same, the size of the battery module 21 in the stacking direction can be increased by the amount of the reduction in the thickness of the restraining component 3 in the stacking direction, so that the energy density of the battery pack 1 can be increased. Further, when an adhesive is used for fixing the battery module 21 and the current collector plate 22 or for fixing the battery module 21 and the cooling plate 23, the thickness of the adhesive can be reduced by the amount of the reduction in the restraining force, and the size of the battery module 21 in the stacking direction can be increased to increase the energy density. Further, since the amount of the adhesive used can be reduced, cost reduction can be achieved.

[0022] As described above, in the battery pack 1 according to the embodiment, when the space for accommodating the battery stack 2 is the same, the size of the battery module 21 is reduced by the thickness of the restraining component 3 and the adhesive in the stacking direction of the battery stack 2, and while suppressing a decrease in the energy density, displacement of the battery stack 2 with respect to an impact can be suppressed.

Description of Reference Numerals

[0023] 1 Battery pack 2 Battery stack 3 Restraining component 21 Battery module 22 Current collector plate 23 Cooling plate 212 Sealing body 213 Resin frame 214 Convex part 221, 231 Fitting holes

Claims

【Claim 1】 A battery pack comprising a laminate in which a plurality of power storage devices having an electrode body in which bipolar electrodes are laminated via a separator and a resin frame surrounding the side surfaces of the electrode body, and a plurality of current collector plates are alternately laminated, wherein the power storage device has a plurality of convex portions protruding respectively on one side and the other side in the lamination direction of the laminate, the current collector plate has a plurality of fitting holes that fit with the convex portions, and the current collector plate is disposed at the lowermost and uppermost portions of the laminate in the lamination direction and between the power storage devices adjacent to each other in the lamination direction, respectively.

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