Power storage device and battery pack structure

Abstract

To provide a power storage device and a battery pack structure that is resistant against flexural stress.SOLUTION: A power storage device according to the present disclosure includes a multilayer body including a plurality of metal plates that are stacked, and a sealing body for sealing an internal space formed between two adjacent metal plates of the plurality of metal plates. The metal plates include a first metal plate, which is a positive electrode terminal electrode, a second metal plate, which is a negative electrode terminal electrode, and a plurality of third metal plates, which are a plurality of bipolar electrodes provided between the first metal plate and the second metal plate. Each of the bipolar electrodes includes a voltage detection terminal. Each of the third metal plates includes a positive electrode applied on one surface of the third metal plate and a negative electrode applied on the other surface of the third metal plate and has a support member in the internal space.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an electricity storage device and a battery pack structure. [Background technology]

[0002] Patent Document 1 discloses an electricity storage module in which a plurality of bipolar electrodes are stacked. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-174632 Summary of the Invention [Problem to be solved by the invention]

[0004] A bipolar electrode has a structure in which a positive electrode is formed on one side of a metal plate serving as a current collector, and a negative electrode is formed on the other side. The positive electrode and the negative electrode can be easily formed by coating the metal plate with an active material.

[0005] On the other hand, if there are areas of the metal plate that are not coated (uncoated areas), buckling may occur in the uncoated areas due to the weight of the metal plate when multiple bipolar electrodes are stacked. Furthermore, if thermal stress is repeatedly applied to the energy storage module due to temperature changes, the buckled metal plate may break.

[0006] The present disclosure has been made to solve such problems, and has an object to provide an electricity storage device and battery pack structure that are resistant to bending stress. [Means for solving the problem]

[0007] The present disclosure provides an energy storage device comprising: a laminate having a plurality of stacked metal plates; and a seal for sealing an internal space formed between two adjacent metal plates, the plurality of metal plates including a first metal plate serving as a positive terminal electrode, a second metal plate serving as a negative terminal electrode, and a plurality of third metal plates serving as bipolar electrodes disposed between the first and second metal plates, each of the plurality of bipolar electrodes including a voltage detection terminal, each of the plurality of third metal plates including a positive electrode coated on one side thereof and a negative electrode coated on the other side thereof, and a support member in the internal space, thereby providing an energy storage device resistant to bending stress.

[0008] The support member may be an insulating flat plate that is durable against bending stress, thereby making it possible to suppress buckling of the electricity storage device.

[0009] The support member may be an insulating dot print or a resin square bar provided in the center of the internal space, thereby making it possible to suppress buckling of the electricity storage device.

[0010] The support member may be formed in an area of ​​the third metal plate where the positive electrode and the negative electrode are not formed, thereby making it possible to suppress buckling of the electricity storage device.

[0011] Furthermore, the battery assembly structure according to the present disclosure is formed by stacking a plurality of power storage devices, thereby providing a battery assembly structure that is resistant to bending stress. [Effects of the Invention]

[0012] The present disclosure makes it possible to provide an electricity storage device and a battery pack structure that are resistant to bending stress. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a diagram illustrating a power storage device according to the present disclosure. [Figure 2] 10A and 10B are diagrams illustrating a support member of the power storage device according to the present disclosure. [Figure 3] FIG. 10 is a diagram illustrating a related power storage device. [Figure 4] 1A and 1B are diagrams illustrating buckling and fracture that occur in a forming device. DETAILED DESCRIPTION OF THE INVENTION

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Fig. 1(a) is a diagram illustrating a power storage device 10 according to the present embodiment.

[0015] The energy storage device 10 comprises a laminate having a plurality of stacked metal plates 100. The plurality of metal plates 100 are divided into a first metal plate 100A, which is a positive terminal electrode, a second metal plate 100B, which is a negative terminal electrode, and a plurality of third metal plates 100C, which constitute a plurality of bipolar electrodes 110 provided between the first and second metal plates. The metal plates are preferably made of Al, Cu, or the like. Furthermore, a battery assembly structure can be obtained by stacking a plurality of energy storage devices 10.

[0016] 1(a), the laminate has a first metal plate 100A, which is a positive terminal electrode, on the upper surface in the stacking direction, and a second metal plate 100B, which is a negative terminal electrode, on the lower surface in the stacking direction. However, the configuration of the laminate is not limited to this, and the positive terminal electrode and the negative terminal electrode may be disposed in a positional relationship opposite to that of the configuration in FIG. 1 in the stacking direction.

[0017] 1(b) is an enlarged view of a bipolar electrode 110. Each of the multiple bipolar electrodes 110 includes a third metal plate 100C, a positive electrode 111 formed on one surface of the third metal plate 100C, and a negative electrode 112 formed on the other surface of the third metal plate. The positive electrode 111 is formed by applying a positive electrode active material to one surface of the third metal plate 100C, and the negative electrode 112 is formed by applying a negative electrode active material to the other surface of the third metal plate.

[0018] Furthermore, it is preferable that a voltage detection terminal (not shown) is provided in the region (uncoated portion) of the bipolar electrode 110 where the positive electrode 111 and the negative electrode 112 are not formed, which facilitates quality control.

[0019] An internal space 120 is formed between two adjacent metal plates among the plurality of metal plates 100. As an example, Fig. 1 shows the internal space 120 formed between a first metal plate 100A and a third metal plate 100C adjacent to the first metal plate 100A.

[0020] The electricity storage device 10 according to the present disclosure includes sealants 121 and 122 for sealing the internal space 120, and a spacer 123 for maintaining the thickness of the laminate. The sealants 121 and 122 preferably have chemical resistance to the electrolyte solution (not shown) filled in the internal space 120, and are made of a resin material such as polypropylene, for example.

[0021] The power storage device 10 according to the present disclosure includes a support member 130 in the internal space 120. The support member 130 is preferably provided in an area (uncoated portion) of the third metal plate 100C where the positive electrode 111 and the negative electrode 112 are not formed.

[0022] The support member 130 is preferably an insulating flat plate that is durable against bending stress. As shown in Fig. 2, the support member 130 may be a dot print (see Fig. 2(a)) or a resin block (see Fig. 2(b)) provided in the center of the internal space 120. The dot print and the resin block are preferably insulating.

[0023] With this configuration, buckling due to the weight of the third metal plate 100C can be prevented, and therefore, an electricity storage device that is resistant to bending stress can be obtained.

[0024] As a comparative example, Fig. 3(a) shows the configuration of an electricity storage device that does not have a support member 130. Buckling may occur in the region (uncoated portion) where the positive electrode 111 and the negative electrode 112 are not formed in the third metal plate 100C of the bipolar electrode 110, causing the metal plate to break (see Fig. 3(b)).

[0025] The buckling and fracture mechanisms will be explained using Figure 4. Figures 4(a) and (b) are enlarged views of the corners of the power storage device shown in Figure 3, omitting the first metal plate 100A. The region of the third metal plate 100C where the positive electrode 111 and the negative electrode 112 are not formed (uncoated region) has a small moment of inertia. Furthermore, since the uncoated region extends in the vertical and horizontal directions in the plan view, this region is prone to buckling due to the weight of the metal plate itself (see Figure 4(a)).

[0026] Furthermore, since the sealants 121 and 122 are made of a resin material, they tend to expand and contract due to temperature changes in the energy storage device. For example, when a buckled energy storage device is cooled, stress acts in the direction of the arrows shown in Figure 4(b), causing buckling and shrinkage of the resin material, resulting in breakage.

[0027] The energy storage device 10 according to the present disclosure can prevent buckling due to the weight of the metal plate by providing an insulating flat plate that is durable against bending stress in the uncoated portion. Also, the energy storage device 10 according to the present disclosure can prevent buckling due to the weight of the metal plate by providing an insulating dot print or a resin square bar in the uncoated portion, which can compensate for the second moment of area of ​​the metal plate.

[0028] In this way, it is possible to provide an electricity storage device and a battery pack structure that are resistant to bending stress.

[0029] The present disclosure is not limited to the above-described embodiment, and can be modified as appropriate within the scope of the present disclosure. [Explanation of symbols]

[0030] 10. Energy storage device 100 metal plate 100A First Metal Plate 100B 2nd metal plate 100C 3rd metal plate 110 Bipolar Electrode 111 Positive electrode 112 Negative electrode 120 Interior Space 121, 122 Sealing body 123 Spacer 130 Support member

Claims

1. a laminate having a plurality of stacked metal plates; a seal for sealing an internal space formed between two adjacent metal plates among the plurality of metal plates, the plurality of metal plates include a first metal plate that is a positive terminal electrode, a second metal plate that is a negative terminal electrode, and a plurality of third metal plates that are a plurality of bipolar electrodes provided between the first metal plate and the second metal plate; Each of the plurality of bipolar electrodes includes a voltage detection terminal; each of the plurality of third metal plates has a positive electrode formed on one surface of the third metal plate and a negative electrode formed on the other surface of the third metal plate; A support member is provided in the internal space. Energy storage device.

2. The support member is an insulating flat plate having durability against bending stress. The power storage device according to claim 1 .

3. The support member is an insulating dot print or a resin square bar provided in the center of the internal space. The power storage device according to claim 1 .

4. the support member is formed in a region of the third metal plate where the positive electrode and the negative electrode are not formed; The electricity storage device according to any one of claims 1 to 3.

5. A battery pack structure in which a plurality of the electricity storage devices according to any one of claims 1 to 3 are stacked.

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