Power storage module

Abstract

To provide a power storage module that can discharge, to the outside, gas generated by an increase in the temperature of the laminate.SOLUTION: A power storage module according to the present disclosure includes: a laminate 10 in which a plurality of electrodes are stacked; a resin portion 30 provided on at least a portion of a side of the laminate 10 along an electrode stacking direction from a top surface U to a bottom surface L of the power storage module 1; and a sealing body 20 provided so as to surround the side of the laminate 10 and the resin portion 30. Therein a melting point of the resin portion 30 is lower than a melting point of the sealing body 20.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an energy storage module. [Background technology]

[0002] For example, as disclosed in Patent Document 1, there is known an energy storage device including one or more energy storage modules each including a laminate in which a plurality of electrodes are stacked. The energy storage module includes a laminate in which a plurality of bipolar electrodes are stacked with separators interposed therebetween. The laminate is then sealed and fixed at its periphery by a sealing material such as a sealing material or a potting material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-108243 Summary of the Invention [Problem to be solved by the invention]

[0004] The inventors have found the following problem with the electricity storage device disclosed in Patent Document 1. When the stack experiences thermal runaway, gas is generated from the stack. However, because the stack is covered with a sealing body, the generated gas has no way to escape. As a result, heat inside the electricity storage module cannot be dissipated, and there is a risk of the electricity storage device being damaged.

[0005] The present disclosure has been made to solve such problems, and provides an electricity storage module that is capable of discharging gas generated when the temperature of the stack rises to the outside. [Means for solving the problem]

[0006] The energy storage module according to the present disclosure comprises a laminate in which a plurality of electrodes are stacked, a resin portion provided on at least a portion of a side surface of the laminate along the stacking direction of the electrodes from the top surface to the bottom surface of the energy storage module, and a sealing body provided so as to surround the side surface of the laminate and the resin portion, and the melting point of the resin portion is lower than the melting point of the sealing body. [Effects of the Invention]

[0007] The present disclosure makes it possible to provide an electricity storage module that can discharge gas generated by an increase in the temperature of the stack to the outside. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view of an electricity storage module according to the present disclosure. [Figure 2] FIG. 2 is a plan view of the power storage module according to the present disclosure. [Figure 3] 3A and 3B are explanatory diagrams of the energy storage module according to the present disclosure when thermal runaway occurs. Fig. 3A shows the state immediately after thermal runaway occurs, Fig. 3B shows the state when the resin portion begins to melt, and Fig. 3C shows the state when the resin portion has flowed out of the energy storage module and a gas exhaust passage has been formed. DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention will be described below through embodiments of the invention, but the invention according to the claims is not limited to the following embodiments. Furthermore, not all of the configurations described in the embodiments are necessarily essential means for solving the problems. For clarity of explanation, the following description and drawings have been omitted and simplified as appropriate. In each drawing, the same elements are given the same reference numerals, and repeated explanations are omitted as necessary.

[0010] Embodiment 1 <Energy storage module> The configuration of the power storage module according to the present disclosure will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a cross-sectional view of the power storage module according to the present disclosure. Fig. 2 is a plan view of the power storage module according to the present disclosure.

[0011] 1, the energy storage module 1 includes one or more laminates 10, a sealing body 20, and a resin part 30. The energy storage module 1 is, for example, a so-called bipolar battery including bipolar electrodes, which will be described later. More specifically, the energy storage module 1 may be, for example, a lithium-ion secondary battery, a nickel-metal hydride secondary battery, or an electric double layer capacitor.

[0012] The laminate 10 has a plurality of electrodes, specifically bipolar electrodes, stacked with separators interposed between them. In the following description, an xyz three-dimensional Cartesian coordinate system is used as appropriate. The x, y, and z directions are parallel to each side of the rectangular parallelepiped laminate 10. The separators and each electrode are stacked along the z direction.

[0013] The bipolar electrode is an electrode comprising an electrode plate, a positive electrode, and a negative electrode. A negative terminal electrode is disposed at a first end of the laminate 10, and a positive terminal electrode is disposed at a second end opposite the first end of the laminate 10. The negative terminal electrode is an electrode comprising an electrode plate and a negative electrode. The positive terminal electrode is an electrode comprising an electrode plate and a positive electrode. Multiple bipolar electrodes are disposed between the negative terminal electrode and the positive terminal electrode in the stacking direction (z direction).

[0014] The sealing body 20 is provided so as to surround the side surface of the laminate 10 and the resin portion 30. The sealing body 20 is, for example, a sealing material or a potting material. More specifically, examples of materials used for the sealing body 20 include polypropylene, polyphenylene sulfide, and modified polyphenylene ether.

[0015] As shown in FIG. 2, the resin part 30 is provided on at least a part of the side surface of the laminate 10. More specifically, as shown in FIG. 1, the resin part 30 is provided so as to extend from the top surface U to the bottom surface L of the energy storage module 1 along the electrode stacking direction (z direction). The top surface U refers to the upper surface of the laminate 10. When the energy storage module 1 includes a plurality of laminates 10, the top surface U refers to the top surface (+z side surface) of the laminate 10 arranged at the top (+z side). The bottom surface L refers to the bottom surface of the laminate 10. When the energy storage module 1 includes a plurality of laminates 10, the bottom surface L refers to the bottom surface (-z side surface) of the laminate 10 arranged at the bottom (-z side).

[0016] The resin part 30 serves as a discharge passage for discharging gas generated from the laminate 10 to the outside of the energy storage module 1. More specifically, the resin part 30 is melted by the gas, forming a discharge passage for discharging the gas to the outside of the energy storage module 1. In other words, the location where the resin part 30 was located becomes the gas discharge passage. The melting point of the resin part 30 is preferably lower than the melting point of the sealing body 20. Furthermore, it is preferable that the material of the resin part 30 be one that can easily peel off from the sealing body 20.

[0017] Next, a method of discharging gas by melting the resin part 30 according to the present disclosure will be described with reference to Fig. 3. Fig. 3 is an explanatory diagram of a power storage module according to the present disclosure when thermal runaway occurs. Fig. 3(a) shows the state immediately after thermal runaway occurs, Fig. 3(b) shows the state when the resin part begins to melt, and Fig. 3(c) shows the state when the resin part has flowed out of the power storage module and a gas discharge path has been formed.

[0018] For example, when the energy storage module 1 experiences thermal runaway, gas G is generated from the laminate 10 as shown in FIG. 3(a). Next, as shown in FIG. 3(b), the resin part 30 melts due to the heat of the gas G. Next, the gas G flows upward (in the +z direction) within the energy storage module 1. At this time, the discharge pressure of the gas G causes the resin part 30 to be pushed upward (in the +z direction) within the energy storage module 1 while melting due to the heat of the gas G. Then, as shown in FIG. 3(c), the resin part 30 flows out of the energy storage module 1, forming a discharge passage 40 for the gas G. This discharge passage 40 allows the gas G to be discharged to the outside without remaining within the energy storage module 1. This makes it possible to prevent damage to the energy storage module due to the gas G.

[0019] As described above, according to the energy storage module 1 of the present disclosure, the resin part 30 is melted by the gas G and then washed out of the energy storage module 1, thereby forming an exhaust passage 40 that can exhaust the gas G to the outside of the energy storage module 1.

[0020] The present invention is not limited to the above-described embodiment, and can be modified as appropriate within the scope of the invention.

[0021] For example, in the above description, the exhaust passage 40 for gas G is filled with the resin part 30, but the energy storage module 1 may also include a hollow exhaust passage 40 that is not filled with the resin part 30. In this case, the hollow exhaust passage 40 is provided on the side surface of the resin part 30. When the energy storage module 1 experiences thermal runaway, the gas G generated from the laminate 10 can flow out into the exhaust passage 40 by melting the resin part 30. The gas G then passes through the exhaust passage 40 and is exhausted to the outside of the energy storage module 1.

[0022] Furthermore, the number of resin parts 30 is not limited to one, and may be multiple. By providing multiple resin parts 30, the energy storage module 1 can form multiple discharge passages 40 for the gas G, and can more efficiently discharge the gas G to the outside of the energy storage module 1. [Explanation of symbols]

[0023] 1. Energy storage module 10 Laminate 20 Sealing body 30 Resin part 40 Discharge passage G Gas L Bottom part U Top section

Claims

[Claim 1] a laminate in which a plurality of electrodes are stacked; a resin portion provided on at least a part of a side surface of the stacked body along a stacking direction of the electrodes from a top surface portion to a bottom surface portion of the energy storage module; a sealing body provided so as to surround the side surface of the laminate and the resin portion, The melting point of the resin portion is lower than the melting point of the sealing body. Energy storage module.

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