Battery buffer material

Abstract

To provide a battery buffer material that has thermal insulation performance by being provided with a thermal insulation member, and that is resistant to deterioration in thermal insulation performance even when compressed by an external force in the thickness direction.SOLUTION: A battery buffer material 100 includes an elastic member 20 having a protrusion 22, and an insulating member 30 which is a plate-like structure having a through hole 31 formed therein, the insulating members 30 are disposed on one side and the other side of the elastic member 20, and the protrusion 22 of the elastic member 20 protrudes from the through hole 31 of the insulating member 30.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a cushioning material for batteries, and more particularly to a cushioning material for batteries such as secondary batteries used in electric vehicles and the like. [Background technology]

[0002] Conventionally, batteries (secondary batteries) have been widely used as energy sources for electric vehicles and the like. These batteries include a plurality of battery cells and cushioning materials (battery cushioning materials), etc. Known configurations of these battery cells include an electrode assembly in which a positive electrode, a negative electrode, and a separator are laminated, and the electrode assembly is housed in a storage case.

[0003] This battery is a lithium ion battery, etc. The battery is provided with a restraining portion that restrains a plurality of storage cases (battery cells) containing electrode assemblies that constitute the battery in a stacked manner in a stacking direction. The restraining portion is disposed on the outside of the storage case and restrains the storage case from the outside.

[0004] In such a battery, a plurality of storage cases (battery cells) are arranged in a state where they are restrained by the restraining portion, and expand and contract due to heat generated during charging and discharging.

[0005] In batteries, the electrodes (electrode particles) may break due to volume changes caused by expansion and contraction accompanying the above-mentioned charging and discharging, and in such cases, the battery's lifespan tends to be shortened. In addition, if a specific battery cell inside the battery generates heat, this heat can trigger other battery cells to heat up, causing the battery temperature to continue to rise, and there is a concern that the battery may go into thermal runaway or catch fire.

[0006] For these reasons, it is important for a battery to suppress expansion and contraction of battery cells during use and to insulate the battery cells from thermal runaway. Therefore, a cushioning material (battery cushioning material) that includes a heat-resistant elastic body and a heat insulating material to ensure thermal insulation is placed between adjacent battery cells (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2021-140968 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, in the case of a laminated structure (cushion material) in which a heat insulating section and a buffer section are stacked as shown in Fig. 1A of the battery insulating material in Patent Document 1, the heat insulating section is also subjected to an external force in its thickness direction and compressed due to the expansion of the battery cell. When compressed by an external force in this way, there is a concern that the heat insulating performance of the heat insulating section will decrease.

[0009] In particular, since the intervals between the cells that make up the battery (i.e., the arrangement space of the cushioning material for the battery) are very narrow and when one cell generates heat, the heat is easily transferred to the adjacent cell, it is desirable to suppress even a slight decrease in the insulation performance. Therefore, there has been a demand for the development of a cushioning material for batteries that has insulation performance and is less likely to decrease in insulation performance even when compressed by an external force in the thickness direction.

[0010] The present invention has been made in consideration of such conventional technology, and its object is to develop a cushioning material for batteries that has insulating performance due to being equipped with an insulating member, and whose insulating performance is less likely to deteriorate even when compressed by an external force in the thickness direction. [Means for solving the problem]

[0011] According to the present invention, there is provided a cushioning material for a battery as described below.

[0012] [1] An elastic member having a protrusion; A heat insulating member which is a plate-like structure having a through hole formed therein, A cushioning material for a battery, wherein the insulating member is arranged on one side and the other side of the elastic member, and the convex portion of the elastic member protrudes from the through hole of the insulating member.

[0013] [2] At least one of the articles is placed between two articles that expand and contract; An elastic member that is compressively deformed by receiving an external force due to the expansion and contraction of the article; The cushioning material for a battery comprises: an insulating member that does not undergo compressive deformation even when the elastic member is compressed and deformed without receiving an external force from the article.

[0014] [3] The cushioning material for a battery described in [2], wherein the elastic member and the insulating member are separate bodies. Effect of the Invention

[0015] The cushioning material for batteries of the present invention has insulating properties due to the insulated member, and has the effect of preventing the insulating properties from deteriorating even when compressed by an external force in the thickness direction. [Brief description of the drawings]

[0016] [Figure 1] 1 is a perspective view showing a schematic diagram of one embodiment of a cushioning material for a battery of the present invention. FIG. [Diagram 2] 1 is a plan view showing a schematic diagram of one embodiment of a cushioning material for a battery of the present invention. FIG. [Diagram 3] 3 is a cross-sectional view that illustrates the AA cross section of the cushioning material for a battery illustrated in FIG. 2. [Figure 4A] FIG. 2 is a perspective view showing a schematic diagram of one embodiment of a protrusion in the cushioning material for a battery of the present invention. [Figure 4B] FIG. 11 is a perspective view showing a schematic view of a convex portion in another embodiment of the cushioning material for a battery of the present invention. [Figure 4C] FIG. 11 is a perspective view showing a schematic view of a convex portion in a cushioning material for a battery according to still another embodiment of the present invention. [Figure 4D] FIG. 11 is a perspective view showing a schematic view of a convex portion in a cushioning material for a battery according to still another embodiment of the present invention. [Figure 4E] FIG. 11 is a perspective view showing a schematic view of a convex portion in a cushioning material for a battery according to still another embodiment of the present invention. [Figure 4F] FIG. 11 is a perspective view showing a schematic view of a convex portion in a cushioning material for a battery according to still another embodiment of the present invention. [Figure 4G] FIG. 11 is a perspective view showing a schematic view of a convex portion in a cushioning material for a battery according to still another embodiment of the present invention. [Diagram 5] FIG. 4 is a plan view illustrating a battery cushioning material according to another embodiment of the present invention. [Figure 6] FIG. 11 is a plan view illustrating a battery cushioning material according to still another embodiment of the present invention. [Figure 7] 7 is a cross-sectional view that shows a schematic cross section of the battery cushioning material shown in FIG. 6 taken along the line BB. [Figure 8] 8 is an explanatory diagram illustrating a schematic state of the battery cushioning material illustrated in FIG. 7 during compression deformation. FIG. [Figure 9] FIG. 11 is a plan view illustrating a battery cushioning material according to still another embodiment of the present invention. [Figure 10] 10 is a cross-sectional view that illustrates a CC cross section of the cushioning material for a battery illustrated in FIG. 9. [Figure 11] FIG. 2 is a perspective view showing a schematic diagram of still another embodiment of the cushioning material for a battery of the present invention. [Figure 12] 12 is a cross-sectional view that illustrates a cross section in a thickness direction of the cushioning material for a battery illustrated in FIG. 11. [Figure 13] 13 is a cross-sectional view corresponding to FIG. 12 in yet another embodiment of the cushioning material for a battery of the present invention. FIG. [Figure 14]FIG. 11 is a plan view illustrating a battery cushioning material according to still another embodiment of the present invention. [Figure 15] 15 is a cross-sectional view that typically shows a DD cross section of the cushioning material for a battery shown in FIG. 14. [Figure 16] 16 is an explanatory diagram illustrating a schematic state of the battery cushioning material illustrated in FIG. 15 during compression deformation. FIG. [Figure 17] FIG. 1 is a cross-sectional view showing a schematic state of use of one embodiment of a cushioning material for a battery of the present invention. [Figure 18] FIG. 2 is a cross-sectional view showing a schematic diagram of another state of use of the embodiment of the cushioning material for a battery of the present invention. [Figure 19] FIG. 1 is a perspective view showing a typical example of a conventional cushioning material for a battery. [Figure 20] FIG. 1 is an explanatory diagram showing a schematic diagram of a conventional battery cushioning material subjected to external pressure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. It should be understood that the present invention is not limited to the following embodiment, and that appropriate design changes, improvements, etc. may be made based on the ordinary knowledge of a person skilled in the art without departing from the spirit of the present invention.

[0018] (1) Battery cushioning: The cushioning material for batteries of the present invention is disposed between two articles, at least one of which expands and contracts, and comprises an elastic member which undergoes compressive deformation in response to an external force due to the expansion of the expanding and contracting article, and an insulating member which does not undergo compressive deformation in response to the external force from the articles even when the elastic member undergoes compressive deformation.

[0019] Such a cushioning material for batteries has thermal insulation performance due to the insulative member, and the thermal insulation performance is unlikely to deteriorate even when compressed by an external force in the thickness direction.

[0020] FIG. 19 shows a conventional battery cushioning material 110. The conventional battery cushioning material 110 has a structure in which an elastic member 120 and a heat insulating member 130 are laminated, and when, for example, a battery cell 210 (see FIG. 17) expands, it is compressed in the thickness direction as shown in FIG. 20. There is a concern that the heat insulating performance of the heat insulating member 130 of the battery cushioning material 110 will decrease if the heat insulating member 130 is compressed. In particular, the space between the battery cells that constitute the battery (i.e., the arrangement space of the battery cushioning material) is very narrow, and when one battery cell generates heat, the heat is easily transferred to the adjacent battery cell. For this reason, it is important to suppress even a slight decrease in heat insulating performance of the battery (battery cell).

[0021] 1 to 3 show a battery cushioning material 100 which is one embodiment of the battery cushioning material of the present invention. The battery cushioning material 100 is disposed between two articles such as battery cells 210, 210 (see FIG. 17) of which at least one article expands and contracts, and includes an elastic member 20 which is compressed and deformed by receiving an external force due to the expansion of the expanding and contracting article, and a heat insulating member 30 which is not compressed and deformed by not receiving an external force from the battery cells 210, 210 even when the elastic member 20 is compressed and deformed. The battery cushioning material 100 is an elastic member 20 having a protrusion 22 (plate-shaped structure). Furthermore, the heat insulating member 30 is a plate-shaped structure in which a through hole 31 is formed, and the heat insulating member 30 is disposed on one surface 20a side and the other surface 20b side of the elastic member 20, respectively, and the protrusion 22 of the elastic member 20 protrudes from the through hole 31 of the heat insulating member 30.

[0022] The material of the elastic member 20 is not particularly limited, but examples thereof include rubber, foam, and resin-based elastomer.

[0023] The elastic member 20 has the protrusions 22, which reduces the contact area between the battery cushioning material and an article such as a battery cell, thereby reducing the amount of heat transferred from the contact surface with the article. Furthermore, by supporting the compressive load caused by the expansion of the article with the protrusions 22, the heat insulating member can be prevented from being directly subjected to the load, and as a result, the heat insulating member can be effectively prevented from being compressed.

[0024] The shape of the protrusion 22 is not particularly limited, and may be columnar (specifically, cylindrical) like the protrusion 22 of the elastic member 20 of the battery cushioning material 100 shown in Fig. 1, or may be, for example, a cylinder, a center axis, a sphere, a hexagonal prism, a square prism, a triangular prism, a cone, etc. Fig. 4A shows a cylindrical protrusion 22a, Fig. 4B shows a center axis protrusion 22b, Fig. 4C shows a spherical protrusion 22c, Fig. 4D shows a hexagonal prism protrusion 22d, Fig. 4E shows a square prism protrusion 22e, Fig. 4F shows a triangular prism protrusion 22f, and Fig. 4G shows a cone protrusion 22g.

[0025] 15, the conical protrusion 22g may be a protrusion tapered toward the apex 24. In this way, an air layer is formed between the elastic member 20 and an article such as a battery cell, and this air layer further improves the heat insulating effect.

[0026] There are no particular limitations on the number and arrangement of the protrusions 22 of the elastic member 20, and for example, the same number of protrusions 22 (four in FIG. 2) may be arranged in multiple parallel rows (three rows in FIG. 2) as shown in Fig. 2, or they may be arranged as in the cushioning material for a battery 101 shown in Fig. 5. In the cushioning material for a battery 101 shown in Fig. 5, the protrusions 22 are further arranged between adjacent rows, shifted from one another.

[0027] The elastic member 20 is not particularly limited in terms of its shape, but may have, for example, a planar portion 21 and a protruding portion 22 protruding from the planar portion 21, as shown in Fig. 3. Alternatively, the elastic member 20 may have a plate-like portion 25 in which an elastic body through-hole 23 is formed, as in the case of a cushioning material 103 for a battery shown in Figs. 9 and 10. Furthermore, the elastic member 20 may have a plate-like portion 29 in which an elastic body recess 27 is formed, as in the case of a cushioning material 104 for a battery shown in Figs. 11 to 13.

[0028] Furthermore, the elastic member 20 may be formed in a wave shape (corrugated plate shape) with repeated concaves and convexes in the cross section in the thickness direction, like a battery cushioning material 106 shown in Figs.

[0029] Next, as described above, even when the elastic member 20 is compressed and deformed, the heat insulating member 30 is not subjected to external forces from the articles such as the battery cells 210, 210 (see FIG. 17) and is not compressed and deformed.

[0030] The heat insulating member 30 can be made of any known heat insulating material having heat insulating properties, and examples of the material include fibrous materials (glass wool, rock wool, etc.), porous materials (silica aerogel, etc.), etc. Heat insulating members made of such materials tend to lose their heat insulating properties when compressed.

[0031] The shape of the heat insulating member 30 is not particularly limited, but it may be a plate-like member with a through hole 31 formed therein, as in the cushioning materials 100 and 106 for a battery shown in Figs. 1 to 3, 14, and 15. It may also be a plate-like member disposed in the elastic body through hole 23, as in the cushioning materials 103 for a battery shown in Fig. 9. It may also be a plate-like member disposed in the elastic body recess 27 of the plate-like portion 29, as in the cushioning materials 104 and 105 for a battery shown in Figs. 12 and 13.

[0032] Next, it is preferable that the battery cushioning material of the present invention has a gap between the elastic member (particularly, the convex portion of the elastic member) and the heat insulating member that allows the elastic member to be compressed and deformed, that is, a gap that prevents the elastic member (particularly, the convex portion of the elastic member) and the heat insulating member from contacting and interfering with each other when the elastic member is compressed and deformed. By forming such a gap, it is possible to further prevent the load applied to the heat insulating member 30 when the battery cell or the like expands.

[0033] 6 to 8 show a cushioning material 102 for a battery in which a gap 40 is formed between the elastic member 20 and the heat insulating member 30, which allows the elastic member 20 to be compressed and deformed. In this cushioning material 102 for a battery, the gap 40 is formed between the heat insulating member 30 and the convex portion 22 of the elastic member 20, and when the cushioning material 100 for a battery is compressed as shown in FIG. 8, the convex portion 22 of the elastic member 20 is deformed so as to be crushed in particular. At this time, since the gap 40 is formed, the heat insulating member 30 can be prevented from being pressed by the elastic member 20 (particularly the convex portion 22) even when the cushioning material 100 for a battery is compressed. In other words, a gap is provided between the heat insulating member 30 and the elastic member 20 by the deformation amount of the elastic member 20 (the convex portion 22), and the elastic member 20 is less likely to interfere with the heat insulating member 30 even when the elastic member 20 is deformed.

[0034] 13 shows a cushioning material 105 for a battery in which a gap 40 is formed between the elastic member 20 and the heat insulating member 30, which allows the elastic member 20 to be compressed and deformed. In this cushioning material 105 for a battery, a gap 40 is formed between the heat insulating member 30 and the protrusion 22 of the elastic member 20. Because this gap 40 is formed, it is possible to prevent the heat insulating member 30 from being pressed by the elastic member 20 even when the cushioning material 105 for a battery is compressed.

[0035] 14 to 16 show a battery cushioning material 106 in which a gap 40 is formed between the elastic member 20 and the heat insulating member 30 to enable the elastic member 20 to be compressed and deformed. In this battery cushioning material 106, the gap 40 is formed between the heat insulating member 30 and the protruding portion 22g of the elastic member 20, and when the battery cushioning material 106 is compressed as shown in FIG. 16, the protruding portion 22g of the elastic member 20 is deformed to be crushed in particular. At this time, since the gap 40 is formed, the heat insulating member 30 can be prevented from being pressed by the elastic member 20 (particularly the protruding portion 22g) even when the battery cushioning material 106 is compressed. In other words, a gap is provided between the heat insulating member 30 and the elastic member 20 by the amount of deformation of the elastic member 20 (protruding portion 22g), and the elastic member 20 is less likely to interfere with the heat insulating member 30 even when the elastic member 20 is deformed.

[0036] As yet another embodiment of the battery cushioning material of the present invention, a battery cushioning material 106 shown in Figs. 14 and 15 can be shown. In this battery cushioning material 106, the elastic member 20 has a protruding portion 22g. Furthermore, the heat insulating member 30 is a plate-like structure in which a through hole 31 is formed, and the heat insulating member 30 is disposed on one surface 20a side and the other surface 20b side of the elastic member 20, respectively, and the protruding portion 22g of the elastic member 20 protrudes from the through hole 31 of the heat insulating member 30. The elastic member 20 has a corrugated shape with repeated protrusions and recesses in a cross section in the thickness direction.

[0037] In the battery cushioning material of the present invention, the elastic member and the heat insulating member are preferably separate bodies. If the elastic member and the heat insulating member are separate bodies, the elastic member 20 is less likely to interfere with the heat insulating member 30 even when the elastic member 20 is deformed.

[0038] (2) Use of the battery cushioning material of the present invention: The battery cushioning material of the present invention is disposed between two articles, at least one of which expands and contracts, and an example of this article can be a battery cell 210 as shown in Fig. 17, and it can be disposed between adjacent battery cells 210 as in the battery 200 shown in Fig. 17. It can also be disposed between a stack of multiple battery cells 210 and a restraining portion 230 as in the battery 201 shown in Fig. 18.

[0039] The battery cushioning material of the present invention can be used not only in one form but also in multiple forms. In this case, multiple battery cushioning materials may be stacked and used, or multiple battery cushioning materials may be arranged on a plane, or these may be combined. The battery is not limited to an all-solid-state battery, and may be a liquid electrolyte battery.

[0040] By being arranged in this manner, the battery cushioning material of the present invention can absorb the expansion force generated when the battery cell (battery) expands, and also function as a cushioning material when the battery is subjected to an impact from an external force. [Industrial Applicability]

[0041] The cushioning material for batteries of the present invention can be used as a cushioning material for batteries such as lithium batteries used in electric vehicles and the like. [Explanation of symbols]

[0042] 20: Elastic member 20a: One side 20b: The other side 21: Planar part 22, 22a, 22b, 22c, 22d, 22e, 22f, 22g: protruding parts 23: Elastic through hole 24: Vertex 25: Plate-shaped part 27: Elastic recess 29: Plate-shaped part 30: Thermal insulation material 31:Through hole 40: Gap 100, 101, 102, 103, 104, 105, 106, 110: Battery cushioning material 200, 201: Battery 210: Battery cell 230: Restraint part

Claims

1. An elastic member having a protrusion; A heat insulating member which is a plate-like structure having a through hole formed therein, A cushioning material for a battery, wherein the insulating member is arranged on one side and the other side of the elastic member, and the convex portion of the elastic member protrudes from the through hole of the insulating member.

2. At least one article is disposed between two articles that expand and contract; An elastic member that is compressively deformed by receiving an external force due to the expansion and contraction of the article; The cushioning material for a battery comprises: an insulating member that does not undergo compressive deformation even when the elastic member is compressed and deformed without receiving an external force from the article.

3. The cushioning material for a battery according to claim 2 , wherein the elastic member and the heat insulating member are separate bodies.

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