Insulation sheet and battery equipped with it

Abstract

To provide an insulating sheet that does not experience an excessive decrease in thermal insulation performance even when subjected to a compressive load in the thickness direction. [Solution] The present invention relates to an insulating sheet 10 that can be interposed between heat sources or between a heat source and a non-heat source to reduce the thermal conductivity in the thickness direction of the sheet, and comprising at least a porous sponge sheet 11 and a layer disposed on the surface of the sponge sheet 11, which is a dispersed layer 21 of a plurality of protrusions 20, and a battery equipped therewith.

Description

Technical Field

[0001] The present invention relates to a heat insulation sheet and a battery including the same.

Background Art

[0002] The power source of automobiles is shifting from engines using fossil fuels such as gasoline and light oil to motors using electricity from batteries. In a lithium-ion battery, which is one type of battery, generally, a plurality of battery cells (also simply referred to as "cells") are arranged in a housing.

[0003] Battery cells may generate heat during charging and discharging. If a battery cell overheats abnormally, the heat is transferred to adjacent battery cells, resulting in overheating of the entire battery and an increased risk of ignition. To prevent such a situation, it is preferable to interpose a material that reduces heat conduction between battery cells between the battery cells. Conventionally, various methods have been studied to make it difficult for the heat of an abnormally high-temperature battery cell to be transferred to surrounding battery cells. For example, a method of providing a heat insulation sheet such as a refractory material or a heat insulation layer between a plurality of battery cells is known (see Patent Document 1).

[0004] On the other hand, when a battery cell overheats, the battery cell container expands. To absorb such expansion, it is preferable to interpose a material with high elastic deformation between the battery cells. To achieve both heat insulation and ease of elastic deformation, methods are known such as using a molded product formed from a porous or fibrous material with low thermal conductivity, or using a sheet comprising a sponge-like molded product and a material whose thermal conductivity is reduced by lowering the thermal conductivity of the material or by minimizing contact points between materials to improve heat insulation effect. Prior to the present invention, the inventors of the present applicant developed a heat insulating sheet comprising a rubber sheet made of a rubber-like elastic body, heat insulating sheets laminated on both sides of the rubber sheet that can reduce heat transfer between multiple adjacent heat sources, and an adhesive layer interposed between the rubber sheet and the heat insulating sheet to bond the heat insulating sheet to both sides of the rubber sheet (see, for example, Patent Document 2). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2018-206604 [Patent Document 2] Japanese Patent Publication No. 2023-062546 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, among the conventional technologies described above, the insulation sheets using porous, easily elastically deformable sponge material still have challenges that need further improvement. The challenge is how to compensate for the decrease in insulation effect caused by the collapse of pores inside the insulation sheet and the reduction of air inside those pores when subjected to a compressive load in the thickness direction of the sheet.

[0007] This invention has been made in view of the above problems, and aims to prevent excessive reduction in the thermal insulation properties of a sheet even when subjected to a compressive load in the thickness direction. [Means for solving the problem]

[0008] (1) An insulating sheet according to one embodiment for achieving the above objective is an insulating sheet that can be interposed between heat sources or between a heat source and a non-heat source to reduce the thermal conductivity in the thickness direction of the sheet, A porous sponge sheet, A layer disposed on the surface of the sponge sheet, comprising a dispersed layer of multiple protrusions, It must have at least the following: (2) In a heat insulating sheet according to another embodiment, preferably, Two or more of the aforementioned sponge sheets are laminated in the thickness direction, The plurality of protrusions are dispersed in a layer between the two sponge sheets and on at least one of the outer surfaces of the sponge sheets in the thickness direction. (3) In another embodiment of the heat insulating sheet, preferably, a heat insulating material with higher heat insulating properties than the sponge sheet is laminated on the sponge sheet. (4) In a thermal insulation sheet according to another embodiment, preferably, the dispersed layer of the plurality of protrusions is sandwiched between the sponge sheet and the thermal insulation material. (5) In another embodiment of the heat insulating sheet, preferably the heat insulating material is arranged on both sides in the thickness direction of the sponge sheet. (6) In a heat insulating sheet according to another embodiment, preferably the sponge sheet is a silicone rubber sheet. (7) In a heat insulating sheet according to another embodiment, the protrusions are preferably granular. (8) In a heat insulating sheet according to another embodiment, preferably the granular material is silicone rubber granular material. (9) In a thermal insulation sheet according to another embodiment, preferably the protrusions are recycled materials from used molded bodies. (10) A battery according to one embodiment for achieving the above objective is a battery comprising one or more battery cells, wherein one of the above-mentioned heat insulating sheets is in contact with the battery cell. [Effects of the Invention]

[0009] According to the present invention, even when subjected to a compressive load in the thickness direction, the thermal insulation properties of the sheet can be prevented from being excessively reduced. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 shows an enlarged view of the main part and a part X of the battery according to the first embodiment of the present invention. [Figure 2] Figure 2 shows a perspective view of a heat insulating sheet according to the first embodiment of the present invention and an enlarged view of a part A of it. [Figure 3] Figure 3 shows a side view of the insulation sheet in Figure 2 and an enlarged view of a part of it, B. [Figure 4] Figure 4 shows the method for manufacturing the insulation sheet shown in Figure 2. [Figure 5] Figure 5 shows an example of a heat source: a state in which the insulating sheet shown in Figure 2 is placed between two battery cells (5A), and a state in which the battery cells have expanded in the thickness direction from that state, as well as a magnified view of part of C (5B). [Figure 6] Figure 6 shows an assembled perspective view of the heat insulating sheet according to the second embodiment of the present invention. [Figure 7] Figure 7 shows a side view of the insulation sheet shown in Figure 6. [Figure 8] Figure 8 shows an example of a heat source, where the insulating sheet shown in Figure 7 is placed between battery cells (8A), and a state in which the battery cells have expanded in the thickness direction from that state, as well as a magnified view of part D (8B). [Figure 9] Figure 9 shows an assembled perspective view of the heat insulating sheet according to the third embodiment of the present invention. [Modes for carrying out the invention]

[0011] Next, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments described below do not limit the invention according to the claims, and not all of the elements and combinations thereof described in the embodiments are essential for the solution of the present invention.

[0012] <First Embodiment> First, a heat insulation sheet according to the first embodiment of the present invention and a battery including the same will be described.

[0013] FIG. 1 shows a main part of a battery according to the first embodiment of the present invention and an enlarged view of a part X thereof.

[0014] The battery 1 according to this embodiment is, for example, a battery for an electric vehicle, and is preferably a lithium-ion battery. The battery 1 has one or more battery cells (also simply referred to as "cells") 5 arranged thereon, and a heat insulation sheet 10 is sandwiched between the battery cells 5. The battery 1 is a battery including one or more battery cells 5, and includes the heat insulation sheet 10 in contact with the battery cells 5. The heat insulation sheet 10 is a sheet for minimizing the spread of fire to adjacent battery cells 5 even when some of the battery cells 5 are in an overheated state and, in the worst case, catch fire. Further, the heat insulation sheet 10 is a sheet that can be elastically deformed in the thickness direction. The plurality of battery cells 5 are compressed in the direction in which they are arranged and set in the battery 1. At this time, the heat insulation sheet 10 undergoes compressive deformation under the compression from the battery cells 5. On the other hand, when the compression of the plurality of battery cells 5 is released, the heat insulation sheet 10 returns to its original thickness. Furthermore, the heat insulation sheet 10 can be elastically deformed in accordance with the deformation of the battery cells 5 accompanying the thermal expansion of the battery cells 5, which are an example of a heat source.

[0015] FIG. 2 shows a perspective view of the heat insulation sheet according to the first embodiment of the present invention and an enlarged view of a part A thereof. FIG. 3 shows a side view of the heat insulation sheet of FIG. 2 and an enlarged view of a part B thereof.

[0016] The heat insulating sheet 10 according to this embodiment is a sheet that can be interposed between heat sources or between a heat source and a non-heat source to reduce the heat conductivity in the thickness direction of the sheet, and comprises at least a porous sponge sheet 11 and a layer disposed on the surface of the sponge sheet 11, which is a dispersed layer 21 of a plurality of protrusions 20. An example of a heat source is a battery cell 5. An example of a non-heat source is the housing of the battery 1.

[0017] (1) Sponge sheet The sponge sheet 11 has many pores 12, which may be independent or communicate with each other. The air present inside the pores 12 contributes to the high heat insulation properties of the sponge sheet 11. The sponge sheet 11 is composed of, for example, thermosetting elastomers such as silicone rubber, urethane rubber, isoprene rubber, ethylene propylene rubber, natural rubber, ethylene propylene diene rubber, nitrile butadiene rubber (NBR), or styrene butadiene rubber (SBR); thermoplastic elastomers such as urethane-based, ester-based, styrene-based, olefin-based, butadiene-based, and fluorine-based elastomers, or composites thereof. A silicone rubber sheet with excellent heat resistance is preferred as the sponge sheet 11. The sponge sheet 11 may also contain fillers such as silica and graphite.

[0018] The sponge sheet 11 may be a single sheet or a laminate of two or more sheets. The sponge sheet 11 may also have a sheet made of a different material interposed between the laminate of two or more sheets. The thickness of the sponge sheet 11 is not particularly limited, but is preferably 0.5 to 20 mm, more preferably 1 to 10 mm, and even more preferably 1.5 to 6 mm.

[0019] (2) Dispersed layer of multiple protrusions The dispersed layer 21 comprises a plurality of protrusions 20. The dispersed layer 21 is provided on the surface of the sponge sheet 11, particularly on at least one side, preferably both sides, in the thickness direction. The protrusions 20 may be located in some of the holes 12 that open to the surface of the sponge sheet 11. The protrusions 20 are provided to ensure voids in the entire heat insulating sheet 10 even if the holes 12 inside the sponge sheet 11 are crushed when the sponge sheet 11 is compressed in the thickness direction. Regions sandwiched between adjacent protrusions 20 contribute to the formation of these voids. The average diameter of the protrusions 20 is preferably 0.1 to 5 mm, more preferably 0.3 to 3 mm, and even more preferably 0.5 to 1 mm. Here, the average diameter is preferably the diameter measured by laser diffraction / scattering.

[0020] The protrusion 20 is preferably made of rubber, resin (excluding rubber), ceramics, glass, metal and / or wood. The protrusion 20 is more preferably made of rubber, and even more preferably of thermosetting elastomers such as silicone rubber, urethane rubber, isoprene rubber, ethylene propylene rubber, natural rubber, ethylene propylene diene rubber, nitrile butadiene rubber (NBR), or styrene butadiene rubber (SBR); thermoplastic elastomers such as urethane-based, ester-based, styrene-based, olefin-based, butadiene-based, fluorine-based, or composites thereof. The protrusion 20 is preferably made of granular material. The granular material is more preferably made of silicone rubber granules. The granular material may also be recycled material from used molded products. An example of recycled material from used molded products is silicone rubber with a Shore A hardness of 70 degrees that has been crushed in a No. 120 rotary grinder.

[0021] Figure 4 shows the method for manufacturing the insulation sheet shown in Figure 2.

[0022] First, a sponge sheet 11 molded into a predetermined shape (preferably a plate shape) is prepared (sponge sheet preparation step, (a)). Next, in a container 25, the protrusions 20 (preferably granular) are dispersed in a liquid 26 containing only volatile components or volatile components. The liquid 26 is 100% volatile components that evaporate at room temperature (20-25°C), such as thinner, acetone, ethyl alcohol, or water, or contains non-volatile components (e.g., resin components) in addition to the volatile components. The mixture 27 of the protrusions 20 and liquid 26 is applied to the surface of the sponge sheet 11 (mixture application step, (b)). As for the liquid 26, for example, a mixture of a one-component room-temperature fast-curing adhesive mainly composed of a silyl group-containing special polymer and thinner can be cited. The application method is not particularly limited, but for example, brush application, a method using a bar coater, spray application, or a method of dipping the sponge sheet 11 into the mixture 27 can be cited. Next, the volatile components are evaporated from the mixture 27 applied to the surface of the sponge sheet 11, leaving the protrusions 20 on the surface of the sponge sheet 11 (volatilization step, (c)). In Figure 4, the mixture 27 is applied to only one side in the thickness direction of the sponge sheet 11, but the mixture 27 may also be applied to both sides in the thickness direction of the sponge sheet, or to the entire outer surface of the sponge sheet 11.

[0023] After the volatilization process, the protrusions 20 protrude from the surface of the sponge sheet 11, regardless of whether their surface is coated or not. Therefore, even if the liquid 26 contains non-volatile components (such as resin), it contains such an amount of non-volatile components that the protrusions 20 are not completely embedded in the layer of non-volatile components.

[0024] Figure 5 shows an example of a heat source: a state in which the insulating sheet shown in Figure 2 is placed between two battery cells (5A), and a state in which the battery cells have expanded in the thickness direction from that state, as well as a magnified view of part of C (5B).

[0025] Before the battery cell 5 expands, air is stored in the pores 12 within the sponge sheet 11. Air is also present in the region surrounded by the protrusions 20, the surface of the sponge sheet 11, and the battery cell 5 (see 5A). When the battery cell 5 expands (black arrow), the insulation sheet 10 is compressed in its thickness direction. As a result, the pores 11 collapse, and the amount of air inside them decreases. This leads to a decrease in the insulation properties of the sponge sheet 11 itself. However, air is still present in the region surrounded by the protrusions 20, the surface of the sponge sheet 11, and the battery cell 5 (see 5B). The protrusions 20 are not completely embedded in the sponge sheet 11 or the battery cell 5. As a result, the air in both of the above regions does not disappear. Therefore, these regions have the function of compensating for the insulation properties that would result from the reduction in the size of the pores 12.

[0026] <Second Embodiment> Next, a heat insulating sheet and a battery equipped therewith according to a second embodiment of the present invention will be described. In the second embodiment, the description of parts common to the first embodiment will be omitted.

[0027] The battery 1 according to the second embodiment is identical to the battery 1 according to the first embodiment, except for the heat insulating sheet sandwiched between the battery cells 5 or between the battery cells 5 and the housing.

[0028] Figure 6 shows an assembled perspective view of the heat insulating sheet according to the second embodiment of the present invention. Figure 7 shows a side view of the heat insulating sheet of Figure 6.

[0029] The heat insulating sheet 10a is a sheet that can reduce thermal conductivity in the thickness direction of the sheet by being interposed between heat sources (e.g., battery cells 5) or between a heat source (battery cell 5) and a non-heat source (e.g., the housing of the battery 1). The sheet has a sponge sheet 11 on which heat insulating materials 31 and 32 that have higher heat insulating properties than the sponge sheet 11 are laminated. The dispersed layer 21 of the multiple protrusions 20 is sandwiched between the sponge sheet 11 and the heat insulating material 31 (and heat insulating material 32). The heat insulating materials 31 and 32 are arranged on both sides of the thickness direction of the sponge sheet 11. The dispersed layer 21 of the multiple protrusions 20 may be provided on the surface of the heat insulating material 31 and 32 facing the sponge sheet 11, as long as it exists between the sponge sheet 11 and the heat insulating materials 31 and 32.

[0030] In the insulation sheet 10a, the insulation materials 31 and 32 are arranged on both sides in the thickness direction of the sponge sheet 11. However, either one of the insulation materials 31 or 32 may be provided on only one side in the thickness direction of the sponge sheet 11.

[0031] Furthermore, similar to the heat insulating sheet 10 according to the first embodiment, in the heat insulating sheet 10a, preferably, the sponge sheet 11 is a sheet of silicone rubber. Furthermore, in the heat insulating sheet 10a, preferably, the protrusions 20 are granular. Furthermore, in the heat insulating sheet 10a, preferably, the granular material is granular silicone rubber. Furthermore, in the heat insulating sheet 10a, preferably, the granular material is a recycled material from a used molded body.

[0032] Since the sponge sheet 1, the dispersed layer 21, and the protrusions 20 are the same as in the first embodiment, redundant explanations will be omitted.

[0033] The thermal insulation materials 31 and 32 are preferably metal oxide-containing sheets and are present on both sides (or one side) of the thickness direction of the sponge sheet 11, enhancing the thermal insulation properties of the thermal insulation sheet 10a. The thermal insulation materials 31 and 32 are preferably in the form of nonwoven fabric sheets, but are not limited to that form. The thermal insulation materials 31 and 32 are preferably sheets mainly containing talc, diatomaceous earth, silica, aerogel (e.g., silica aerogel), mullite, cordierite, steatite, forsterite, titania, or zirconia, and more preferably sheets mainly containing talc, diatomaceous earth, silica, or aerogel. Talc is generally a ceramic mainly composed of hydrated magnesium silicate and contains small amounts of impurities such as iron oxide. The type and amount of impurities vary depending on the origin of the talc ore, but the talc contained in the thermal insulation materials 31 and 32 is not particularly limited in that respect.

[0034] The term "primarily" above means that the ratio of the mass of metal oxides such as talc, diatomaceous earth, silica, aerogel, mullite, cordierite, steatite, forsterite, titania, or zirconia to the total mass of the thermal insulation materials 31 and 32 exceeds 50% by mass. The content of the metal oxides in the total thermal insulation materials 31 and 32 is preferably 51% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more. In addition to the above metal oxides, the thermal insulation materials 31 and 32 may also contain relatively heat-resistant materials such as silicone rubber, aramid fibers, and polyphenylene sulfide. Furthermore, the thermal insulation materials 31 and 32 may be composed almost entirely or entirely of the above metal oxides. There are no particular restrictions on the manufacturing method of the thermal insulation materials 31 and 32, but examples include a manufacturing method that includes a process similar to the papermaking process included in the paper manufacturing process, a method of molding the thermal insulation material by placing it in a mold, and a method of shaping a molten material containing the material into a sheet shape using a 3D printer. The thickness of the insulation materials 31 and 32 is not particularly restricted, but is preferably 0.1 to 15 mm, more preferably 0.5 to 7 mm, and even more preferably 0.8 to 3 mm. The thickness of the insulation materials 31 and 32 is preferably less than the thickness of the sponge sheet 11.

[0035] The method for manufacturing the heat insulating sheet 10a is the same as in the first embodiment up to the point where the protrusions 20 are formed on the sponge sheet 11. In the second embodiment, the heat insulating materials 31 and 32 are then attached to the sponge sheet 11 from the thickness direction (heat insulating material attachment step). There are no particular restrictions on the method of attaching the heat insulating materials 31 and 32, but examples include bonding, welding, and fitting.

[0036] When manufacturing an insulating sheet 10a with a dispersion layer 21 on the insulating material 31, 32 side, only the sponge sheet preparation step shown in Figure 4(a) is common. Instead of the mixture coating step shown in Figure 4(b), a mixture 27 of the protrusions 20 and liquid 26 is applied to at least the surface of the insulating material 31, 32 facing the sponge sheet 11 (mixture coating step). Next, instead of the volatilization step shown in Figure 4(c), a step of volatilizing the volatile components in the mixture 27 applied to the insulating material 31, 32 is performed (volatilization step). After that, the insulating material application step described above is performed.

[0037] Figure 8 shows an example of a heat source: a state in which the insulating sheet shown in Figure 7 is placed between battery cells (8A), and a state in which the battery cells have expanded in the thickness direction from that state, as well as a magnified view of part D (8B).

[0038] Before the battery cell 5 expands, air is stored in the pores 12 within the sponge sheet 11. Air is also present in the region surrounded by the protrusions 20, the surface of the sponge sheet 11, and the insulation materials 31 and 32 (see 8A). When the battery cell 5 expands (black arrow), the insulation sheet 10a is compressed in its thickness direction. As a result, the pores 11 collapse, and the amount of air inside them decreases. This leads to a decrease in the thermal insulation performance of the sponge sheet 11 itself. However, air is still present in the region surrounded by the protrusions 20, the surface of the sponge sheet 11, and the insulation materials 31 and 32 (see 8B). The protrusions 20 are not completely embedded in the sponge sheet 11 or the insulation materials 31 and 32. As a result, the air in both of the above regions does not disappear. Therefore, these regions have the function of compensating for the reduced thermal insulation performance due to the shrinkage of the pores 12.

[0039] <Third Embodiment> Next, a heat insulating sheet and a battery equipped therewith according to the third embodiment of the present invention will be described. In the third embodiment, the description of parts that are common with the first or second embodiment will be omitted.

[0040] The battery 1 according to the third embodiment is the same as the battery 1 according to the first or second embodiment, except for the heat insulating sheet sandwiched between the battery cells 5 or between the battery cells 5 and the housing.

[0041] Figure 9 shows an assembled perspective view of the heat insulating sheet according to the third embodiment of the present invention.

[0042] The heat insulating sheet 10b according to the third embodiment has a structure in which two heat insulating sheets 10 according to the first embodiment are laminated. That is, the heat insulating sheet 10b has two sponge sheets 11 laminated in the thickness direction, and a dispersed layer 21 of multiple protrusions 20 is provided between the sponge sheets 11 and on the outer surface of the sponge sheets 11 in the thickness direction. The layer configuration of the heat insulating sheet 10b in the thickness direction is dispersed layer 21 / sponge sheet 11 / dispersed layer 21 / sponge sheet 11 / dispersed layer 21. However, the layer configuration of the heat insulating sheet 10b may be sponge sheet 11 / dispersed layer 21 / sponge sheet 11, or dispersed layer 21 / sponge sheet 11 / dispersed layer 21 / sponge sheet 11.

[0043] Alternatively, the insulating materials 31 and 32 may be laminated from both sides in the thickness direction of the insulating sheet 10b having any of the aforementioned layer configurations, or the insulating material 31 (or insulating material 32) may be laminated only from one side in the thickness direction of the insulating sheet 10b.

[0044] Similar to the heat insulating sheet 10 according to the first embodiment, in the heat insulating sheet 10b, the sponge sheet 11 is preferably a sheet of silicone rubber. Furthermore, in the heat insulating sheet 10b, the protrusions 20 are preferably granular. Also, in the heat insulating sheet 10b, the granular material is preferably granular silicone rubber. Furthermore, in the heat insulating sheet 10b, the granular material is preferably a recycled material from a used molded body.

[0045] <Common configuration across all mechanisms> In each of the embodiments described above, a dispersed layer 21 of multiple protrusions 20 is formed between the sheets constituting the thermal insulation sheets 10, 10a, and 10b, or on the exposed outer surface of the sheets. Adhesive may be used for lamination between the sheets. However, the thickness of the adhesive layer is such that the protrusions 20 are not completely embedded. As a result, air remains in the voids formed between the multiple protrusions 20. These voids are not as easily compressed as the holes 12 inside the sponge sheet 11. Therefore, when the thermal insulation sheets 10, 10a, and 10b are compressed in the thickness direction, the holes 12 shrink, reducing the amount of air. This reduces the thermal insulation performance of the thermal insulation sheets 10, 10a, and 10b, but the air in the voids within the dispersed layer 21 compensates for this reduction in thermal insulation performance. As a result, the thermal insulation sheets 10, 10a, and 10b as a whole do not significantly reduce their thermal insulation performance before and after compression.

[0046] <Other Embodiments> Although preferred embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above and can be modified in various ways.

[0047] For example, an insulating material equivalent to the insulating materials 31 and 32 may be provided inside the sponge sheet 11 together with the insulating materials 31 and 32, or in place of the insulating materials 31 and 32. The battery 1 may be equipped with a combination of multiple insulating sheets 10, 10a, and 10b. In the insulating sheet 10a according to the second embodiment, instead of sandwiching one sponge sheet 11 between insulating materials 31 and 32, two or more sponge sheets 11 may be sandwiched between insulating materials 31 and 32. Also, the sponge sheets 11 constituting the insulating sheet 10b according to the third embodiment are not limited to two, but may be three or more.

[0048] The various heat insulating sheets 10, 10a, and 10b described above may be used not only for installation on the battery 1, but also for placement between circuit boards, between electronic components, or between circuit boards and electronic components in electronic devices.

[0049] The components or processes of each of the above embodiments can be combined in any way, except where they are incompatible. In particular, each claim can be combined in any way. [Industrial applicability]

[0050] This invention can be used in parts that require heat insulation from a heat source. [Explanation of Symbols]

[0051] 1...Battery, 5...Battery cell (example of heat source), 10, 10a, 10b...Insulation sheet, 11...Sponge sheet, 12...Perforations, 20...Protrusions (e.g., granular material), 21...Dispersed layer, 31, 32...Insulation material.

Claims

1. An insulating sheet that can reduce thermal conductivity in the thickness direction of the sheet when interposed between heat sources or between a heat source and a non-heat source, A porous sponge sheet, A layer disposed on the surface of the sponge sheet, comprising a dispersed layer of multiple protrusions, An insulating sheet characterized by comprising at least the following.

2. Two or more of the aforementioned sponge sheets are laminated in the thickness direction, The thermal insulation sheet according to claim 1, characterized in that it comprises a dispersed layer of the plurality of protrusions between two of the sponge sheets and on at least one of the outer surfaces of the sponge sheets in the thickness direction.

3. The thermal insulation sheet according to claim 1, characterized in that a thermal insulation material with higher thermal insulation properties than the sponge sheet is laminated onto the sponge sheet.

4. The thermal insulation sheet according to claim 3, characterized in that the dispersed layer of the plurality of protrusions is sandwiched between the sponge sheet and the thermal insulation material.

5. The insulating sheet according to claim 3, characterized in that the insulating material is arranged on both sides in the thickness direction of the sponge sheet.

6. The heat insulating sheet according to claim 1, characterized in that the sponge sheet is a sheet of silicone rubber.

7. The heat insulating sheet according to claim 1, characterized in that the aforementioned protrusions are granular.

8. The heat insulating sheet according to claim 7, characterized in that the granular material is granular silicone rubber.

9. The thermal insulation sheet according to claim 1, characterized in that the aforementioned protrusions are recycled materials from used molded bodies.

10. A battery comprising one or more battery cells, characterized in that it comprises a heat insulating sheet according to any one of claims 1 to 9 in contact with the battery cells.

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