Fire spread preventing sheet and battery including the same

Abstract

To provide a fire spread preventing sheet which has excellent heat insulation property, and is elastically deformable corresponding to variation of a pressure applied to a sheet thickness direction, and a battery including the same.SOLUTION: There are provided a fire spread preventing sheet 1, which is arranged at least between a plurality of heat sources, suppresses heat transfer to other heat source when the heat sources are overheated and can prevent fire spread, is formed by laminating a porous first rubber sheet 2 and a solid second rubber sheet 3, wherein the second rubber sheet 3 has one or more storage parts capable of storing air, and a flow channel (groove 5) passing air toward the end of the second rubber sheet 3 from the storage part, and the storage part is a through hole 4 penetrating in a thickness direction of the second rubber sheet 3 or a recess recessed in the thickness direction; and a battery including the same.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a fire prevention sheet and a battery equipped with the same. [Background technology]

[0002] Currently, there is a growing movement around the world to gradually replace conventional gasoline or diesel vehicles with electric vehicles in order to reduce the burden on the global environment. Electric vehicles are becoming increasingly popular, particularly in European countries such as France, the Netherlands, and Germany, as well as in China. The widespread use of electric vehicles requires high-performance batteries.

[0003] Some batteries may experience thermal runaway during discharge or charging, resulting in fire, smoke, or other problems. Recently, automotive batteries with multiple battery cells arranged in a housing have become known. In such a battery with multiple battery cells arranged in a row, if one battery cell were to catch fire or emit smoke, the heat could be transferred to the surrounding battery cells, potentially causing further fires, smoke, explosions, or other problems. To minimize damage caused by such problems, methods have been developed to prevent the transfer of heat from abnormally hot battery cells to the surrounding battery cells. For example, a known method involves providing a fire-prevention sheet, such as a fire-resistant material or a heat-insulating layer, between multiple battery cells (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-206604 Summary of the Invention [Problem to be solved by the invention]

[0005] The containers of battery cells (also simply referred to as "cells") that make up a battery expand when overheated during discharge and / or charging. For this reason, even if a high-hardness ceramic sheet has excellent fire resistance, it is not suitable for preventing fire spread between cells. Generally, when a resin cushion is compressed, the compressive stress depends on the hardness of the cushion. The conventionally known fire spread prevention member disclosed in Patent Document 1 is a single-layer fire-resistant material formed from a urethane resin composition. Therefore, the compressive stress depends on the hardness of the fire-resistant material. Therefore, while the fire spread prevention member can withstand use when the pressure between cells is constant, it is not suitable for use when the pressure between cells fluctuates. For example, if a sheet with low hardness and easy crushing properties is used, it will be too thin under high pressure and will not be able to ensure sufficient thickness. On the other hand, if a sheet with high hardness and resistance to crushing is used, it will hardly be crushed under low pressure, making it difficult to tightly connect the cells. There is a market demand for sheets with high thermal insulation properties that can elastically deform to adapt to changes in pressure in the thickness direction. Meeting these needs will also contribute to achieving the Applicant's Sustainable Development Goal of "ensuring access to affordable, reliable, sustainable and modern energy for all".

[0006] The present invention has been made to solve the above-mentioned problems, and aims to provide a fire spread prevention sheet that has excellent insulating properties and can elastically deform in response to changes in pressure applied in the thickness direction of the sheet, and a battery equipped with the same. [Means for solving the problem]

[0007] (1) In order to achieve the above object, one embodiment of a fire spread prevention sheet is a fire spread prevention sheet that is disposed at least between a plurality of heat sources and that can prevent the spread of fire by suppressing heat transfer to other heat sources when the heat sources are in an overheated state, a porous first rubber sheet; A second solid rubber sheet; and the second rubber sheet includes one or more storage sections capable of storing air, and a flow path for passing air from the storage sections toward an end of the second rubber sheet, The storage portion is a through-hole that penetrates the second rubber sheet in the thickness direction or a recess that is recessed in the thickness direction. (2) The fire spread prevention sheet according to another embodiment preferably has A plurality of the storage sections are provided, The flow path may be formed by connecting the plurality of storage portions and extending to an end of the second rubber sheet. (3) The fire spread prevention sheet according to another embodiment preferably has The second rubber sheet may be sandwiched between two of the first rubber sheets. (4) In another embodiment of the fire spread prevention sheet, preferably, The flow path may be a groove formed on at least one surface of the second rubber sheet in the thickness direction. (5) In another embodiment of the fire spread prevention sheet, preferably, The groove may be formed on a surface facing the first rubber sheet. (6) In another embodiment of the fire spread prevention sheet, preferably, The first rubber sheet and the second rubber sheet may be made of silicone rubber. (7) To achieve the above object, a battery according to one embodiment includes a plurality of battery cells in a housing, Any one of the fire spread prevention sheets described above is provided at least between the battery cells, among between the battery cells and between the battery cells and the housing. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a fire spread prevention sheet that has excellent heat insulation properties and can elastically deform in response to fluctuations in pressure applied in the thickness direction of the sheet, and a battery equipped with the same. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 shows a perspective view of a fire spread prevention sheet according to a first embodiment and an enlarged view of a part X of a side surface thereof. [Figure 2] FIG. 2 shows a perspective view of a fire spread prevention sheet according to a second embodiment and an enlarged view of a part Y of the side surface thereof. [Figure 3] FIG. 3 shows a perspective view of a fire spread prevention sheet according to a third embodiment. [Figure 4] FIG. 4 shows a perspective view of a fire spread prevention sheet according to a fourth embodiment. [Figure 5] FIG. 5 shows a longitudinal cross-sectional view of the battery according to the first embodiment and an enlarged view of one fire spread prevention sheet sandwiched between battery cells in the longitudinal cross-sectional view. [Figure 6] FIG. 6 shows a longitudinal cross-sectional view of a battery according to a second embodiment and an enlarged view of one fire spread prevention sheet sandwiched between battery cells in the longitudinal cross-sectional view. [Figure 7] FIG. 7 shows a longitudinal cross-sectional view of a battery according to a third embodiment and an enlarged view of one fire spread prevention sheet sandwiched between battery cells in the longitudinal cross-sectional view. DETAILED DESCRIPTION OF THE INVENTION

[0010] Next, various embodiments of the present invention will be described with reference to the drawings. Note that the various embodiments described below do not limit the scope of the invention as claimed, and not all of the elements and combinations thereof described in the various embodiments are necessarily essential to the solution of the present invention.

[0011] 1. Fire prevention sheet First Embodiment FIG. 1 shows a perspective view of a fire spread prevention sheet according to a first embodiment and an enlarged view of a part X of a side surface thereof.

[0012] The fire spread prevention sheet 1 according to this embodiment is a sheet that is placed at least between multiple heat sources and can prevent the spread of fire by suppressing heat transfer to other heat sources when a heat source is overheated. Here, examples of "heat sources" include battery cells placed inside an automobile battery, batteries used for devices other than automobiles, or battery cells placed inside such batteries. However, "heat sources" also include, in addition to batteries or battery cells, heaters or their components, and components in electrical or electronic devices (circuit boards, circuit components, etc.).

[0013] The fire spread prevention sheet 1 is made by laminating a first rubber sheet 2 and a second rubber sheet 3. The first rubber sheet 2 is a porous sheet. The second rubber sheet 3 is a solid sheet. Here, "solid" means a form with fewer pores than "porous." A solid sheet is not limited to a sheet with no pores at all, and is broadly interpreted to include sheets with a small number of pores, but means a sheet with an extremely small number of pores compared to a porous (also called foamed) sheet. The first rubber sheet 2 may be called a sponge sheet. The second rubber sheet 3 may be called a solid sheet or a non-sponge sheet.

[0014] The ratio of the thickness of the first rubber sheet 2 to the thickness of the second rubber sheet 3 is preferably first rubber sheet 2:second rubber sheet 3=85:15 to 15:85, and more preferably first rubber sheet 2:second rubber sheet 3=75:25 to 25:75. The thickness of the first rubber sheet 2 is even more preferably the same as or greater than the thickness of the second rubber sheet. A more preferred ratio of the thickness of the first rubber sheet 2 to the thickness of the second rubber sheet 3 is, for example, in the range of 70:30 to 50:50.

[0015] The total thickness of the fire spread prevention sheet 1 is not particularly limited, but is preferably 1 to 20 mm, and more preferably 2 to 8 mm. The thicknesses of the first rubber sheet 2 and the second rubber sheet 3 can be set within the following ranges, for example. The thickness of the first rubber sheet 2 can be set within the range of 0.5 to 15 mm, and the thickness of the second rubber sheet 3 can be set within the range of 0.5 to 15 mm. Alternatively, the thickness of the first rubber sheet 2 can be set within the range of 1 to 6 mm, and the thickness of the second rubber sheet 3 can be set within the range of 1 to 6 mm. The thickness of the first rubber sheet 2 and the thickness of the second rubber sheet 3 may be the same or different.

[0016] The ratio of the volume of holes (also referred to as "voids") 2a in the first rubber sheet 2 to the volume of the first rubber sheet 2 is preferably 30 / 100 to 97 / 100, and more preferably 40 / 100 to 90 / 100. The holes 2a contribute to the function of increasing the heat insulating property of the first rubber sheet 2, and also contribute to the function of facilitating elastic deformation of the first rubber sheet 2 when compressed and released. The second rubber sheet 3 basically does not have holes 2a. However, the second rubber sheet 3 may have a small number of holes 2a. In this case, the ratio of the volume of holes 2a in the second rubber sheet 3 to the volume of the second rubber sheet 2 is preferably 0.001 / 100 to 1 / 100, and more preferably 0.001 / 0.1 to 1 / 100.

[0017] The rubber constituting the first rubber sheet 2 and the second rubber sheet 3 preferably includes a thermosetting elastomer such as silicone rubber, urethane rubber, isoprene rubber, ethylene propylene rubber, natural rubber, ethylene propylene diene rubber, nitrile rubber (NBR), or styrene butadiene rubber (SBR); a thermoplastic elastomer such as a urethane-based, ester-based, styrene-based, olefin-based, butadiene-based, or fluorine-based elastomer, or a composite thereof. Among rubbers, silicone rubber, which has relatively high heat resistance, is more preferably used. Therefore, the first rubber sheet 2 and the second rubber sheet 3 are preferably both silicone rubber sheets.

[0018] The first rubber sheet 2 and the second rubber sheet 3 also differ in hardness. The hardness of the first rubber sheet 2 is lower than that of the second rubber sheet 3. The hardness of each of the first rubber sheet 2 and the second rubber sheet 3 refers to the hardness based on JIS K 6253 and JIS K 7312. The width of each of the first rubber sheet 2 and the second rubber sheet 3 is not particularly limited, but is preferably 50 to 300 mm, more preferably 80 to 150 mm. The length of each of the first rubber sheet 2 and the second rubber sheet 3 is also not particularly limited, but is longer than the width, preferably 200 to 700 mm, more preferably 300 to 600 mm. The size of the first rubber sheet 2 and the second rubber sheet 3 in a plan view may be the same or different.

[0019] The second rubber sheet 3 has one or more storage sections 4 capable of storing air, and grooves 5, which are an example of flow paths for passing air from the storage sections 4 toward the ends of the second rubber sheet 3. In this embodiment, the storage sections 4 are through holes 4a that penetrate the second rubber sheet 3 in the thickness direction. The second rubber sheet 3 preferably has a plurality of through holes 4a, which are an example of storage sections 4. The grooves 5, which are an example of flow paths, are preferably formed by connecting the plurality of through holes 4a and extending to the ends of the second rubber sheet 3.

[0020] The grooves 5 are preferably formed on at least one surface in the thickness direction of the second rubber sheet 3, and more preferably formed on both surfaces in the thickness direction of the second rubber sheet 3. When the grooves 5 are provided on only one surface, the grooves 5 are preferably formed on the surface facing the first rubber sheet 2 (i.e., the surface attached to the first rubber sheet 2).

[0021] The storage section 4 is an area for storing air when the second rubber sheet 3 is sandwiched between the first rubber sheet 2 and the heat source. By storing air with low thermal conductivity, i.e., high thermal insulation properties, in the storage section 4, the thermal insulation properties of the fire spread prevention sheet 1 can be further improved.

[0022] When the fire spread prevention sheet 1 is sandwiched between heat sources or between a heat source and another component (e.g., a housing housing the heat source), it is compressed in the thickness direction as the heat source expands. The air in the storage section 4 is pressurized by this compression. In this case, there is a risk that the pressurized air in the storage section 4 will leak through the gap between the first rubber sheet 2 and the second rubber sheet 3, damaging the bond between the two sheets 2 and 3. However, if there is a flow path (here, groove 5) that allows air to flow from the storage section 4 to the end of the second rubber sheet 3, the air in the storage section 4 will flow to the outside through the flow path, reducing the risk of the above-mentioned damage (see arrow A in Figure 1). When the fire spread prevention sheet 1 returns to its original thickness from the compressed state, air will enter from the outside through the through-holes 4a.

[0023] In this embodiment, the groove 5 is formed so as to extend to the end of the second rubber sheet 3 while connecting a plurality of storage sections 4. However, the groove 5 may be formed so as to extend from one storage section 4 to the end of the second rubber sheet 3.

[0024] Next, an example of a manufacturing method for the fire spread prevention sheet 1 will be described. The manufacturing method includes a first vulcanization step of vulcanizing the first curable rubber sheet in an uncured state of the first rubber sheet 2, a second vulcanization step of vulcanizing the second curable rubber sheet in an uncured state of the second rubber sheet 3, and a post-cure lamination step of laminating the first rubber sheet 2 and the second rubber sheet 3 together. Examples of molding methods include a molding method using a mixing roll, a calendar molding method, and a press molding method. When a cured adhesive layer is provided between the first rubber sheet 2 and the second rubber sheet 3, it is preferable that the cured layer have a higher softening temperature than the first rubber sheet 2 and the second rubber sheet 3.

[0025] Second Embodiment FIG. 2 shows a perspective view of a fire spread prevention sheet according to a second embodiment and an enlarged view of a part Y of the side surface thereof.

[0026] The fire spread prevention sheet 1a according to this embodiment has a configuration in which a second rubber sheet 3 is sandwiched between two first rubber sheets 2. Other structures and materials of the fire spread prevention sheet 1a are the same as those of the fire spread prevention sheet 1. Below, the differences between the fire spread prevention sheet 1a and the fire spread prevention sheet 1 will be further explained.

[0027] The grooves 5 are formed on both sides in the thickness direction of the second rubber sheet 3. As a result, when the fire spread prevention sheet 1a is compressed from both sides in the thickness direction, the air in the through holes 4a passes through the grooves 5 and is discharged to the outside from the end of the second rubber sheet 3. Furthermore, when the fire spread prevention sheet 1a returns to its original thickness from the compressed state, air enters the through holes 4a from the outside.

[0028] <Third embodiment> FIG. 3 shows a perspective view of a fire spread prevention sheet according to a third embodiment.

[0029] The fire spread prevention sheet 1b according to this embodiment has recesses 4b, which are an example of one or more storage sections 4, in the second rubber sheet 3. The recesses 4b are recessed in the thickness direction of the second rubber sheet 3 and do not penetrate through the thickness direction. If there is a flow path (here, a groove 5) that allows air to flow from the recesses 4b to the end of the second rubber sheet 3, the air in the recesses 4b will flow to the outside via the flow path (see arrow A in Figure 3). Note that when the fire spread prevention sheet 1b returns to its original thickness from a compressed state, air will enter the recesses 4b from the outside. Other structure and materials of the fire spread prevention sheet 1b are the same as those of the fire spread prevention sheet 1.

[0030] <Fourth embodiment> FIG. 4 shows a perspective view of a fire spread prevention sheet according to a fourth embodiment.

[0031] The fire spread prevention sheet 1c according to this embodiment has a configuration in which a second rubber sheet 3 is sandwiched between two first rubber sheets 2. That is, the fire spread prevention sheet 1c includes another first rubber sheet 2 in addition to the fire spread prevention sheet 1b, and has a configuration in which the first rubber sheet 2, the second rubber sheet 3, and the first rubber sheet 2 are laminated in this order. The other structures and materials of the fire spread prevention sheet 1c are the same as those of the fire spread prevention sheet 1b. Below, the differences between the fire spread prevention sheet 1c and the fire spread prevention sheet 1 will be further explained.

[0032] The grooves 5 are formed on both sides in the thickness direction of the second rubber sheet 3. As a result, when the fire spread prevention sheet 1c is compressed from both sides in the thickness direction, the air in the recesses 4b passes through the grooves 5 and is discharged to the outside from the end of the second rubber sheet 3. Furthermore, when the fire spread prevention sheet 1c returns to its original thickness from the compressed state, air enters the recesses 4b from the outside.

[0033] 2. Battery First Embodiment FIG. 5 shows a longitudinal cross-sectional view of the battery according to the first embodiment and an enlarged view of one fire spread prevention sheet sandwiched between battery cells in the longitudinal cross-sectional view.

[0034] The battery 10 according to this embodiment is, for example, a battery for an electric vehicle, and includes a plurality of battery cells (also simply referred to as "cells") 20 arranged side by side. In this embodiment, the number of battery cells 20 is eight, but may be two to seven, or nine or more. The battery 10 is a storage battery, preferably a lithium-ion battery. The battery 10 includes a housing 11 with a bottom that is open on one side. The battery cells 20 are arranged inside 12 of the housing 11. The plurality of battery cells 20 are preferably pressed against each other by compressive force applied from both sides of the housing 11 using screws or the like (not shown). The bottom of the housing 11 is provided with through-holes 13 for flowing cooling water, which is an example of a coolant. The coolant may also be referred to as a cooling medium or a coolant. The battery cells 20 are arranged inside the housing 11 with fire-prevention sheets 1, 1b sandwiched between adjacent battery cells 20. Note that FIG. 5 omits the openings of the flow paths exposed at the end surfaces of the fire-prevention sheets 1, 1b. The same applies to Fig. 6. Hereinafter, in this embodiment, the fire spread prevention sheets 1 and 1b will be referred to as "fire spread prevention sheet 1" as a representative.

[0035] As described above, the battery 10 according to the first embodiment includes a plurality of battery cells 20 in a housing 11, and includes a fire spread prevention sheet 1 between the battery cells 20 and between the battery cells 20 and the housing 11, at least between the battery cells 20. The fire spread prevention sheet 1 is disposed with its thickness direction sandwiched between the battery cells 20 and between the battery cells 20 and the housing 11. The fire spread prevention sheet 1 is disposed so that its length direction coincides with the length direction of the battery cells 20 (the vertical direction in the drawing) or the width direction of the battery cells 20 (the front-to-back direction in the drawing). The fire spread prevention sheet 1 does not have to be disposed between the battery cells 20 and the housing 11.

[0036] The fire spread prevention sheet 1, which is disposed between the battery cells 20, is a sheet formed by laminating a first rubber sheet 2 and a second rubber sheet 3 in its thickness direction. The fire spread prevention sheet 1 is sandwiched and compressed between the battery cells 20 when the battery cells 20 are set in the housing 11, and even if the situation of subsequent release of compression is repeated many times, it elastically deforms in its thickness direction and easily recovers to its original thickness. Furthermore, the fire spread prevention sheet 1 is compressed in its thickness direction when stored in the housing 11 in a compressed state between the battery cells 20, and is further compressed when the battery cells 20 heat and expand during charging and / or discharging of the battery 10. Because the first rubber sheet 2 is a porous sheet, when sandwiched and compressed between the battery cells 20, it reduces in thickness more significantly than the second rubber sheet 3. When the fire spread prevention sheet 1 is subjected to greater pressure due to the overheating and expansion of the battery cells 20, the second rubber sheet 3 reduces in thickness more significantly than the first rubber sheet 2. The fire spread prevention sheet 1 has the function of preventing the spread of fire by reducing heat transfer from an overheated battery cell 20 to an adjacent battery cell 20 when the battery cell 20 overheats, and preferably has the function of being easily deformed in response to multiple stages of compression within the battery 10 and being able to maintain adhesion to the battery cells 20.

[0037] Second Embodiment FIG. 6 shows a longitudinal cross-sectional view of a battery according to a second embodiment and an enlarged view of one fire spread prevention sheet sandwiched between battery cells in the longitudinal cross-sectional view.

[0038] Unlike the battery 10 according to the first embodiment, the battery 10a according to this embodiment includes fire spread prevention sheets 1a and 1c with a three-layer structure in which a second rubber sheet 3 is sandwiched between two first rubber sheets 2. Hereinafter, in this embodiment, the fire spread prevention sheets 1a and 1c will be collectively referred to as the "fire spread prevention sheet 1a." When the fire spread prevention sheet 1a with a three-layer structure is used, even if pressure due to the expansion of the battery cells 20 is applied to both sides of the sheet 1a, the thickness of the first rubber sheet 2 can be reduced to better absorb that pressure.

[0039] <Third embodiment> FIG. 7 shows a longitudinal cross-sectional view of a battery according to a third embodiment and an enlarged view of one fire spread prevention sheet sandwiched between battery cells in the longitudinal cross-sectional view.

[0040] Unlike the batteries 10 and 10a according to the previous embodiments, the battery 10b according to this embodiment has a structure in which a large number of battery cells are stacked in a substantially horizontal position. Even in the battery 10b having such a structure, at least one of the fire spread prevention sheets 1, 1a, 1b, and 1c can be provided between the battery cells 20 and between the battery cells 20 and the housing 11. The other configuration of the battery 10b is the same as that of the batteries 10 and 10a, and therefore a redundant description will be omitted.

[0041] 3. Other embodiments Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and can be practiced in various modified forms.

[0042] For example, the flow path is not limited to the groove 5, and may be, for example, a tunnel-shaped flow path that runs from the storage section 4 through the inside of the second rubber sheet 3 to the end.

[0043] The grooves 5 may be formed on a surface of the second rubber sheet 3 other than the surface facing the first rubber sheet 2. However, it is preferable that the grooves 5 are always formed on the facing surface. Furthermore, the flow paths represented by the grooves 5 may be formed to extend in either the length direction or width direction of the fire spread prevention sheets 1, 1a, 1b, 1c. Furthermore, the fire spread prevention sheets 1, 1a, 1b, 1c may be formed to extend in multiple directions, not just in one of the length direction or width direction. Furthermore, the shape of the flow paths is not limited to a linear shape, and may be any shape such as a bent shape or a curved shape.

[0044] The features of the claims may be combined in any combination except where they are incombinable with one another. [Industrial Applicability]

[0045] The present invention can be used in the field of preventing the spread of fire caused by an overheated state of a heat source. [Explanation of symbols]

[0046] 1, 1a, 1b, 1c... Fire prevention sheet, 2... First rubber sheet, 3... Second rubber sheet, 4... Storage section, 4a... Through hole (an example of a storage section), 4b... Recess (an example of a storage section), 5... Groove (an example of a flow path), 10, 10a, 10b... Battery, 11... Housing, 20... Battery cell (an example of a heat source).

Claims

1. A fire prevention sheet that is disposed at least between a plurality of heat sources and that can prevent the spread of fire by suppressing heat transfer to other heat sources when the heat sources are in an overheated state, a porous first rubber sheet; a second rubber sheet made of solid material; and the second rubber sheet includes one or more storage sections capable of storing air, and a flow path for passing air from the storage sections toward an end of the second rubber sheet, The fire spread prevention sheet is characterized in that the storage portion is a through hole that penetrates the second rubber sheet in the thickness direction or a recess that is recessed in the thickness direction.

2. A plurality of the storage sections are provided, 2. The fire spread prevention sheet according to claim 1, wherein the flow path is formed by connecting the plurality of storage portions and extending to an end of the second rubber sheet.

3. 3. The fire spread prevention sheet according to claim 1, wherein the second rubber sheet is sandwiched between two of the first rubber sheets.

4. 3. The fire spread prevention sheet according to claim 1, wherein the flow path is a groove formed on at least one surface of the second rubber sheet in the thickness direction.

5. 4. The fire spread prevention sheet according to claim 3, wherein the grooves are formed on a surface facing the first rubber sheet.

6. 3. The fire spread prevention sheet according to claim 1, wherein the first rubber sheet and the second rubber sheet are made of silicone rubber.

7. A battery having a plurality of battery cells in a housing, A battery comprising the fire spread prevention sheet according to claim 1 or 2, at least between the battery cells, among between the battery cells and between the battery cells and the housing.

8. A battery having a plurality of battery cells in a housing, A battery comprising the fire spread prevention sheet according to claim 4 at least between the battery cells, among between the battery cells and between the battery cells and the housing.

9. A battery having a plurality of battery cells in a housing, A battery comprising the fire spread prevention sheet according to claim 6 at least between the battery cells, among between the battery cells and between the battery cells and the housing.

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