Battery cushioning material, battery, and method for managing gas generated by elastic member of battery cushioning material

Abstract

To provide a cushioning material for a battery with an increased commercial value.SOLUTION: A cushioning material 30 for a battery is disposed between adjacent battery cells 20. The cushioning material 30 for the battery includes an elastic member 32 and a heat-resistant bag 34 that encases the elastic member 32, and when the elastic member 32 generates gas, the heat-resistant bag 34 prevents the gas from coming into contact with the cell when the gas exceeds a predetermined concentration.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a battery cushioning material, a battery, and a method for sealing gas generated by an elastic member of a battery cushioning material. [Background technology]

[0002] Patent Document 1 discloses a battery cushioning material that is placed between adjacent battery cells in a battery that includes multiple battery cells. By placing the battery cushioning material between the adjacent battery cells, it is possible to absorb volume changes of the battery cells that occur during charging and discharging. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2023 / 199820 Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention has been made in view of the above circumstances, and one exemplary purpose of an embodiment of the present invention is to provide a cushioning material for a battery with improved commercial value. [Means for solving the problem]

[0005] In order to solve the above problems, a cushioning material for a battery according to one embodiment of the present invention is a cushioning material for a battery disposed between adjacent battery cells, and includes an elastic member and a heat-resistant bag enclosing the elastic member. When the elastic member generates gas, the heat-resistant bag prevents the gas from coming into contact with the cell if the gas exceeds a predetermined concentration.

[0006] Another aspect of the present invention is a battery, which includes a plurality of battery cells and the above-described battery cushioning material disposed between adjacent battery cells.

[0007] Yet another aspect of the present invention is a method for managing gas generated by an elastic member of a cushioning material for a battery, the method comprising: trapping the gas in a heat-resistant bag that encases the elastic member when the elastic member generates gas;

[0008] Yet another aspect of the present invention is also a method for managing gas generated by an elastic member of a cushioning material for a battery, the method comprising: a step of discharging gas generated by an elastic member of a cushioning material for a battery disposed between adjacent battery cells; the cushioning material for a battery including an elastic member and a heat-resistant bag enclosing the elastic member; and a step of discharging the gas to a position where the gas, exceeding a predetermined concentration, does not come into contact with the cells when the elastic member generates gas.

[0009] Yet another aspect of the present invention is also a method for managing gas generated by an elastic member of a cushioning material for a battery, the method comprising: a battery cushioning material disposed between adjacent battery cells; the battery cushioning material including an elastic member and a heat-resistant bag enclosing the elastic member; and a method for discharging gas generated by the elastic member to a position where the gas does not come into contact with the cells. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a cushioning material for a battery with increased commercial value. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram showing an example of a battery including a cushioning material for a battery according to a first embodiment. [Figure 2] 2(a) and 2(b) are diagrams showing the cushioning material for a battery according to the first embodiment. [Figure 3] 1A and 1B are diagrams illustrating a state in which a cushioning material for a battery according to a first embodiment is used. [Figure 4]FIG. 1 is a diagram showing a state of a battery cell and its surroundings when the battery cell becomes hot. [Figure 5] 5(a) and 5(b) are diagrams showing a cushioning material for a battery according to the second embodiment. [Figure 6] 10A and 10B are diagrams showing a state in which a cushioning material for a battery according to a second embodiment is used. [Figure 7] 10A to 10C are diagrams illustrating an example of a method for manufacturing a heat-resistant bag when the heat-resistant bag body and the duct are integrally formed. [Figure 8] FIG. 10 is a diagram showing an example of a battery including a buffer material for a battery according to a first modified example of the second embodiment. [Figure 9] 2. A cushioning material for a battery according to a second modification of the second embodiment [Figure 10] FIG. 10 is a diagram showing a state in which a cushioning material for a battery according to a second modified example of the second embodiment is used. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will be described below based on preferred embodiments with reference to the drawings. The embodiments are illustrative and do not limit the invention, and all features and combinations described in the embodiments are not necessarily essential to the invention. The same or equivalent components, parts, and processes shown in each drawing are designated by the same reference numerals, and redundant descriptions will be omitted where appropriate.

[0013] 1 is a diagram showing an example of a battery 1 including a battery cushioning material 30 according to the first embodiment. The battery 1 is, for example, a lithium-ion battery, a nickel-metal hydride battery, or an all-solid-state battery. In this embodiment, the battery 1 includes a restraint 10, a plurality of battery cells 20, and a plurality of battery cushioning materials 30.

[0014] The restraint 10 includes a case 11 and a pair of clamping members 12. The case 11 is formed in a tubular shape with both ends open. The case 11 is formed in a tubular shape with both ends open. The case 11 may be formed in a cylindrical shape with a circular cross section, or in a rectangular tubular shape with a polygonal (e.g., rectangular) cross section. The case 11 is made of, for example, metal or the like.

[0015] A stack of multiple battery cells 20 and multiple battery cushioning materials 30 stacked alternately is housed inside the case 11. The stacking direction of the stack (the left-right direction in FIG. 1) coincides with the direction parallel to the central axis of the cylindrical case 11 (i.e., the axial direction).

[0016] The pair of clamping members 12 are arranged to close the openings at both ends of the case 11, and are fixed to the case 11 by screws or the like. The pair of clamping members 12 clamp the stack in the stacking direction. The pair of clamping members 12 are made of, for example, metal.

[0017] The battery cell 20 is the smallest structural unit of a battery such as a lithium-ion battery. The battery cell 20 includes an exterior casing 21 and battery elements (not shown) enclosed within the exterior casing 21. The battery elements include, for example, a positive electrode, a negative electrode, a separator, and an electrolyte. The battery cell 20 may be a laminated (pouch) battery cell in which the exterior casing 21 is in the form of a film, or may be a rectangular or cylindrical battery cell.

[0018] The battery cushioning material 30 is disposed between adjacent battery cells 20. As shown in the figure, one battery cushioning material 30 may be disposed between adjacent battery cells 20, or multiple stacked battery cushioning materials 30 may be disposed. In either case, by disposing the battery cushioning material 30 between adjacent battery cells 20, the distance between the adjacent battery cells 20 can be ensured.

[0019] By ensuring a distance between adjacent battery cells 20, heat transfer from one battery cell 20 to the adjacent battery cell 20 can be suppressed.

[0020] The thicker the battery cushioning material 30, specifically the thicker the elastic member 32 described below in the stacking direction, the greater the distance between adjacent battery cells 20. In other words, the distance between adjacent battery cells 20 can be adjusted by adjusting the thickness of the elastic member 32 in the stacking direction.

[0021] The battery cushioning material 30 is disposed between the battery cell 20 and the clamping member 12. As shown in the figure, one battery cushioning material 30 may be disposed between the battery cell 20 and the clamping member 12, or multiple stacked battery cushioning materials 30 may be disposed.

[0022] The battery cells 20 expand when charged and contract when discharged. In other words, the volume of the battery cells 20 changes as they are charged and discharged. In contrast, the battery cushioning material 30 is elastically deformable, as will be described in detail later, and uses this elasticity to absorb the volume change of the battery cells 20. This prevents the battery 1 from being damaged by the volume change of the battery cells 20.

[0023] Fig. 2 is a diagram showing the battery cushioning material 30. Fig. 2(a) is a diagram showing the battery cushioning material 30 as seen in the stacking direction, and Fig. 2(b) is a view as seen from the arrow A in Fig. 2(a). Fig. 3 is a diagram showing the battery cushioning material 30 in use. The cross-sectional view of the battery cushioning material 30 in Fig. 3 corresponds to the cross-sectional view taken along line BB in Fig. 2(b).

[0024] The battery cushioning material 30 includes an elastic member 32 and a heat-resistant bag 34 .

[0025] The elastic member 32 is formed in a plate shape. The material of the elastic member 32 is not particularly limited as long as it is elastically deformable, that is, can absorb the volume change of the battery cell 20.

[0026] Here, "elastically deformable" means having flexibility that allows deformation and recovery. Specifically, for example, it means having flexibility that allows deformation even in response to an external force caused by a volume change of the battery cell 20, and having recovery ability that allows the battery to return to its original shape when the external force is removed after deformation due to the external force. Note that the original shape here is not limited to a shape that is completely the same as before deformation due to the external force, but also includes a shape that is approximately the same as before deformation due to the external force.

[0027] For example, the material of the elastic member 32 may be rubber, a resin-based elastomer, fibers such as nonwoven fabric, inorganic particles, inorganic fibers, or a heat insulating material containing an organic binder or the like.

[0028] The elastic member 32 may be a porous body. Specifically, the elastic member 32 may be, for example, a foam body. Furthermore, the elastic member 32 may be, for example, a porous body having a honeycomb structure. When the elastic member 32 is a porous body, it is easy to exhibit elasticity, and a sudden increase in pressure can be suppressed. Furthermore, since the elastic member 32 contains a large amount of air, heat transfer from one battery cell 20 to another battery cell 20 via the elastic member 32 can be suppressed.

[0029] The elastic member 32 preferably has a high compressibility. In this case, the increase in reaction force is small even if the amount of compression of the elastic member 32 increases. When the elastic member 32 is a foam, the foaming rate may be determined based on the desired compressibility.

[0030] The heat-resistant bag 34 encases the entire elastic member 32. The heat-resistant bag 34 is airtight and seals the entire elastic member 32. As a result, even if the elastic member 32 undergoes a decomposition reaction (for example, thermal decomposition) and gas is generated, the gas is trapped in the heat-resistant bag 34 and does not leak out of the heat-resistant bag 34.

[0031] The heat-resistant bag 34 is configured to be deformable in response to the deformation of the elastic member 32 when the elastic member 32 deforms. Therefore, the heat-resistant bag 34 is configured to at least allow the deformation of the elastic member 32. The heat-resistant bag 34 is preferably configured not to hinder the deformation of the elastic member 32. In other words, the heat-resistant bag 34 is preferably configured to have the same or lower rigidity as the elastic member 32, i.e., to have rigidity equal to or less than that of the elastic member 32. To achieve this, the heat-resistant bag 34 may be formed to be thinner than at least the elastic member 32.

[0032] The heat-resistant bag 34 may have a bulge. That is, the volume of the heat-resistant bag 34 when fully inflated with gas may be larger than the volume of the elastic member 32. In this case, the thickness of the battery cushioning material 30 in the stacking direction when the heat-resistant bag 34 is fully inflated is greater than the original thickness of the battery cushioning material 30, i.e., before the elastic member 32 generates gas and the heat-resistant bag 34 inflates. Therefore, when the heat-resistant bag 34 is fully inflated, the distance between the two battery cells 20 sandwiching the battery cushioning material 30 is longer than the original distance, i.e., before the elastic member 32 generates gas and the heat-resistant bag 34 inflates. This further suppresses heat transfer between the two battery cells 20 sandwiching the battery cushioning material 30.

[0033] The heat-resistant bag 34 may have higher thermal insulation properties than the elastic member 32. In this case, compared to when the battery cushioning material 30 does not include the heat-resistant bag 34, heat is less likely to be transmitted to the elastic member 32, and therefore the elastic member 32 is less likely to reach a high temperature, and therefore the elastic member 32 is less likely to undergo a decomposition reaction, i.e., to generate gas.

[0034] The heat-resistant bag 34 may have the same or lower thermal insulation properties as the elastic member 32. In this case, because heat is easily transferred to the elastic member 32, the elastic member 32 is likely to reach a high temperature, and therefore the elastic member 32 is likely to undergo a decomposition reaction, i.e., to generate gas, and the heat-resistant bag 34 becomes swollen with the generated gas, thereby ensuring a distance between adjacent battery cells 20, as will be described in detail later.

[0035] The heat-resistant bag 34 has a heat-resistant temperature that is higher than the lowest temperature at which the elastic member 32 undergoes a decomposition reaction (thermal decomposition) and generates gas. The heat-resistant temperature here may be a temperature at which the heat-resistant bag 34 can maintain its shape. For example, the heat-resistant temperature may be (A) or higher.

[0036] For example, when the lower limit temperature of the elastic member 32 is the first temperature, i.e., when the elastic member 32 generates gas at or above the first temperature, the heat-resistant bag 34 preferably has a heat-resistant temperature that is at least higher than the first temperature. As a result, even if the elastic member 32 undergoes a decomposition reaction and generates gas, as long as the heat-resistant bag 34 is at or below the heat-resistant temperature, the heat-resistant bag 34 can maintain its shape, and the gas is sealed in the heat-resistant bag 34.

[0037] The heat-resistant bag 34 may be made of metal. In this case, a high heat-resistant temperature can be achieved. For example, the heat-resistant bag 34 may be made of aluminum, copper, stainless steel, or tungsten. The metal used for the heat-resistant bag 34 may be determined depending on the heat-resistant temperature required for the heat-resistant bag 34.

[0038] The heat-resistant bag 34 may be formed by stacking two metal sheets to sandwich the elastic member 32 and sealing their edges. Alternatively, the heat-resistant bag 34 may be formed by folding a single metal sheet in half to sandwich the elastic member 32 and sealing its edges. In this case, the thickness of the metal sheets is not particularly important. The joining method is also not particularly important. For example, the joining method may be a known joining method such as welding, pressure welding, or ultrasonic welding, or a joining method that will be available in the future. However, if gas is generated from the elastic member 32, the internal pressure of the heat-resistant bag 34 will increase, so the heat-resistant bag 34 needs to have a thickness and joining strength that can withstand this internal pressure. In other words, the heat-resistant bag 34 needs to be thick enough to withstand the internal pressure and have a joining strength that will not come apart due to the internal pressure.

[0039] Next, the effects of this embodiment will be described. Fig. 4 is a diagram showing the state of a certain battery cell 20_i and its surroundings when the battery cell 20_i of the battery 1 becomes hot. In Fig. 4, heat from the battery cell 20_i is transferred to the elastic members 32_i and 32_i+1 of the battery cushioning materials 30_i and 30_i+1 adjacent to the battery cell 20_i, causing a decomposition reaction in the elastic members 32_i and 32_i+1, and generating gas from the elastic members 32_i and 32_i+1.

[0040] Even if gas is generated from the elastic members 32_i, 32_i+1, the elastic members 32_i, 32_i+1 are sealed by the heat-resistant bags 34_i, 34_i+1, so the gas is confined in the heat-resistant bags 34_i, 34_i+1 and does not leak out of the heat-resistant bags 34_i, 34_i+1. Therefore, the gas cannot come into contact with the battery cell 20_i. In other words, although it is undesirable for the gas generated from the elastic members 32_i, 32_i+1 to come into contact with the battery cell 20_i, the gas is managed by the heat-resistant bags 34_i, 34_i+1 to prevent it from coming into contact with the battery cell 20_i.

[0041] Furthermore, the elastic members 32_i, 32_i+1 that are heated to the point where a decomposition reaction occurs may lose their function as elastic members and remain compressed, never recovering. In response to this, the gas does not leak out of the heat-resistant bags 34_i, 34_i+1, so the internal pressure of the heat-resistant bags 34_i, 34_i+1 increases, causing the heat-resistant bags 34_i, 34_i+1 to become swollen with gas. This ensures a sufficient distance between the battery cell 20_i and the adjacent battery cells 20_i-1, 20_i+1, even when the battery cell 20_i becomes hot, thereby suppressing heat transfer from the battery cell 20_i to the battery cells 20_i-1, 20_i+1. If the heat-resistant bags 34_i, 34_i+1 have a bulge, the heat-resistant bags 34_i, 34_i+1 will bulge to their full capacity, causing the battery cushioning materials 30_i, 30_i+1 to become larger than before, i.e., thicker in the stacking direction than before, and the distance between the battery cell 20_i and the battery cells 20_i-1, 20_i+1 will also become longer than before.

[0042] By adjusting the amount of elastic member 32, the amount of gas generated when the elastic member 32 undergoes a decomposition reaction, and therefore the internal pressure of heat-resistant bag 34, can be adjusted.

[0043] (Second embodiment) Fig. 5 is a diagram showing a battery cushioning material 130 according to a second embodiment. Fig. 5(a) is a diagram showing the battery cushioning material 130 as seen in the stacking direction, and Fig. 5(b) is a view as seen from the arrow C in Fig. 5(a). Fig. 6 is a diagram showing the battery cushioning material 130 in use. The cross-sectional view of the battery cushioning material 130 in Fig. 6 corresponds to the cross-sectional view taken along line DD in Fig. 5(a).

[0044] The battery cushioning material 130 is configured in the same manner as the battery cushioning material 30 according to the first embodiment, except that the heat-resistant bag 34 has an outlet 34a. The following description will focus on the differences from the first embodiment, and will omit a description of the commonalities as appropriate.

[0045] The heat-resistant bag 34 has an outlet 34a for discharging gas, and seals the entire elastic member 32 so that gas is not discharged from any other place than the outlet 34a. The number of outlets 34a is not important. There may be one outlet 34a, or two or more outlets 34a (i.e., multiple outlets).

[0046] The heat-resistant bag 34 includes a heat-resistant bag main body 134 that seals the entire elastic member 32, and a duct 136 that connects the inside and outside of the heat-resistant bag main body 134. The outlet of the duct 136 forms an exhaust port 34a. The duct 136 connects the inside of the heat-resistant bag 34 to the outside of the battery 1. Specifically, one end 136a of the duct 136 is connected to the heat-resistant bag 34. The other end 136b of the duct 136, i.e., the exhaust port 34a serving as the outlet, is located outside the battery 1. That is, the heat-resistant bag 34 has the exhaust port 34a in a position where gas discharged from the exhaust port 34a does not come into contact with the battery cells 20. As a result, when a decomposition reaction occurs in the elastic member 32 and gas is generated, the gas does not leak into the inside of the case 11, i.e., does not come into contact with the battery cells 20, but is released to the outside of the battery 1 through the duct 136.

[0047] The material of the duct 136 is not particularly limited, but preferably, like the heat-resistant bag body 134, it has a heat-resistant temperature higher than the lower limit temperature at which the elastic member 132 undergoes a decomposition reaction and generates gas.

[0048] The duct 136 may be formed separately from the heat-resistant bag body 134 and then joined to the heat-resistant bag body 134 .

[0049] The duct 136 may be formed from the same material as the heat-resistant bag body 134. In this case, the duct 136 may be formed integrally with the heat-resistant bag body 134.

[0050] FIG. 7 illustrates an example of a manufacturing method for the heat-resistant bag 34 when the heat-resistant bag main body 134 and the duct 136 are integrally formed. In this example, the heat-resistant bag 34 is formed by overlapping two metal sheets 140 and joining their peripheries. The sheet 140 has a first sheet portion 144 that constitutes the heat-resistant bag main body 134 and a second sheet portion 146 that protrudes from the first sheet portion 144 and constitutes the duct 136. The first sheet portion 144 is rectangular in shape in the illustrated example, although not particularly limited thereto. The second sheet portion 146 is elongated and rectangular in shape in the illustrated example, although not particularly limited thereto. The heat-resistant bag 34, i.e., the heat-resistant bag main body 134 and the duct 136, are formed by joining the peripheries of the two sheets 140, excluding the tip portion 146a of the second sheet portion 146. In FIG. 7, the joining portion (joint line) of the two sheets is indicated by a dashed line.

[0051] In this case, there is no seam between heat-resistant bag body 134 and duct 136, so gas does not leak between heat-resistant bag body 134 and duct 136. Also, because heat-resistant bag body 134 and duct 136 can be formed at one time, labor costs are lower and tact time can be shortened compared to when they are formed separately and then joined.

[0052] 5 and 6. As in the first embodiment, the elastic member 32 may be made of any material as long as it is elastically deformable, that is, capable of absorbing the volumetric changes of the battery cells 20. However, if the elastic member 32 is porous, gas will flow easily through the heat-resistant bag 34, and therefore the gas will be easily discharged.

[0053] Next, the effects of this embodiment will be described. According to this embodiment, even if a certain battery cell 20 becomes hot and the battery cushioning material 130 adjacent to that battery cell 20 is heated, causing gas to be generated from the elastic member 32, the gas is not discharged from anywhere other than the outlet 34a. In other words, the gas is discharged directly to the outside of the battery 1 and does not leak into the inside of the case 11. Therefore, the gas cannot come into contact with the battery cell 20. In other words, the gas generated from the elastic member 32 is managed by the heat-resistant bag 34 so as not to come into contact with the battery cell 20.

[0054] Furthermore, according to this embodiment, the gas is released to the outside of the battery 1 through the duct 136, which prevents an excessive increase in the internal pressure of the heat-resistant bag 34. This reduces the risk of damage to the heat-resistant bag 34. Alternatively, as described in the first embodiment, when the heat-resistant bag 34 is formed by joining the edges of two sheets of metal foil or one sheet of metal foil folded in half, such a strong joining is not required.

[0055] (First modified example of the second embodiment) In the second embodiment, the duct 136 connects the inside of the heat-resistant bag 34 with the outside of the battery 1, and the gas generated by the elastic member 102 is released to the outside of the battery 1. However, this is not limited to this, and the duct 136 may release the gas generated by the elastic member 102 into the inside of the battery 1 as long as the high concentration gas does not come into contact with the battery cell 20.

[0056] 8 is a schematic diagram showing a battery 1 according to a first modified example of the second embodiment. The following description will focus on the differences from the second embodiment, and will omit a description of the commonalities as appropriate.

[0057] In this modification, the battery 1 includes a plurality of battery cells 20, a plurality of battery cushioning materials 130, and a cooler 40 for cooling the plurality of battery cells 20.

[0058] The cooler 40 cools the battery cells 20 by discharging relatively high-temperature air from inside the battery 1 and drawing in relatively low-temperature air from outside the battery 1. The cooler 40 may include a cooling unit that cools the air drawn in from outside the battery 1. In either case, by providing the battery 1 with the cooler 40, an air flow is generated inside the battery 1, and the air inside the battery 1 is constantly replaced with air outside the battery 1.

[0059] In this modified example, the other end 136b of the duct 136, i.e., the outlet 34a which is the outlet, is located inside the battery 1. Therefore, when the elastic member 102 undergoes a decomposition reaction and generates gas, the gas is released into the battery 1. In this case, the outlet 34a is provided at a position where the gas discharged from the outlet 34a does not come into contact with the battery cells 20, or at a position where the concentration of the gas discharged from the outlet 34a falls below a predetermined concentration before it comes into contact with the battery cells 20. This prevents the gas from coming into contact with the battery cells 20, or ensures that only low-concentration gas comes into contact with the battery cells 20.

[0060] For example, as shown in the figure, the exhaust port 34a is located closer to the cooler 40 than to the battery cell 20. Specifically, the exhaust port 34a is located where the distance L1 between the exhaust port 34a and the cooler 40 and the distance L2 between the exhaust port 34a and the battery cell 20 closest to it satisfy the relationship distance L1 < distance L2. In this case, the gas generated by the decomposition reaction of the elastic member 32 is released to a position relatively far from the battery cell 20 but relatively close to the cooler 40, and is then exhausted to the outside of the battery 1.

[0061] Further, for example, the exhaust port 34a may be connected in communication with the cooler 40. In this case, the gas is released from the exhaust port 34a into the inside of the cooler 40, and then exhausted to the outside of the battery 1 from there.

[0062] Furthermore, for example, the exhaust port 34a may be located at a position that protrudes beyond the battery cells 20 in a direction perpendicular to the stacking direction (the up-down direction or depth direction in FIG. 8). In other words, as shown in FIG. 5(a), the exhaust port 34a may be located at the periphery of the heat-resistant bag 34 when the battery cushioning material is viewed in the stacking direction. In this case, because there is an air flow due to the cooler 40 at the exhaust port 34a, the gas is immediately diluted by the air and is exhausted to the outside of the battery 1 together with the air.

[0063] According to these modifications, the heat-resistant bag 34 is used to prevent gas from coming into contact with the battery cells 20, or to ensure that only low concentrations of gas come into contact with the battery cells 20.

[0064] (Second Modification of the Second Embodiment) Unlike the first modification of the second embodiment, the heat-resistant bag 34 does not have to include the duct 136 .

[0065] Fig. 9 is a diagram showing a battery cushioning material 130 according to a second modified example of the second embodiment. Fig. 9 corresponds to Fig. 5(a). Fig. 10 is a diagram showing the battery cushioning material 130 of Fig. 9 in use. Fig. 10 corresponds to Fig. 6. The cross-sectional view of the battery cushioning material 130 in Fig. 10 corresponds to the cross-sectional view taken along line EE in Fig. 9. The following description will focus on the differences from the first modified example of the second embodiment, and will omit a description of the commonalities as appropriate.

[0066] In this modified example, the heat-resistant bag 34 includes only the heat-resistant bag main body 134. In other words, the heat-resistant bag 34 does not include a duct. The exhaust port 34a is provided in the heat-resistant bag main body 134. In this case, the exhaust port 134a is provided at a position where the concentration of the gas exhausted from the exhaust port 34a falls below a predetermined concentration before it comes into contact with the battery cells 20. This ensures that only low-concentration gas comes into contact with the battery cells 20.

[0067] 9, the exhaust port 34a may be located on the periphery of the heat-resistant bag 34 when the battery cushioning material 130 is viewed in the stacking direction. In this case, since there is an air flow through the exhaust port 34a due to the cooler 40, the gas is immediately diluted by the air and is exhausted to the outside of the battery 1 together with the air.

[0068] In Fig. 9, a large number of discharge outlets 34a are provided along the periphery of the heat-resistant bag 34. However, more discharge outlets 34a may be provided along the periphery, with almost no gaps between them. In any case, the number of discharge outlets 34a is not particularly limited. In other words, there may be one discharge outlet 34a, or two or more (i.e., multiple) discharge outlets 34a.

[0069] According to this modification, the heat-resistant bag 34 manages so that only low-concentration gas comes into contact with the battery cell 20 .

[0070] The present invention has been described above based on an embodiment. This embodiment is merely an example, and it will be understood by those skilled in the art that various modifications are possible in the combination of the components and treatment processes, and that such modifications are also within the scope of the present invention.

[0071] The above-described embodiment can be generalized to provide the following aspects.

[0072] [Aspect 1] A cushioning material for a battery that is placed between adjacent battery cells, the cushioning material comprising an elastic member and a heat-resistant bag that encases the elastic member, wherein when the elastic member generates gas, the heat-resistant bag prevents the gas from coming into contact with the cell if the gas exceeds a predetermined concentration.

[0073] [Aspect 2] 2. The cushioning material for a battery according to claim 1, wherein the heat-resistant bag seals the elastic member to prevent the gas exceeding a predetermined concentration from coming into contact with the cell.

[0074] [Aspect 3] The heat-resistant bag has an expansion area, and when the elastic member generates gas, the gas causes the heat-resistant bag to expand, thereby making the distance between adjacent battery cells longer than when the heat-resistant bag is not expanded.

[0075] [Aspect 4] The heat-resistant bag has an exhaust outlet and seals the elastic member so that gas is not discharged from any other outlet, and the heat-resistant bag has the exhaust outlet at a position where the concentration of the gas discharged from the exhaust outlet falls below the predetermined concentration before it comes into contact with the cell, in order to prevent the gas from exceeding a predetermined concentration from coming into contact with the cell.

[0076] [Aspect 5] The heat-resistant bag has an exhaust outlet and seals the elastic member so that gas is not discharged from any other outlet, and the heat-resistant bag has the exhaust outlet in a position where the gas discharged from the exhaust outlet does not come into contact with the cell, so as to prevent the gas exceeding a predetermined concentration from coming into contact with the cell.

[0077] [Aspect 6] The battery cushioning material according to aspect 4 or 5, wherein the outlet is located on the periphery of the heat-resistant bag when the battery cushioning material is viewed in the direction in which the battery cushioning material should be stacked.

[0078] [Aspect 7] 7. The cushioning material for a battery according to any one of aspects 1 to 6, wherein the heat-resistant bag is made of metal.

[0079] [Aspect 8] Aspect 8. The cushioning material for a battery according to any one of aspects 1 to 7, wherein the heat-resistant temperature of the heat-resistant bag is higher than the lowest temperature at which the elastic member undergoes a decomposition reaction and generates gas.

[0080] [Aspect 9] A battery comprising a plurality of battery cells and the buffer material for a battery according to any one of claims 1 to 8, disposed between adjacent battery cells.

[0081] [Aspect 10] A method for managing gas generated by an elastic member of a cushioning material for a battery disposed between adjacent battery cells, the method comprising: trapping the gas in a heat-resistant bag that encases the elastic member when the elastic member generates gas.

[0082] [Aspect 11] Aspect 11. The method of aspect 10, wherein the heat-resistant bag trapping the gas comprises inflating the heat-resistant bag with the gas.

[0083] [Aspect 12] 12. The method of claim 11, wherein the expanding of the heat-resistant bag comprises expanding the heat-resistant bag to increase a distance between adjacent battery cells.

[0084] [Aspect 13] A method for managing gas generated by an elastic member of a cushioning material for a battery arranged between adjacent battery cells, the cushioning material for the battery comprising the elastic member and a heat-resistant bag enclosing the elastic member, and when the elastic member generates the gas, the method comprises discharging the gas to a position where the gas exceeding a predetermined concentration does not come into contact with the cell.

[0085] [Aspect 14] A method for managing gas generated by an elastic member of a cushioning material for a battery disposed between adjacent battery cells, the cushioning material for the battery comprising the elastic member and a heat-resistant bag enclosing the elastic member, and when the elastic member generates gas, the method comprises discharging the gas to a position where the gas does not come into contact with the cell. [Explanation of symbols]

[0086] 30,130 Battery cushioning material, 32 Elastic member, 34 Heat-resistant bag, 136 Duct.

Claims

1. A battery cushioning material disposed between adjacent battery cells, An elastic member; a heat-resistant bag that encases the elastic member; Equipped with The heat-resistant bag is a cushioning material for a battery that, when the elastic member generates gas, prevents the gas from coming into contact with the cell if the gas exceeds a predetermined concentration.

2. The cushioning material for a battery according to claim 1 , wherein the heat-resistant bag seals the elastic member so as to prevent the gas exceeding a predetermined concentration from coming into contact with the cell.

3. 3. The battery cushioning material of claim 2, wherein the heat-resistant bag has an expansion area, and when the elastic member generates gas, the heat-resistant bag expands due to the gas, thereby making the distance between adjacent battery cells longer than when the heat-resistant bag is not expanded.

4. the heat-resistant bag has an exhaust port, and the elastic member is sealed so that gas is not discharged from any other source than the exhaust port; The heat-resistant bag has an outlet at a position where the concentration of the gas discharged from the outlet falls below the predetermined concentration before it comes into contact with the cell, in order to prevent the gas exceeding a predetermined concentration from coming into contact with the cell.

5. the heat-resistant bag has an exhaust port, and the elastic member is sealed so that gas is not discharged from any other source than the exhaust port; 2. The cushioning material for a battery as described in claim 1, wherein the heat-resistant bag has an exhaust outlet at a position where the gas discharged from the exhaust outlet does not come into contact with the cell, so as to prevent the gas exceeding a predetermined concentration from coming into contact with the cell.

6. 6. The cushioning material for a battery according to claim 4, wherein the outlet is located at the periphery of the heat-resistant bag when the cushioning material for a battery is viewed in the direction in which the cushioning material for a battery is to be stacked.

7. The cushioning material for a battery according to claim 1 , wherein the heat-resistant bag is made of metal.

8. 2. The cushioning material for a battery according to claim 1, wherein the heat-resistant temperature of the heat-resistant bag is higher than the lowest temperature at which the elastic member undergoes a decomposition reaction and generates gas.

9. a plurality of battery cells; The cushioning material for a battery according to any one of claims 1 to 5, which is disposed between adjacent battery cells; A battery comprising:

10. A method for managing gas generated by an elastic member of a battery cushioning material disposed between adjacent battery cells, comprising: When the elastic member generates gas, a heat-resistant bag encasing the elastic member traps the gas.

11. The method of claim 10 , wherein the heat-resistant bag trapping the gas comprises the heat-resistant bag inflating with the gas.

12. The method of claim 11 , wherein expanding the thermally resistant bag comprises expanding the thermally resistant bag to increase a distance between adjacent battery cells.

13. A method for managing gas generated by an elastic member of a battery cushioning material disposed between adjacent battery cells, comprising: the battery cushioning material includes the elastic member and a heat-resistant bag that wraps the elastic member; When the elastic member generates the gas, the method comprises discharging the gas to a position where the gas does not come into contact with the cell at a concentration exceeding a predetermined concentration.

14. A method for managing gas generated by an elastic member of a battery cushioning material disposed between adjacent battery cells, comprising: the battery cushioning material includes the elastic member and a heat-resistant bag that wraps the elastic member; When the elastic member generates the gas, the gas is discharged to a position where the gas does not contact the cell.

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