Buffer structure for battery

Abstract

The invention provides a buffer structure for a battery, which can realize improvement of a buffer function. The battery buffer structure (100) comprises a buffer sheet (100) and sandwiching members (210, 220) disposed between the buffer sheet (100) and battery constituent members, and is characterized in that the buffer sheet (100) comprises protruding parts (120a, 120b) protruding toward the sandwiching members (210, 220).

Description

Technical Field

[0001] The present invention relates to a buffer structure for a battery. Background Art

[0002] In a battery configured as a single cell battery in which a plurality of single cells are stacked, the quality may sometimes deteriorate due to the expansion and contraction of the single cells. For example, in the case of a lithium ion battery, since the single cell expands and contracts during charge and discharge, if no countermeasures are taken, a load is applied to the electrode particles and they are broken, resulting in a short battery life. In addition, in the case of a all-solid-state battery, it is known that a deviation in surface pressure accompanying expansion and contraction becomes a deviation in performance and also affects the life. Therefore, there is a known technique of providing a buffer member between adjacent single cells, between a single cell and a frame, and between a supporting member to reduce the stress on the single cell.

[0003] In the case where the buffer member is a flat plate member, if the buffer member is compressed, even if the compression rate is low, the reaction force rapidly increases and a sufficient buffer effect cannot be obtained. In addition, in the case of a buffer member having a plurality of protrusions provided on a flat plate member, stress concentrates on the portion where the protrusions contact, and there is a concern about a reduction in battery performance. Thus, there is still room for improvement.

[0004] It should be noted that, for example, in the case of a lithium ion battery, when the calorific value of a specific single cell becomes high for some reason, the calorific value of other single cells also increases, and thermal runaway may occur. Therefore, there is also a known technique of making the buffer member have a heat insulating function.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2020-4556. Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] The present invention provides a buffer structure for a battery capable of improving the buffer function.

[0010] Means for Solving the Problems

[0011] The present invention employs the following means to solve the above problems.

[0012] That is, the buffer structure for a battery of the present invention includes:

[0013] a buffer sheet; and

[0014] a heat insulating member disposed between the buffer sheet and a battery component

[0015] The buffer structure for a battery is characterized in that,

[0016] the buffer sheet includes a protruding portion protruding toward the heat insulation member.

[0017] According to the present invention, a heat insulation member is provided between the buffer sheet and battery component parts (single battery, frame, support member, etc.), so that the stress generated by the protruding portion of the buffer sheet is dispersed by the heat insulation member. Thereby, stress concentration on the battery component parts caused by the protruding portion can be suppressed. In addition, in the present invention, since the heat insulation member is disposed between the buffer sheet and the battery component parts, heat transfer can be suppressed.

[0018] In addition, a buffer structure for a battery of another invention includes a buffer sheet and a clamping member, and the buffer structure for a battery is characterized in that,

[0019] the buffer sheet includes a protruding portion protruding toward the clamping member,

[0020] the clamping member has a stress dispersion function for dispersing the stress generated by the protruding portion.

[0021] According to the present invention, stress concentration on the battery component parts caused by the protruding portion can be suppressed by the clamping member having a stress dispersion function for dispersing the stress generated by the protruding portion.

[0022] Moreover, a buffer structure for a battery of other invention includes a buffer sheet and a clamping member,

[0023] the buffer structure for a battery is characterized in that,

[0024] the buffer sheet includes a protruding portion protruding toward the opposite side of the clamping member,

[0025] when the maximum thickness of the buffer sheet in the protruding direction of the protruding portion in a state where the buffer structure for a battery is compressed to a state where no external force is applied to the buffer structure for a battery becomes half, the back side of the foremost end portion of the protruding portion does not contact the clamping member and a space is maintained between the protruding portion and the clamping member.

[0026] According to the present invention, even when the buffer structure for a battery is compressed until the maximum thickness of the buffer sheet in the protruding direction of the protruding portion becomes half, a space can be maintained between the protruding portion and the clamping member, so that a sharp increase in the rebounding force of the buffer structure for a battery can be suppressed. In addition, there is also an effect of maintaining a heat insulation function by the air in the space.

[0027] It may be that a plurality of the protruding portions are respectively provided on both surfaces of the buffer sheet.

[0028] It may be that the protrusions provided on one surface of the buffer sheet and the protrusions provided on the other surface of the buffer sheet are alternately arranged vertically and horizontally.

[0029] It may be that the height of the protrusions provided on one surface of the buffer sheet is the same as the height of the protrusions provided on the other surface of the buffer sheet.

[0030] Thus, the functions on both sides of the buffer structure for the battery are the same, so there is no need to confirm the front and back sides during the installation operation of the buffer structure for the battery.

[0031] It may be that the maximum thickness of the buffer sheet in the protruding direction of the protrusion is more than three times the wall thickness of the buffer sheet.

[0032] It may be that the area surrounded by the outer shape of the cross-section perpendicular to the protruding direction of the protrusion gradually narrows toward the front end in the protruding direction.

[0033] Thus, it is possible to increase the volume inside the hollow portion and suppress a sharp rise in the elastic rebound force, and it is easy to maintain the space even when the buffer sheet is compressed. At the same time, the area of the front end of the protrusion can be reduced. Therefore, the contact area between the protrusions and the components in contact with the protrusions becomes smaller, and heat transfer can be suppressed.

[0034] It is also preferable that the buffer sheet and the heat insulation member (clamping member) are integrated.

[0035] In addition, the above-mentioned various structures can be combined and adopted as much as possible.

[0036] Advantages of the Invention

[0037] As described above, according to the present invention, the buffering function can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic structural diagram of a battery using the buffer structure for a battery according to Embodiment 1 of the present invention.

[0039] Figure 2 It is an external view of the buffer structure for a battery according to Embodiment 1 of the present invention.

[0040] Figure 3 It is a schematic cross-sectional view of the buffer structure for a battery according to Embodiment 1 of the present invention.

[0041] Figure 4 It is an operation explanatory diagram of the buffer structure for a battery according to Embodiment 1 of the present invention.

[0042] Figure 5 It is an explanatory diagram of the buffer structure for a battery according to Embodiment 2 of the present invention.

[0043] Figure 6 FIG. is a diagram showing various examples of the protrusion related to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0044] Hereinafter, a mode for carrying out the present invention will be illustratively and detailedly described with reference to the accompanying drawings based on embodiments. However, as long as there is no specific description of the dimensions, materials, shapes, relative arrangements, etc. of the constituent members described in this embodiment, it is not intended to limit the scope of the present invention only to them.

[0045] (Embodiment 1)

[0046] Refer to Figures 1 to 4 A buffer structure for a battery according to Embodiment 1 of the present invention will be described. Figure 1 FIG. is a schematic structural diagram of a battery using the buffer structure for a battery according to Embodiment 1 of the present invention. Figure 2 FIG. is an external view of the buffer structure for a battery according to Embodiment 1 of the present invention. (a) is a top view of the buffer structure for a battery, and (b) is a side view of the buffer structure for a battery. Figure 3 FIG. is a schematic cross-sectional view of the buffer structure for a battery according to Embodiment 1 of the present invention. Figure 3 In (a) of Figure 2 is a cross-sectional view taken along line AA in (a) of Figure 3 In (b) of Figure 4 is a schematic cross-sectional view showing a state in which a compressive force acts on the buffer structure for a battery, and (b) is a graph showing the relationship between the compression ratio and the surface pressure.

[0047] <Battery>

[0048] Specifically, refer to Figure 1 to describe an example of a battery to which the buffer structure for a battery according to this embodiment can be applied. Here, a lithium ion battery will be described as an example. The battery 1 is composed of a battery pack in which a plurality of single cells 20 are stacked, and the battery pack is supported by a frame (frame wall surface) for housing the battery pack, a support member for supporting the battery pack, and the like. In Figure 1 In (a) of

[0049] In battery 1, in order to suppress the stress acting on single cell 20 due to the expansion and contraction of single cell 20 during charge and discharge, a battery buffer structure 10 is provided between adjacent single cells 20 and between single cell 20 and the housing (or support member) 30. In addition, the battery buffer structure 10 can be arranged separately for each single cell 20, or can be arranged separately for multiple single cells 20. Further, multiple battery buffer structures 10 can be used overlappingly between adjacent single cells 20 and between single cell 20 and the housing (or support member) 30.

[0050] In addition, in Figure 1 In the battery 1X shown in (b) of , a single cell group 20X is accommodated inside the housing 30X. In addition, the housing 30X is supported by a pair of support members 30Y. In the example shown in this figure, a battery buffer structure 10 is provided between the housing 30X and the support member 30Y. In addition, although not particularly shown, in the single cell group 20X, a battery buffer structure can also be provided between adjacent single cells.

[0051] With the battery 1 configured as described above, when the single cell 20 expands, even if a compressive force acts on the single cell 20, the stress on the single cell 20 can be suppressed by the battery buffer structure 10. In addition, in the case of a lithium-ion battery, countermeasures against thermal runaway are required, and thus the battery buffer structure 10 is configured to have a heat insulation function.

[0052] <Battery buffer structure>

[0053] The battery buffer structure 10 will be described in detail. The battery buffer structure 10 includes a buffer sheet 100, and clamping members 210 and 220 disposed between the buffer sheet 100 and battery components (such as single cell 20, housing (or support member) 30, etc.). It should be noted that as in the example shown in (b) of Figure 1 , regarding the clamping members 210 and 220, it is only necessary to be provided between the buffer sheet 100 and the battery components, and the structure is not limited to direct contact with the battery components.

[0054] The buffer sheet 100 is made of an elastomer. In addition, the elastomer preferably uses a material with a hardness value measured by a JIS K6253 type E durometer of 50 degrees to 90 degrees (more preferably 60 degrees to 80 degrees). Thereby, the buffer function can be appropriately exerted. More specifically, EPDM, silicone rubber, etc. can be used.

[0055] By assembling the buffer sheet 100 and the clamping members 210 and 220 to a frame (or a supporting member) 30 etc., if the positioning of the buffer sheet 100 and the clamping members 210 and 220 can be carried out, a structure for fixing the buffer sheet 100 and the clamping members 210 and 220 etc. is not required. However, in the case where positioning cannot be carried out, a structure for fixing the buffer sheet 100 to the clamping members 210 and 220 needs to be provided. For example, a structure in which the buffer sheet 100 is adhered to the clamping members 210 and 220 by double-sided tape can be adopted, or a structure in which the buffer sheet 100 and the clamping members 210 and 220 are positioned by accommodating them in a bag-shaped film etc. can be adopted by appropriate known techniques. In addition, in order to position the buffer sheet 100 and the battery component, a structure in which they are adhered by double-sided tape can also be adopted. Of course, a structure for positioning the buffer sheet 100, the clamping members 210 and 220 can also be provided on the battery component.

[0056] In order for the battery buffer structure 10 to have a heat insulation function, it is preferable that both the buffer sheet 100 and the clamping members 210 and 220 are made of materials having heat insulation properties. However, depending on the usage conditions etc., when a necessary heat insulation effect is obtained by making either the buffer sheet 100 or the clamping members 210 and 220 have a heat insulation function, the other component can also be made of a material without heat insulation properties. When making the buffer sheet 100 have a heat insulation function, as the material of the buffer sheet 100, an elastomer material with high heat insulation such as a flame-retardant rubber or a flame-retardant elastomer can be appropriately applied. When making the clamping members 210 and 220 have a heat insulation function, it can be composed of a thin non-combustible board etc. mainly composed of asbestos-free natural mineral magnesium silicate. When making the clamping members 210 and 220 have a heat insulation function, the clamping members 210 and 220 can be called heat insulation members. It should be noted that the clamping members 210 and 220 are preferably composed of sheet-shaped (thin plate-shaped) components so that the overall thickness of the battery buffer structure 10 does not become too thick. As shown in the figure, the clamping members 210 and 220 related to this embodiment are composed of sheet-shaped components.

[0057] The buffer sheet 100 has a plurality of protrusions 120a and 120b. These protrusions 120a and 120b are configured such that the inside is a cavity, and the space inside the cavity is configured to be open (unclosed) on the side opposite to the protruding direction of the protrusion. In other words, the buffer sheet 100 can also have a plurality of protrusions 120a and 120b with a hollow inside that are open on the opposite side of the protruding direction.

[0058] As Figure 2 shown, a plurality of protrusions 120a and 120b are provided on each of the two sides of the buffer sheet 100. In Figure 2In (a) of [], in order to easily understand the arrangement of the protrusions 120a and 120b, their outlines are shown in perspective and represented by dashed lines. As shown in the figure, the protrusions 120a provided on one surface of the buffer sheet 100 and the protrusions 120b provided on the other surface of the buffer sheet 100 are arranged alternately in a vertical and horizontal pattern. It is configured such that the height of the protrusion 120a is the same as the height of the protrusion 120b. Thus, the functions on both sides of the battery buffer structure 10 are the same, so there is no need to confirm the front and back sides during the installation operation of the battery buffer structure 10. It should be noted that in Figure 2 In the top view shown in (a) of [], only an example of the arrangement of the protrusions 120a and 120b is shown. Regarding the number and arrangement method of the protrusions 120a and 120b, they can of course be appropriately set according to the size of the buffer sheet 100 and the like. In addition, in the illustrated example, the protrusions 120a and 120b are arranged alternately parallel or perpendicular to the four side surfaces of the buffer sheet 100, but the protrusions 120a and 120b can also be configured to be arranged alternately at an angle with respect to the above four side surfaces.

[0059] Here, the protrusion 120a can be referred to as a protrusion with an internal hollow that protrudes toward the clamping member 210 and is open on the opposite side of the protruding direction. In addition, the protrusion 120a can also be referred to as a protrusion with an internal hollow that protrudes toward the opposite side of the clamping member 220 and is open on the side of the clamping member 220.

[0060] On the other hand, the protrusion 120b can be referred to as a protrusion with an internal hollow that protrudes toward the clamping member 220 and is open on the opposite side of the protruding direction. In addition, the protrusion 120b can also be referred to as a protrusion with an internal hollow that protrudes toward the opposite side of the clamping member 210 and is open on the side of the clamping member 210.

[0061] Refer to Figure 3 The dimensional relationships of the respective parts of the battery buffer structure 10 will be described. Figure 3 In (a) of [], H1 is the maximum thickness of the buffer sheet 100 in the protruding direction of the protrusion in a state where no external force is applied to the battery buffer structure 10. In Figure 3 In (b) of [], regarding the buffer sheet 100, the dimensions of the respective parts in a state where no external force is applied are shown. H is the maximum thickness of the buffer sheet 100 in the protruding direction of the protrusion, T1 is the wall thickness of the flat plate-like part in the buffer sheet 100, T2 is the wall thickness of the main body part in the protrusions 120a and 120b, T3 is the wall thickness of the frontmost part in the protrusions 120a and 120b, L is the interval between the frontmost parts of the adjacent protrusions 120a and 120b, and d is the inclination angle of the main body part in the protrusions 120a and 120b with respect to the flat plate-like part. These dimensions can be appropriately adjusted according to the use environment and the like. Regarding T1, T2, and T3, they can all be set to be the same, or they can be set to be different from each other.

[0062] For example, T1 can be set to about 0.1 mm to 10 mm. In addition, in order to fully exert the buffering function, it is preferable to satisfy H > 3×T (T1, T2, T3). It should be noted that the dimensions of the buffer sheet 100 in the longitudinal and transverse directions (the longitudinal and transverse directions when observed in the top view) can be the same as or slightly smaller than the dimensions of the single cell 20 in the longitudinal and transverse directions. In addition, T2 can be set to about 0.1 mm to 10 mm. Regarding the density of the protruding portions 120a and 120b, it can be set to 1 to 6 per cm 2 or so.

[0063] Moreover, in this embodiment, when the maximum thickness H1 of the buffer sheet 100 in the protruding direction of the protrusion becomes half in the state where the battery buffer structure 10 is compressed to a state where no external force is applied to the battery buffer structure 10, it is configured that the back side of the front end portion of the protrusion 120a does not contact the clamping member 220 and a space is maintained between the protrusion 120a and the clamping member 220. That is, as Figure 4 (a) shows, even when an external force is applied in the direction of arrow P to compress the battery buffer structure 10 such that the compression rate of the protrusion 120a is 50% (H2 = 0.5×H1), the back side of the front end portion of the protrusion 120a does not contact the clamping member 220. Thus, a space (for example, the region shown as A1 in the figure) is maintained between the protrusion 120a and the clamping member 220. The relationship between the protrusion 120b and the clamping member 210 is the same, and even when the compression rate of the protrusion 120b is 50%, a space (for example, the region shown as A2 in the figure) is maintained between the protrusion 120b and the clamping member 210.

[0064] An example of a specific example for maintaining a space on the back side of the protrusion even when the compression rate of the protrusion is 50% will be described. As the material of the buffer sheet 100, EPDM with a hardness of Duro A75, an elongation rate of 250%, and a tensile strength of 6.8 MPa was used. It should be noted that the material properties of the hardness are based on the JIS standard JIS K6253, the measurement condition is a Type A hardness tester, and the material properties of the elongation rate and the tensile strength are based on the JIS standard JIS K6251, and the measurement condition is an elongation speed of 500 mm / min. In addition, regarding the dimensions of each part, H = 3.3 mm, T1 = 0.8 mm, T2 = 0.6 mm, T3 = 1 mm, L = 3.5 mm, and d = 40° were set. The clamping member 210 is made of a thin non-combustible plate mainly composed of asbestos-free natural mineral magnesium silicate with a thickness of 1.2 mm and a thermal conductivity of 0.2 W / mK. Figure 4The chart in (b) shows the relationship between the compression ratio of the protrusions 120a and 120b in this specific example and the surface pressure between the protrusions 120a and 120b and the clamping members 210 and 220. The measured conditions for this chart are a temperature of 25°C and a compression speed of 0.1 mm / min. From this chart, it can be seen that even when the compression ratio exceeds 50%, there will be no sharp increase in surface pressure. Moreover, when the surface pressure rises sharply, it can be considered that the back side of the front end of the protrusion contacts the clamping member and the space disappears (almost disappears). From this, it can be known that assuming a flat material is used as the buffer sheet, even with a low compression ratio, the surface pressure will rise sharply. In addition, in a structure where a plurality of protrusions without a hollow part are provided on the flat buffer sheet, it can also be known that the surface pressure does not increase in the part without the protrusion, so the increase in the reaction force of the entire buffer sheet can be suppressed, but in the part where the protrusion contacts, the surface pressure rises sharply.

[0065] <Advantages of the battery buffer structure according to this embodiment>

[0066] According to the battery buffer structure 10 according to this embodiment, clamping members 210 and 220 are provided between the buffer sheet 100 and battery component parts (such as single cells 20 and frames 30). Therefore, the stress generated by the protrusions 120a and 120b of the buffer sheet 100 is dispersed by the clamping members 210 and 220. In this way, the clamping members 210 and 220 according to this embodiment have a stress dispersion function of dispersing the stress generated by the protrusions 120a and 120b. In addition, if the clamping members 210 and 220 have a certain degree of rigidity, they have a stress dispersion function. Thereby, stress concentration of the protrusions 120a and 120b on the battery component parts can be suppressed. In addition, the protrusions 120a and 120b have a structure with a hollow interior and an open opposite side in the protruding direction. Therefore, even when compressed, a sharp increase in the reaction force can be suppressed. Thereby, the buffer function can be improved. Therefore, the load of stress on the single cell 20 and the like associated with the expansion and contraction of the single cell 20 can be suppressed, and in addition, the vibration transmitted to the battery 1 can be absorbed. Thereby, the quality of the single cell 20 can be stably maintained and the life of the battery 1 can be extended.

[0067] In addition, when the clamping members 210 and 220 have a heat insulation function, even if the temperature of any single cell 20 rises sharply for some reason, the spread of heat can be suppressed.

[0068] In addition, in this embodiment, even when the battery buffer structure 10 is compressed until the maximum thickness of the buffer sheet 100 in the protruding direction of the protrusion becomes half, a space can be maintained between the protrusion and the clamping member. Therefore, a sharp increase in the rebounding force of the battery buffer structure 10 can be suppressed. In addition, there is also an effect of maintaining a heat insulation function through the air in the space.

[0069] Moreover, the protrusions 120a and 120b according to the present embodiment are configured such that the area surrounded by the outer shape of the cross section perpendicular to their protruding directions gradually narrows toward the front end in the protruding direction. That is, the outer shapes of the protrusions 120a and 120b according to the present embodiment are substantially frustum cone shapes in which the front end of a cone is formed by a curved surface. Therefore, it is configured such that when the protrusions 120a and 120b are cut by a plane perpendicular to their protruding directions, the outer shape is circular, and the area of the circle gradually narrows toward the front end in the protruding direction.

[0070] With such a structure, it is possible to increase the volume inside the hollow portions of the protrusions 120a and 120b and suppress a sharp increase in the elastic restoring force, and it is easy to maintain a space even when the buffer sheet 100 is compressed. At the same time, it is possible to reduce the area of the front ends of the protrusions 120a and 120b. Therefore, the contact areas of the protrusions 120a and 120b with the single battery 20, the frame body 30, etc. become smaller, and heat transfer can be suppressed.

[0071] Here, regarding the outer shape of the protrusion, it is not limited to the substantially frustum cone shape described in Embodiment 1, and various shapes can be adopted. In Embodiment 2, the case where the outer shape of the protrusion is a hemispherical shape will be described.

[0072] (Embodiment 2)

[0073] Figure 5 Embodiment 2 of the present invention is shown. In the present embodiment, the structure in the case where the outer shape of the protrusion is a hemispherical shape will be described. Other structures and operations are the same as those in Embodiment 1, so the same reference numerals are assigned to the same structural parts, and their descriptions are appropriately omitted.

[0074] Figure 5 It is an explanatory view of the battery buffer structure according to Embodiment 2 of the present invention. (a) is a top view of the battery buffer structure, (b) is a side view of the buffer sheet, and (c) is a graph showing the relationship between the compression ratio and the surface pressure.

[0075] The batteries to which the battery buffer structure 10X according to the present embodiment can be applied are the same as those in Embodiment 1, so their descriptions are omitted. The battery buffer structure 10X is also composed of a buffer sheet 100X and clamping members 210 and 220 as in Embodiment 1. Regarding the clamping members 210 and 220, as described in Embodiment 1. In addition, in Figure 5 (a), only the clamping member 210 is shown. Regarding the necessity of the structure for fixing the buffer sheet 100X to the clamping members 210 and 220 and the structure in the case of fixing, they are also as described in Embodiment 1. Regarding the structure in the case where the battery buffer structure 10X has a heat insulation function, it is also as described in Embodiment 1.

[0076] The buffer sheet 100X involved in this embodiment includes a plurality of protrusions 121a and 121b. These protrusions 121a and 121b are also configured to have a cavity inside, and the space inside the cavity is configured to open (be open) on the side opposite to the protruding direction of the protrusion, just as in Embodiment 1. In other words, the buffer sheet 100 can also be said to include a plurality of protrusions 121a and 121b that are internally hollow and open on the opposite side of the protruding direction. In this embodiment, only the outer shape of the protrusions 121a and 121b is different from that in Embodiment 1 in that it is hemispherical. In addition, in Figure 5 In (b) of, the outlines of the hollow parts of the leftmost protrusion 121a and the second protrusion 121b from the left are shown by dotted lines. As Figure 5 As shown in (b) of, a plurality of protrusions 121a and 121b are provided on each of the two sides of the buffer sheet 100X. In Figure 5 In (a) of, in order to easily understand the arrangement of the protrusions 121a and 121b, their outlines are shown in perspective and by dotted lines. As shown in the figure, the protrusions 121a provided on one side of the buffer sheet 100X and the protrusions 121b provided on the other side of the buffer sheet 100X are alternately arranged vertically and horizontally. The height of the protrusion 121a and the height of the protrusion 121b are configured to be the same as in Embodiment 1. In addition, in Figure 5 In the top view shown in (a) of, only an example of the arrangement of the protrusions 121a and 121b is shown. Of course, the number and arrangement method of the protrusions 121a and 121b can be appropriately set according to the size of the buffer sheet 100X, etc. In the illustrated example, the protrusions 121a and 121b are alternately arranged parallel or perpendicular to the four side surfaces of the buffer sheet 100, but the protrusions 121a and 121b can also be configured to be alternately arranged obliquely with respect to the above four side surfaces.

[0077] Here, the protrusion 121a can be called a protrusion that protrudes toward the clamping member 210 and is internally hollow and open on the opposite side of the protruding direction. In addition, this protrusion 121a can also be called a protrusion that protrudes toward the opposite side of the clamping member 220 and is open on the side of the clamping member 220 and is internally hollow.

[0078] On the other hand, the protrusion 121b can be called a protrusion that protrudes toward the clamping member 220 and is internally hollow and open on the opposite side of the protruding direction. In addition, this protrusion 121b can also be called a protrusion that protrudes toward the opposite side of the clamping member 210 and is open on the side of the clamping member 210 and is internally hollow.

[0079] Refer to Figure 5 To describe the dimensional relationship of each part of the battery buffer structure 10. In Figure 5In (b) thereof, regarding the buffer sheet 100X, the dimensions of each part in the state where no external force is applied are shown. H is the maximum thickness of the buffer sheet 100X in the protruding direction of the protruding part, T1 is the wall thickness of the flat part in the buffer sheet 100X, and L is the interval between the front end parts of the adjacent protruding parts 121a and 121b. These dimensions can be appropriately adjusted according to the use environment and the like. For example, T1 can be set to about 0.1 mm to 10 mm. In addition, in order to fully exert the buffering function, it is preferable to satisfy H > 3 × T1. It should be noted that regarding the horizontal and vertical dimensions (horizontal and vertical dimensions when observed in a top view) of the buffer sheet 100X, they can be the same as or slightly smaller than the horizontal and vertical dimensions of the single cell 20. Regarding the density of the protruding parts 121a and 121b, it can be set to 1 to 6 pieces / cm 2 or so.

[0080] Moreover, in the present embodiment, it is also configured such that when the battery buffer structure 10X is compressed until the maximum thickness of the buffer sheet 100X in the protruding direction of the protruding part in the state where no external force is applied to the battery buffer structure 10X becomes half, the back side of the front end part of the protruding part 121a does not contact the clamping member 220 and a space is maintained between the protruding part 121a and the clamping member 220.

[0081] An example of a specific example for maintaining a space on the back side of the protruding part even when the compression rate of the protruding part is 50% will be described. As the material of the buffer sheet 100X, EPDM with a hardness of Duro A75, an elongation rate of 250%, and a tensile strength of 6.8 MPa was adopted. The measurement conditions of each material property are the same as those in Example 1. In addition, regarding the dimensions of each part, H = 3.5 mm, T1 = 0.5 mm, and L = 3.5 mm were set. The clamping member 210 was made of a thin non-combustible plate mainly composed of asbestos-free natural mineral magnesium silicate with a thickness of 1.2 mm and a thermal conductivity of 0.2 W / mK. Figure 5 (c) shows a graph representing the relationship between the compression rate of the protruding parts 121a and 121b and the surface pressure between the protruding parts 121a and 121b and the clamping members 210 and 220 in this specific example. This graph was obtained through 3D non-linear structural analysis. As the analysis conditions, the analysis element was set to a hexahedron first-order element, the temperature was set to room temperature, the material of the buffer sheet was set to EPDM, and the material of the heat insulation member was set to a non-combustible plate. From this graph, it can be seen that, similarly to Example 1, even when the compression rate exceeds 50%, there is no sharp increase in the surface pressure.

[0082] In the battery buffer structure 10X according to the present embodiment configured as described above, the same effects as those in the above-described Example 1 can also be obtained.

[0083] (Other)

[0084] Regarding the outer shape of the protruding portion, a structure other than the substantially frustum cone shape described in Embodiment 1 and the hemispherical shape described in Embodiment 2 can be adopted. That is, the protruding portion only needs to be configured such that the area surrounded by the cross-sectional outer shape perpendicular to its protruding direction gradually narrows toward the front end in the protruding direction. For example, as shown in (a) and (b) of Figure 6 , a protruding portion 122 in which the front end of a quadrangular pyramid is formed by a curved surface can also be adopted. In addition, Figure 6 , (a) of Figure 6 is a plan view of the protruding portion 122, and (b) of this figure is a view observed from the side. Of course, it is not limited to a quadrangular pyramid, and a triangular pyramid, a pentagonal pyramid, etc. in which the front end of a multi-pyramid is set to a curved surface shape can also be adopted. In addition, as shown in (c), (d), and (e) of Figure 6 , a protruding portion 123 in the shape of cutting a cylinder in half can also be adopted. Figure 6 , (c) of Figure 6 is a plan view of the protruding portion 123, Figure 6 , (d) of

[0085] is a view of observing the protruding portion 123 along the P1 direction in (c) of Figure 6 , and (e) of Figure 6 is a view of observing the protruding portion 123 along the P2 direction. Of course, the interiors of the protruding portions 122 and 123 are hollow.

[0085] In the above embodiments, a structure in which protruding portions are provided on both sides of the buffer sheet is shown. However, the present invention also includes a structure in which protruding portions are provided only on one side. In this case, a structure in which a clamping member is disposed only on the side of the surface where the protruding portion is provided can be adopted. Thereby, the clamping member exhibits a stress dispersion function of dispersing the stress of the protruding portion. In addition, a structure in which a clamping member is disposed only on the opposite side of the surface where the protruding portion is provided can also be adopted. Thereby, the escape of air in the hollow portion can be suppressed, and thus even when the compression ratio of the protruding portion is 50%, it is easy to maintain a space on the back side of the protruding portion. Of course, as in each embodiment, it is preferable to provide clamping members on both sides respectively.

[0086] In addition, in the above embodiments, a structure in which protruding portions having the same size and shape are provided on both sides of the buffer sheet is shown. However, when protruding portions are provided on both sides of the buffer sheet, it is not necessarily required to make the protruding portions on both sides have the same size and shape. That is, protruding portions having the same shape can be provided on both sides, and the height of the protruding portion provided on one surface can be made different from that of the protruding portion provided on the other surface. In addition, for example, the protruding portion shown in Embodiment 1 can be adopted on one surface, and the protruding portion shown in Embodiment 2 can be provided on the other surface. In this case, the height of the protruding portions can be the same or different.

[0087] In addition, in the above-described embodiment, a case where the buffer sheet and the clamping member (heat insulation member) are formed of different members is shown. However, the battery buffer structure may also be formed of a member integrally having a portion corresponding to the buffer sheet and a portion corresponding to the clamping member. That is, the buffer sheet and the clamping member (heat insulation member) may be formed integrally.

[0088] Description of Reference Numerals

[0089] 1: Battery

[0090] 10, 10X: Battery buffer structure

[0091] 20: Single cell

[0092] 30: Frame (support member)

[0093] 100, 100X: Buffer sheet

[0094] 120a, 120b, 121a, 121b, 122, 123: Protrusion

[0095] 210, 220: Clamping member.

Claims

1. A buffer structure for a battery, comprising: A buffer sheet; And A heat insulation member disposed between the buffer sheet and a battery component, The buffer structure for a battery is characterized in that The buffer sheet includes a protruding portion protruding toward the heat insulation member.

2. A buffer structure for a battery, comprising a buffer sheet and a clamping member, The buffer structure for a battery is characterized in that The buffer sheet includes a protruding portion protruding toward the clamping member, The clamping member has a stress dispersion function for dispersing the stress generated by the protruding portion.

3. A buffer structure for a battery, comprising a buffer sheet and a clamping member, The buffer structure for a battery is characterized in that The buffer sheet includes a protruding portion protruding toward the opposite side of the clamping member, When the maximum thickness of the buffer sheet in the protruding direction of the protruding portion in a state where the buffer structure for a battery is compressed to a state where no external force is applied to the buffer structure for a battery becomes half, the back side of the front end portion of the protruding portion does not contact the clamping member and a space is maintained between the protruding portion and the clamping member.

4. The buffer structure for a battery according to claim 1, 2 or 3, characterized in that A plurality of the protruding portions are respectively provided on both surfaces of the buffer sheet.

5. The buffer structure for a battery according to claim 4, characterized in that The protruding portions provided on one surface of the buffer sheet and the protruding portions provided on the other surface of the buffer sheet are alternately arranged vertically and horizontally.

6. The buffer structure for a battery according to claim 4, characterized in that The height of the protruding portions provided on one surface of the buffer sheet is the same as the height of the protruding portions provided on the other surface of the buffer sheet.

7. The buffer structure for a battery according to claim 4, characterized in that The maximum thickness of the buffer sheet in the protruding direction of the protruding portion is thicker than three times the wall thickness of the buffer sheet.

8. The buffer structure for a battery according to claim 1, 2 or 3, characterized in that The area surrounded by the outer shape of the cross section perpendicular to the protruding direction of the protruding portion gradually narrows toward the front end in the protruding direction.

9. The buffer structure for a battery according to claim 1, characterized in that The buffer sheet and the heat insulation member are integrated.

10. The buffer structure for a battery according to claim 2 or 3, characterized in that The buffer sheet and the clamping member are integrated.

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