Buffer spacer for battery module

Abstract

To provide a buffer spacer for a battery module which has a cooling function and a gap variation absorption function accompanying deformation during normal operation, and can suppress thermal influence on other battery cells during abnormal heat generation.SOLUTION: A cushioning spacer 101 includes a spacer body 110 made of a leaf spring and formed with at least two folds. The spacer body 110 includes a first end plate 111 that is in surface contact with a first battery cell 2a, a second end plate 112 that is in surface contact with a second battery cell 2b or support members 3a and 3b, at least one heat shield intermediate plate 113 that faces the rear surface of a first contact surface 111a of the first end plate 111 via a fluid flow layer 110a, faces the rear surface of a second contact surface 112a of a second end plate 112 with a distance therebetween, and shields radiant heat from the first battery cell 2a, and a plurality of elastic portions 114 and 115 that constitute the fold.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a buffer spacer for a battery module. [Background technology]

[0002] In a battery module consisting of multiple stacked battery cells, the battery cells expand when charged and contract when discharged. It is known to place spacers between adjacent battery cells to absorb deformation caused by the expansion and contraction of the battery cells. Furthermore, the battery cells generate heat and therefore need to be cooled.

[0003] Patent Document 1 describes a spacer that includes a pair of pressure plates and a C-shaped spring member disposed between the pair of pressure plates. The elasticity of the C-shaped spring member can absorb deformation of the battery cells and apply pressure to the battery cells. Furthermore, the battery cells can be cooled by circulating a cooling fluid between the pair of pressure plates.

[0004] Patent Document 2 describes placing a thermally conductive sheet made of a rubber-like elastic material between the battery cell and the cooling member, and also between adjacent battery cells, which cools the battery cell and absorbs deformation of the battery cell.

[0005] Patent Document 3 describes placing a spacer between adjacent battery cells through which a cooling fluid flows and providing a heat shield on the surface of the battery cells, which cools the battery cells and absorbs deformation of the battery cells. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-170140 [Patent Document 2] Japanese Patent Application Publication No. 2019-079780 [Patent Document 3] Japanese Patent Publication No. 2021-005486 Summary of the Invention [Problem to be solved by the invention]

[0007] During normal battery cell operation, spacers are required to cool heated battery cells and absorb gap variations caused by expansion and contraction of the battery cells. Furthermore, it is important to prevent abnormal heat generation in one battery cell from affecting other battery cells. Conventional spacers are effective enough during normal battery cell operation. However, there is room for improvement in the case of abnormal heat generation in a battery cell.

[0008] The present invention has been made in view of the above background, and aims to provide a buffer spacer for a battery module that has a cooling function and a function to absorb gap variations caused by deformation during normal battery cell operation, and that can suppress thermal effects on other battery cells when a battery cell generates abnormal heat. [Means for solving the problem]

[0009] One aspect of the present invention is a buffer spacer for a battery module, the buffer spacer being disposed in a gap between a first battery cell and a second battery cell or in a gap between the first battery cell and a support member, the buffer spacer absorbing gap fluctuations caused by expansion and contraction of at least the first battery cell; a spacer body formed of a leaf spring and having at least two folded portions; The spacer body includes: a first end plate having a first contact surface that is in surface contact with the first battery cell; a second end plate having a second contact surface that is in surface contact with the second battery cell or the support member; at least one heat-shielding intermediate plate that faces a rear surface of the first contact surface of the first end plate via a fluid flow layer and faces a rear surface of the second contact surface of the second end plate at a distance, and that blocks radiant heat from the first battery cell; A plurality of elastic portions that form the folded portion; The buffer spacer for a battery module includes: [Effects of the Invention]

[0010] The spacer body of the buffer spacer is formed into a shape with folded portions by a leaf spring, and has elastic portions that constitute the folded portions. Elastic deformation of the elastic portions can absorb gap fluctuations caused by expansion and contraction of the first battery cell. Furthermore, the spacer body includes a first end plate that makes surface contact with the first battery cell, a second end plate that makes surface contact with the second battery cell or the support member, and at least one heat-shielding intermediate plate located between the first end plate and the second end plate. In other words, the spacer body has at least two folded portions and includes at least three plate members. A fluid flow layer is formed between the first end plate and the heat-shielding intermediate plate. Therefore, fluid flows through the fluid flow layer, making it possible to cool the first battery cell. In this way, the buffer spacer has a cooling function and a function to absorb gap fluctuations caused by deformation during normal battery cell operation.

[0011] Furthermore, if the first battery cell generates abnormal heat, the radiant heat from the first battery cell is cooled by the fluid in the fluid flow layer as it passes through the fluid flow layer between the first end plate and the heat-shielding intermediate plate. However, the radiant heat from the first battery cell may pass through the fluid flow layer and reach the heat-shielding intermediate plate. Here, the heat-shielding intermediate plate can block the radiant heat from the first battery cell. Therefore, the radiant heat from the first battery cell can be blocked by the heat-shielding intermediate plate after passing through the fluid flow layer, and can be prevented from being transmitted downstream of the heat-shielding intermediate plate in the direction of radiant heat transmission. Therefore, when the first battery cell generates abnormal heat, the buffer spacer can suppress heat transfer, thereby preventing thermal effects on other battery cells, etc. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 10 is a diagram showing a battery module to which a buffer spacer is applied, showing a state in which the battery cells are not expanded. [Figure 2] 2 is a diagram showing an expansion state of a battery cell during charging in the battery module shown in FIG. 1. FIG. [Figure 3] FIG. 2 is an enlarged schematic view of the buffer spacer of the first embodiment. [Figure 4] FIG. 10 is an enlarged schematic view of a buffer spacer according to a second embodiment. [Figure 5] FIG. 10 is an enlarged schematic view of a buffer spacer according to a third embodiment. [Figure 6] FIG. 10 is an enlarged schematic view of a buffer spacer according to a fourth embodiment. [Figure 7] FIG. 10 is an enlarged schematic view of a buffer spacer according to a fifth embodiment. [Figure 8] FIG. 8 is a view of the buffer spacer shown in FIG. 7 as seen from the right. [Figure 9] FIG. 13 is an enlarged schematic view of a buffer spacer according to a modified embodiment of the fifth embodiment. [Figure 10] FIG. 13 is an enlarged schematic view of a buffer spacer according to a sixth embodiment. [Figure 11] 11 is a cross-sectional view taken along the line XX in FIG. [Figure 12] FIG. 20 is an enlarged schematic view of a buffer spacer according to a modified embodiment of the sixth embodiment. [Figure 13] FIG. 13 is an enlarged schematic view of a buffer spacer according to a seventh embodiment. [Figure 14] 12 is a partial cross-sectional view of FIG. 13 taken along the line XII-XII. [Figure 15] FIG. 13 is an enlarged schematic view of a buffer spacer according to an eighth embodiment. [Figure 16] FIG. 13 is an enlarged schematic view of a buffer spacer according to a ninth embodiment. [Figure 17] FIG. 20 is an enlarged schematic view of the buffer spacer of the tenth embodiment. [Figure 18] FIG. 20 is an enlarged schematic view of the buffer spacer of the eleventh embodiment. [Figure 19] FIG. 22 is an enlarged schematic view of the buffer spacer of the twelfth embodiment. [Figure 20] FIG. 22 is an enlarged schematic view of the buffer spacer of the thirteenth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] (Embodiment) The overall configuration of a battery module 1 will be described with reference to Figures 1 and 2. Examples of the battery module 1 include a storage battery such as a lithium-ion secondary battery for automobiles or homes, or a cell stack for a fuel cell system. As shown in Figure 1, the battery module 1 includes a plurality of stacked battery cells 2, a support member 3, and a plurality of buffer spacers 4.

[0014] The battery cells 2 are formed, for example, in a flat rectangular parallelepiped shape. The individual battery cells 2 are arranged in the normal direction of the flat surface. For example, the battery cells 2 are arranged horizontally. The battery cells 2 include a housing 21 formed in the shape of a flat rectangular parallelepiped box and an electrode assembly 22 wound inside the housing 21. The housing 21 is formed, for example, from a metal such as aluminum or a hard resin with good heat dissipation and heat resistance. The electrode assembly 22 includes a positive electrode, a negative electrode, and a separator sandwiched between the positive and negative electrodes, and is wound in a flat shape.

[0015] As shown in FIG. 2, the electrode body 22 generates heat as it is charged and expands primarily in the direction normal to its flat surface. The amount of expansion of the electrode body 22 decreases as it is discharged. Therefore, the casing 21 that houses the electrode body 22 expands in the direction normal to its flat surface during charging. In particular, because the casing 21 is formed in the shape of a rectangular flat box, the flat surface of the casing 21 expands and deforms in a curved convex shape. When the battery cell 2 is discharged, the amount of expansion of the electrode body 22 decreases, and the flat surface of the casing 21 ideally returns to a flat shape. In this way, the casing 21 of the battery cell 2 repeatedly expands and contracts as it is charged and discharged.

[0016] The support members 3 support the multiple battery cells 2 from both ends in the stacking direction of the battery cells 2. In other words, when each battery cell 2 expands due to charging, the support members 3 apply a reaction force to each battery cell 2, thereby returning the battery cell 2 to its normal state (non-expanded state).

[0017] The support member 3 includes, for example, a first support member 3a, a second support member 3b, and a connecting member 3c. However, the configuration of the support member 3 is not limited to this example, and various forms such as a box-shaped housing can be applied. The support member 3 may be made of any material that can exert a binding force, such as hard resin or metal.

[0018] The support member 4 may be, for example, a housing that forms a closed space. The housing constitutes the outer frame of the battery module 1. In this case, the internal space of the housing serving as the support member 4 is partitioned on all sides from the outside of the housing.

[0019] The first support member 3a is formed in an L-shape and includes a base portion on which the horizontally arranged multiple battery cells 2 are placed, and a portion that supports a first end side (right side in FIG. 1) in the arrangement direction of the multiple battery cells 2. The second support member 3b is formed, for example, in a flat plate shape and is arranged on a second end side (left side in FIG. 1) opposite the first end in the arrangement direction of the multiple battery cells 2. Therefore, the arranged multiple battery cells 2 are sandwiched between the first support member 3a and the second support member 3b in the arrangement direction. The connecting member 3c connects the first support member 3a and the second support member 3b.

[0020] In the arrangement direction of the multiple battery cells 2, the buffer spacers 4 are arranged in the gaps between adjacent battery cells 2, the gaps between the battery cells 2 and the first support member 3a, and the gaps between the battery cells 2 and the second support member 3b. The buffer spacers 4 are arranged in contact with both members that form the gaps. While FIG. 1 shows an example in which the buffer spacers 4 are arranged between all adjacent battery cells 2, it is also possible to arrange for them not to be arranged between some of the adjacent battery cells 2.

[0021] The buffer spacer 4 is made of an elastic material. The buffer spacer 4 absorbs gap variations caused by the expansion and contraction of the battery cells 2 through its own elastic deformation. As shown in FIG. 1, when the amount of expansion of the battery cells 2 is small, the buffer spacer 4 elastically supports the battery cells 2 by contacting them. As shown in FIG. 2, when the battery cells 2 expand due to charging, the buffer spacer 4 elastically supports the battery cells 2, and when the amount of expansion decreases due to discharging, the buffer spacer 4 applies a pressing force to the battery cells 2. In this way, the buffer spacer 4 functions to absorb gap variations caused by deformation of the battery cells 2 during normal battery cell operation.

[0022] Furthermore, the buffer spacer 4 has a fluid flow layer 4a (hereinafter referred to as the "internal space layer 4a") through which a cooling fluid can flow so that the area where the buffer spacer 4 is arranged, i.e., the area occupied by the buffer spacer 4, can provide a cooling function. In other words, the buffer spacer 4 can flow a cooling fluid in the area occupied by the buffer spacer 4. Therefore, during normal operation of the battery cell 2, the buffer spacer 4 provides a cooling function in addition to absorbing gap fluctuations.

[0023] Furthermore, when the buffer spacer 4 is disposed in each gap, a fluid flow space 5 (hereinafter referred to as the "surrounding space 5") is formed around the buffer spacer 4. In particular, the surrounding space 5 is formed around the entire outer periphery of the buffer spacer 4, with the direction in which the gap is formed as the central axis. When multiple battery cells 2 are arranged horizontally, the surrounding space 5 is formed in all directions, above, below, left, and right, around the buffer spacer 4 when viewed from the arrangement direction of the battery cells 2. This surrounding space 5 is preferably formed around the entire periphery of the buffer spacer 4, but it is sufficient that it is formed at least in the upper and side regions. For example, if the support member 3 is a housing that forms the outer frame of the battery module 1, the surrounding space 5 forms part of the internal space of the housing.

[0024] As described above, an internal space layer 4a is formed in the area occupied by the buffer spacer 4. Furthermore, the buffer spacer 4 is formed so that the internal space layer 4a in the area occupied by the buffer spacer 4 and the surrounding space 5 located around the buffer spacer 4 can communicate with each other.

[0025] Therefore, when the fluid present in the internal space layer 4a occupied by the buffer spacer 4 is heated, the heated fluid flows out into the surrounding space 5, and conversely, the cold fluid present in the surrounding space 5 of the buffer spacer 4 flows into the internal space layer 4a occupied by the buffer spacer 4. In other words, convection can be generated between the internal space layer 4a and the surrounding space 5. This convection can lower the temperature of the fluid in the internal space layer 4a occupied by the buffer spacer 4. In this way, the buffer spacer 4, working in cooperation with the surrounding space 5, exhibits a high cooling function.

[0026] The buffer spacer 4 also functions to suppress the thermal impact on the surrounding area when a battery cell 2 generates abnormal heat. When a battery cell 2 generates abnormal heat, it can reach extremely high temperatures. In this case, it is important to prevent the surrounding area of ​​the abnormally heated battery cell 2, particularly other battery cells 2, from being thermally affected. Therefore, when a battery cell 2 generates abnormal heat, the buffer spacer 4 reduces the heat transferred to the other battery cells 2, thereby suppressing the thermal impact on the other battery cells 2.

[0027] (Embodiment 1) As an example of the buffer spacer 4 shown in Fig. 1, a buffer spacer 101 of embodiment 1 will be described with reference to Fig. 3. In Fig. 3, the thickness and gap of the buffer spacer 101 are exaggerated, and the actual thickness and gap are small.

[0028] The buffer spacer 101 is disposed in the gap between the first battery cell 2 a and the second battery cell 2 b, and absorbs gap fluctuations that occur due to expansion and contraction of the first battery cell 2 a and the second battery cell 2 b. The buffer spacer 101 includes a spacer body 110.

[0029] The spacer body 110 is formed of a leaf spring and has two folded portions. In this embodiment, the spacer body 110 is formed in a zigzag shape. In this embodiment, the spacer body 110 has two folded portions, but it may have three or more folded portions. The spacer body 110 is preferably made of a material that has a high elastic modulus and excellent formability, such as press working, such as metal, for example, iron, aluminum, nickel, chromium, titanium, or an alloy containing these as its main component.

[0030] The spacer body 110 includes a first end plate 111, a second end plate 112, a heat-shielding intermediate plate 113, and a plurality of elastic portions 114, 115. The spacer body 110 is formed to have the same width over its entire length from the first end plate 111 to the second end plate 112. In other words, the first end plate 111, the second end plate 112, the heat-shielding intermediate plate 113, and the plurality of elastic portions 114, 115 are all formed to have the same width.

[0031] The first end plate 111 is located at one end of the spacer body 110 in the flat thickness direction and has a first contact surface 111a that makes surface contact with the flat surface of the first battery cell 2a. The first end plate 111 is formed as a planar plate. The first contact surface 111a may be in contact with the first battery cell 2a without being bonded, or may be bonded. Therefore, when the first battery cell 2a generates heat, the heat from the first battery cell 2a is transferred to the first end plate 111. Note that, while the first end plate 111 is formed as a planar plate over its entire length, a portion of the first end plate 111 that corresponds to the longitudinal end of the spacer body 110 (the upper end portion in FIG. 3 ) may be bent toward the inside of the flat thickness of the spacer body 110 (the left side in FIG. 3 ).

[0032] The second end plate 112 is located at the other end of the spacer body 110 in the flat thickness direction and has a second contact surface 112a that makes surface contact with the flat surface of the second battery cell 2b. The second end plate 112 is formed as a planar plate. The second contact surface 112a may be in contact with the second battery cell 2b without being bonded, or may be bonded. Note that, while the second end plate 112 is formed flat over its entire length, it may also be formed by bending a portion corresponding to a longitudinal end of the spacer body 110 (the lower end in FIG. 3 ) toward the inside of the flat thickness of the spacer body 110 (to the right in FIG. 3 ).

[0033] The heat shielding intermediate plate 113 is disposed at a distance from the rear surface of the first contact surface 111a of the first end plate 111. The opposing space between the heat shielding intermediate plate 113 and the first end plate 111 forms a fluid circulation layer 110a, which serves as the internal space layer 4a in FIG. 1. In other words, the heat shielding intermediate plate 113 is disposed opposite the first end plate 111 with the fluid circulation layer 110a interposed therebetween. Therefore, the fluid circulation layer 110a exerts the effect of cooling the radiant heat of the first battery cell 2a.

[0034] Furthermore, the heat shielding intermediate plate 113 is disposed at a distance from the rear surface of the second contact surface 112a of the second end plate 112. The opposing space between the heat shielding intermediate plate 113 and the second end plate 112 forms a fluid circulation layer 110b, which serves as the internal space layer 4a in FIG. 1. In other words, the heat shielding intermediate plate 113 is disposed opposite the second end plate 112 with the fluid circulation layer 110b interposed therebetween. Therefore, the fluid circulation layer 110b exerts the effect of cooling the radiant heat of the second battery cell 2b.

[0035] The heat-shielding intermediate plate 113 is disposed opposite most of the surface of the flat surface of the first battery cell 2a, including at least the central portion, and blocks radiant heat from the first battery cell 2a. Therefore, the radiant heat from the first battery cell 2a is cooled by the fluid flow layer 110a and then transferred to the heat-shielding intermediate plate 113, but the amount of heat transferred from the heat-shielding intermediate plate 113 to the opposite surface is reduced. In particular, the heat-shielding intermediate plate 113 is formed in a plate shape without holes. Therefore, the heat-shielding intermediate plate 113 does not have any portions through which radiant heat from the first battery cell 2a passes directly. Therefore, the heat-shielding intermediate plate 113 exhibits a high heat-shielding effect.

[0036] Furthermore, the heat shielding intermediate plate 113 is disposed opposite most of the surface of the flat surface of the second battery cell 2b, including at least the central portion, and blocks radiant heat from the second battery cell 2b. Therefore, the radiant heat from the second battery cell 2b is cooled by the fluid flow layer 110b and then transferred to the heat shielding intermediate plate 113, but the amount of heat transferred from the heat shielding intermediate plate 113 to the opposite surface is reduced. In particular, as described above, the heat shielding intermediate plate 113 is formed in a plate shape without holes. Therefore, the heat shielding intermediate plate 113 does not have any portions through which radiant heat from the second battery cell 2b directly passes. Therefore, the heat shielding intermediate plate 113 exhibits a high heat shielding effect.

[0037] In this embodiment, the heat shielding intermediate plate 113 is a flat plate parallel to the first end plate 111 and the second end plate 112. However, the heat shielding intermediate plate 113 may also be a flat plate inclined with respect to the first end plate 111 and the second end plate 112. However, by arranging the heat shielding intermediate plate 113 parallel to the first end plate 111 and the second end plate 112, the thickness of the fluid circulation layers 110a, 110b (the thickness in the normal direction of the heat shielding intermediate plate 113) can be made approximately the same over the entire range. In other words, the cooling effect of the fluid circulation layers 110a, 110b can be exerted without any variation in location.

[0038] The multiple elastic portions 114, 115 form the folded portions of the leaf spring that forms the spacer body 110. In this embodiment, the multiple elastic portions 114, 115 form zigzag folded portions. The multiple elastic portions 114, 115 elastically deform when the gap between the first battery cell 2a and the second battery cell 2b changes due to expansion and contraction of the first battery cell 2a and the second battery cell 2b. The elastic deformation of the multiple elastic portions 114, 115 allows the first end plate 111 to press against the first battery cell 2a and the second end plate 112 to press against the second battery cell 2b. The multiple elastic portions 114, 115 are formed in a bent shape without holes. The lack of holes in the elastic portions 114, 115 allows them to exert high elastic force.

[0039] The elastic portion 114 connects an end portion (the lower end in FIG. 3 ) of the first end plate 111 and one end (the lower end in FIG. 3 ) of the heat shielding intermediate plate 113. The elastic portion 114 is a plate bent into a U-shape or a V-shape with both ends separated. This allows the heat shielding intermediate plate 113 to be positioned parallel to the first end plate 111. However, the elastic portion 114 can also be a plate bent into a U-shape with both ends touching, in which case the heat shielding intermediate plate 113 may be positioned, for example, at an angle relative to the first end plate 111.

[0040] As described above, the first end plate 111 and the heat shielding intermediate plate 113 are connected only by the elastic portion 114. In other words, there is a gap between the first end plate 111 and the heat shielding intermediate plate 113 at the peripheral portion other than the portion where the elastic portion 114 is present. Therefore, the fluid circulation layer 110a, which is the opposing space between the heat shielding intermediate plate 113 and the first end plate 111, can communicate with the surrounding space 5 (shown in FIG. 1 ) around the buffer spacer 101. In other words, convection can be generated between the fluid circulation layer 110a and the surrounding space 5.

[0041] The elastic portion 115 connects one end of the second end plate 112 (the upper end in FIG. 3 ) to the other end of the heat shielding intermediate plate 113 (the upper end in FIG. 3 ). The elastic portion 115 is a plate bent into a U-shape or a V-shape with both ends spaced apart. This allows the heat shielding intermediate plate 113 to be positioned parallel to the second end plate 112. However, the elastic portion 115 can also be a plate bent into a U-shape with both ends touching, in which case the heat shielding intermediate plate 113 may be positioned at an angle relative to the second end plate 112, for example.

[0042] As described above, the second end plate 112 and the heat shielding intermediate plate 113 are connected only by the elastic portion 115. In other words, there is a gap between the second end plate 112 and the heat shielding intermediate plate 113 at the peripheral portion other than the portion where the elastic portion 115 is present. Therefore, the fluid circulation layer 110b, which is the opposing space between the heat shielding intermediate plate 113 and the second end plate 112, can communicate with the surrounding space 5 (shown in FIG. 1 ) around the buffer spacer 101. In other words, convection can be generated between the fluid circulation layer 110b and the surrounding space 5.

[0043] The effect of including the spacer body 110 in the buffer spacer 101 is explained below. The spacer body 110 is formed into a zigzag shape using a leaf spring, and has elastic portions 114 and 115 that form folded sections. The elastic deformation of the elastic portions 114 and 115 absorbs gap variations that accompany the expansion and contraction of the first battery cell 2a and the second battery cell 2b.

[0044] Furthermore, the spacer body 110 includes a first end plate that is in surface contact with the first battery cell 2a, a second end plate 112 that is in surface contact with the second battery cell 2b, and a heat-shielding intermediate plate 113 that is located between the first end plate 111 and the second end plate 112. In other words, the spacer body 110 includes three plate members formed by zigzag folding.

[0045] A fluid circulation layer 110a is formed between the first end plate 111 and the heat-shielding intermediate plate 113. Therefore, the first battery cell 2a can be cooled by fluid flowing through the fluid circulation layer 110a. Furthermore, a fluid circulation layer 110b is formed between the second end plate 112 and the heat-shielding intermediate plate 113. Therefore, the second battery cell 2b can be cooled by fluid flowing through the fluid circulation layer 110b. In this way, the buffer spacer 101 has a cooling function and a function of absorbing gap fluctuations associated with deformation during normal operation of the first battery cell 2a and the second battery cell 2b.

[0046] Furthermore, if the first battery cell 2a generates abnormal heat, the radiant heat from the first battery cell 2a is cooled by the fluid in the fluid flow layer 110a as it passes through the fluid flow layer 110a between the first end plate 111 and the heat-shielding intermediate plate 113. However, the radiant heat from the first battery cell 2a may pass through the fluid flow layer 110a and reach the heat-shielding intermediate plate 113. Here, the heat-shielding intermediate plate 113 can block the radiant heat from the first battery cell 2a.

[0047] Therefore, after passing through the fluid flow layer 110a, the radiant heat from the first battery cell 2a can be shielded by the heat-shielding intermediate plate 113, and can be prevented from being transmitted downstream in the direction of radiant heat transmission from the heat-shielding intermediate plate 113. Therefore, when the first battery cell 2a abnormally generates heat, the buffer spacer 101 can suppress heat transmission, thereby preventing thermal effects on the second battery cell 2b and surrounding components.

[0048] In particular, the fluid circulation layers 110a, 110b, which are the internal space layers 4a, communicate with the surrounding space 5 of the buffer spacer 4. Therefore, fluid can be convected between the fluid circulation layers 110a, 110b, which are the internal space layers 4a, and the surrounding space 5. That is, heated fluid in the fluid circulation layers 110a, 110b, which are the internal space layers 4a, can flow out into the surrounding space 5, and further, low-temperature fluid in the surrounding space 5 can flow into the fluid circulation layers 110a, 110b, which are the internal space layers 4a. This convection can provide a high cooling function.

[0049] Furthermore, in addition to radiant heat, heat from the first battery cell 2a is also conducted through the spacer body 110. That is, the heat conduction path from the first battery cell 2a to the second battery cell 2b is the first end plate 111, the elastic portion 114, the heat-shielding intermediate plate 113, the elastic portion 115, and the second end plate 112 in that order. Because the spacer body 110 is formed in a zigzag pattern, the heat conduction path is much longer than the distance between the first battery cell 2a and the second battery cell 2b. By lengthening the heat conduction path in the spacer body 110, the amount of heat transferred from the first battery cell 2a to the second battery cell 2b due to thermal conduction can be reduced even if the first battery cell 2a generates abnormal heat.

[0050] As described above, radiant heat from the first battery cell 2a is cooled by the fluid flow layer 110a and further shielded by the heat-shielding intermediate plate 113. Furthermore, heat from the first battery cell 2a is transferred by thermal conduction in the spacer body 110, but the heat transfer distance in the spacer body 110 can be increased, so the amount of heat transferred to the second battery cell 2b can be significantly reduced. Therefore, when the first battery cell 2a generates abnormal heat, the buffer spacer 101 can suppress heat transfer by thermal radiation and thermal conduction, thereby suppressing thermal effects on the second battery cell 2b and surrounding components.

[0051] Furthermore, the spacer body 110 is formed with the same width over the entire length from the first end plate 111 to the second end plate 112. This allows the effects of the heat-shielding intermediate plate 113 and the effects of the fluid circulation layers 110a, 110b to be effectively exerted. Furthermore, by making the spacer body 110 with the same width, the material yield rate in press processing is improved. Furthermore, if a higher elastic modulus is required, the end portions in the width direction (end portions in the normal direction to the paper surface in FIG. 3) can be folded within a range that does not impair the zigzag structure, or a rib structure extending in the longitudinal direction of the spacer body 110 can be formed.

[0052] (Embodiment 2) As another example of the buffer spacer 4 shown in Fig. 1, a buffer spacer 102 of a second embodiment will be described with reference to Fig. 4. In Fig. 4, the thickness and gap of the buffer spacer 102 are exaggerated, and the actual thickness and gap are small.

[0053] The buffer spacer 102 of this embodiment includes a spacer body 120. The spacer body 120 has a shape similar to that of the spacer body 110 of embodiment 1. That is, the spacer body 120 includes a first end plate 111, a second end plate 112, a heat-shielding intermediate plate 113, and a plurality of elastic portions 114 and 115.

[0054] The spacer body 120 of this embodiment includes a core material 121 and a heat-shielding film 122 on the surface of the core material 121. The core material 121 can be made of metal, such as iron, aluminum, nickel, chromium, titanium, or an alloy containing any of these as its main components. The core material 121 can also be made of resin with a high flexural modulus. For example, the core material 121 can be made by impregnating glass fiber with a thermosetting resin, such as epoxy, polymaleimide, polyimide, phenolic resin, urea resin, melamine resin, or unsaturated polyester resin, and then molding and thermally curing the resin.

[0055] Furthermore, the heat shielding film 122 is formed on all surfaces of the core material 121. Therefore, the heat shielding film 122 is formed on all surfaces of the spacer body 120. Thermoresin (registered trademark) SV600 manufactured by Chugai Shoko Co., Ltd. can be used for the heat shielding film 122. Even if the core material 121 has low heat shielding function, the heat shielding film 122 can exhibit high heat shielding function. The heat shielding film 122 exhibits the function of suppressing heat radiation from the core material 121 to the fluid circulation layers 110a, 110b and heat absorption from the fluid circulation layers 110a, 110b to the core material 121.

[0056] Therefore, heat from the first battery cell 2a is transferred to the first end plate 111, suppressing heat radiation from the first end plate 111 to the fluid circulation layer 110a. Furthermore, heat absorption from the fluid circulation layer 110a to the heat shielding intermediate plate 113 is suppressed. Furthermore, heat radiation from the heat shielding intermediate plate 113 to the fluid circulation layer 110b is suppressed. Furthermore, heat absorption from the fluid circulation layer 110b to the second end plate 112 is suppressed. Similarly, heat radiation from the second battery cell 2b to the first battery cell 2a is suppressed.

[0057] The heat shielding film 122 is preferably formed on the surface of at least the first end plate 111 and the second end plate 112 of the core material 121. When iron is used for the core material 121, the heat shielding effect decreases when iron rusts, so it is preferable to use a material with anti-rust properties for the heat shielding film 122. Furthermore, the heat shielding film 122 is preferably made of an insulating paint to prevent short circuits.

[0058] Furthermore, the heat shielding film 122 is formed on the entire surface of the spacer body 120, and therefore on the first contact surface 111a of the first end plate 111 that comes into contact with the first battery cell 2a. Therefore, the heat shielding film 122 can suppress heat transfer from the first battery cell 2a to the first end plate 111, and from the first end plate 111 to the first battery cell 2a.

[0059] Furthermore, the heat shielding film 122 is formed on the opposing surfaces of the first end plate 111 and the heat shielding intermediate plate 113. Therefore, the heat shielding film 122 can suppress heat transfer by thermal radiation from the first end plate 111 to the heat shielding intermediate plate 113 through the fluid circulation layer 110a, and heat transfer by thermal radiation from the heat shielding intermediate plate 113 to the first end plate 111 through the fluid circulation layer 110a.

[0060] Furthermore, the heat shielding film 122 is formed on the opposing surfaces of the second end plate 112 and the heat shielding intermediate plate 113. Therefore, the heat shielding film 122 can suppress heat transfer by thermal radiation from the second end plate 112 to the heat shielding intermediate plate 113 through the fluid circulation layer 110b, and heat transfer by thermal radiation from the heat shielding intermediate plate 113 to the second end plate 112 through the fluid circulation layer 110b.

[0061] The heat shielding film 122 is formed on the second contact surface 112a of the second end plate 112 that comes into contact with the second battery cell 2b. Therefore, the heat shielding film 122 can suppress heat transfer from the second battery cell 2b to the second end plate 112, and from the second end plate 112 to the second battery cell 2b.

[0062] (Embodiment 3) As another example of the buffer spacer 4 shown in Fig. 1, a buffer spacer 301 of embodiment 3 will be described with reference to Fig. 5. In Fig. 5, the thickness and gap of the buffer spacer 301 are exaggerated, and the actual thickness and gap are small.

[0063] The buffer spacer 301 of this embodiment includes a spacer body 310. The spacer body 310 has a shape similar to that of the spacer body 120 of embodiment 2. That is, the spacer body 310 includes a first end plate 111, a second end plate 112, a heat-shielding intermediate plate 113, and a plurality of elastic portions 114 and 115.

[0064] The spacer body 310 of this embodiment includes a core material 311 and heat shielding films 312 and 313. The heat shielding film 312 is formed on the surface of the first end plate 111 that comes into contact with the first battery cell 2a (first contact surface 111a). Therefore, the heat shielding film 312 can suppress heat transfer from the first battery cell 2a to the first end plate 111, and from the first end plate 111 to the first battery cell 2a.

[0065] The heat shielding film 313 is formed on the surface (second contact surface 112a) of the second end plate 112 that comes into contact with the second battery cell 2b. Therefore, the heat shielding film 313 can suppress heat transfer from the second battery cell 2b to the second end plate 112, and from the second end plate 112 to the second battery cell 2b.

[0066] (Embodiment 4) As another example of the buffer spacer 4 shown in Fig. 1, a buffer spacer 302 according to a fourth embodiment will be described with reference to Fig. 6. In Fig. 6, the thickness and gap of the buffer spacer 302 are exaggerated, and the actual thickness and gap are small.

[0067] The buffer spacer 302 of this embodiment includes a spacer body 320. The spacer body 320 has a shape similar to that of the spacer body 310 of embodiment 3. That is, the spacer body 320 includes a first end plate 111, a second end plate 112, a heat-shielding intermediate plate 113, and a plurality of elastic portions 114 and 115.

[0068] The spacer body 320 of this embodiment includes a core material 311, contact surface heat shielding films 312 and 313, flow layer heat shielding films 321 and 322, and heat radiation films 323 and 324. The core material 311 and the contact surface heat shielding films 312 and 313 have the same configuration as the core material 311 and the heat shielding films 312 and 313 of the third embodiment.

[0069] The flow-through layer heat-shielding film 321 is formed on the surface of the first end plate 111, which is one of the components forming the fluid flow-through layer 110a, facing the fluid flow-through layer 110a. The flow-through layer heat-shielding film 322 is formed on the surface of the second end plate 112, which is one of the components forming the fluid flow-through layer 110b, facing the fluid flow-through layer 110b.

[0070] The heat radiation film 323 is formed on the surface of the heat shielding intermediate plate 113, which is the other member forming the fluid circulation layer 110a, that faces the fluid circulation layer 110a. The heat radiation film 324 is formed on the surface of the heat shielding intermediate plate 113, which is the other member forming the fluid circulation layer 110b, that faces the fluid circulation layer 110b.

[0071] Focusing on the fluid circulation layer 110a, a circulation layer heat shielding film 321 is formed on the surface of the first end plate 111, and a heat radiation film 323 is formed on the surface of the heat shielding intermediate plate 113. Therefore, heat transferred to the heat shielding intermediate plate 113 is radiated to the fluid circulation layer 110a via the heat radiation film 323. However, because the circulation layer heat shielding film 321 is formed on the surface of the first end plate 111, the heat radiated to the fluid circulation layer 110a is prevented from being absorbed by the first end plate 111.

[0072] As a result, the heat radiated to the fluid circulation layer 110a tends to remain in the fluid circulation layer 110a without being absorbed by the first end plate 111. However, since the fluid circulation layer 110a is in communication with the surrounding space 5 (shown in FIG. 1) of the buffer spacer 302, convection occurs between the fluid circulation layer 110a and the surrounding space 5. Therefore, the heat radiated to the fluid circulation layer 110a convects with the surrounding space 5, thereby providing a cooling function.

[0073] When focusing on the fluid circulation layer 110b, a circulation layer heat shielding film 322 is formed on the surface of the second end plate 112, and a heat radiation film 324 is formed on the surface of the heat shielding intermediate plate 113. Therefore, heat transferred to the heat shielding intermediate plate 113 is radiated to the fluid circulation layer 110b via the heat radiation film 324. However, because the circulation layer heat shielding film 322 is formed on the surface of the second end plate 112, the heat radiated to the fluid circulation layer 110b is prevented from being absorbed by the second end plate 112.

[0074] As a result, the heat radiated to the fluid circulation layer 110b tends to remain in the fluid circulation layer 110b without being absorbed by the second end plate 112. However, since the fluid circulation layer 110b is in communication with the surrounding space 5 (shown in FIG. 1) of the buffer spacer 302, convection occurs between the fluid circulation layer 110b and the surrounding space 5. Therefore, the heat radiated to the fluid circulation layer 110b convects with the surrounding space 5, thereby providing a cooling function.

[0075] The heat radiation films 323 and 324 may be made of a heat-resistant black spray paint manufactured by Asahipen Co., Ltd. Alternatively, the heat radiation films 323 and 324 may be made of an iron oxide film formed by heat treating the surface of the core material 311.

[0076] (Embodiment 5) As another example of the buffer spacer 4 shown in Fig. 1, a buffer spacer 303 according to a fifth embodiment will be described with reference to Fig. 7 and Fig. 8. In Fig. 7 and Fig. 8, the thickness and gaps of the buffer spacer 303 are exaggerated, and the actual thickness and gaps are small.

[0077] The buffer spacer 303 of this embodiment includes a spacer body 330. The spacer body 330 has a shape similar to that of the spacer body 320 of embodiment 4. That is, the spacer body 330 includes a first end plate 111, a second end plate 112, a heat-shielding intermediate plate 113, and a plurality of elastic portions 114 and 115.

[0078] The spacer body 330 of this embodiment includes a core material 331, flow-through layer heat shielding films 321 and 322, and heat radiation films 323 and 324. The flow-through layer heat shielding films 321 and 322 and the heat radiation films 323 and 324 have the same configuration as in the fourth embodiment.

[0079] The core 331 has multiple recesses 331a formed on the surface of the first end plate 111 that comes into contact with the first battery cell 2a. The multiple recesses 331a are formed independently of each other. Furthermore, the multiple recesses 331a are formed so as not to communicate with the periphery of the first end plate 111.

[0080] Additionally, multiple recesses 331b are formed on the surface of the core 331 on the side of the second end plate 112 that comes into contact with the second battery cell 2b. The multiple recesses 331b are formed independently of each other. Furthermore, the multiple recesses 331b are formed so as not to communicate with the periphery of the second end plate 112.

[0081] The recesses 331a reduce the contact area of ​​the first end plate 111 with the first battery cell 2a. In other words, the recesses 331a function to suppress heat transfer from the first battery cell 2a to the first end plate 111 and from the first end plate 111 to the first battery cell 2a.

[0082] The recesses 331b also reduce the area of ​​contact between the second end plate 112 and the second battery cell 2b. In other words, the recesses 331b function to suppress heat transfer from the second battery cell 2b to the second end plate 112 and from the second end plate 112 to the second battery cell 2b.

[0083] (Modification of the fifth embodiment) A buffer spacer 303a according to a modification of the fifth embodiment will be described with reference to Fig. 9. The buffer spacer 303a of this embodiment includes a spacer body 330a. The spacer body 330a includes a first end plate 111, a second end plate 112, a heat-shielding intermediate plate 113, and a plurality of elastic portions 114 and 115.

[0084] The spacer body 330a of this embodiment includes a core material 331, contact surface heat shielding films 332 and 333, flow-through layer heat shielding films 321 and 322, and heat radiation films 323 and 324. The core material 331, flow-through layer heat shielding films 321 and 322, and heat radiation films 323 and 324 have the same configurations as those in the fifth embodiment.

[0085] The contact surface heat-shielding film 332 is formed on the surface (first contact surface 111a) of the first end plate 111 that comes into contact with the first battery cell 2a. The contact surface heat-shielding film 332 has multiple recesses 332a. The multiple recesses 332a of the contact surface heat-shielding film 332 are located on the surfaces of the multiple recesses 331a of the core material 331.

[0086] The contact surface heat-shielding film 333 is formed on the surface (second contact surface 112a) of the second end plate 112 that comes into contact with the second battery cell 2b. The contact surface heat-shielding film 333 has multiple recesses 333a. The multiple recesses 333a of the contact surface heat-shielding film 333 are located on the surfaces of the multiple recesses 331b of the core material 331.

[0087] In this embodiment, in addition to the same effects as in the fifth embodiment, the same effects as in the third embodiment are also achieved.

[0088] (Embodiment 6) As another example of the buffer spacer 4 shown in Fig. 1, a buffer spacer 304 of a sixth embodiment will be described with reference to Fig. 10 and Fig. 11. In Fig. 10 and Fig. 11, the thickness and gap of the buffer spacer 303 are exaggerated, and the actual thickness and gap are small.

[0089] The buffer spacer 304 of this embodiment includes a spacer body 340. The spacer body 340 has a shape similar to that of the spacer body 320 of embodiment 4. That is, the spacer body 340 includes a first end plate 111, a second end plate 112, a heat-shielding intermediate plate 113, and a plurality of elastic portions 114 and 115.

[0090] The spacer body 340 of this embodiment includes a core material 341, flow-through layer heat shielding films 321 and 322, and heat radiation films 323 and 324. The flow-through layer heat shielding films 321 and 322 and the heat radiation films 323 and 324 have the same configuration as in the fourth embodiment.

[0091] The core 341 has multiple recesses 341a formed on the surface of the first end plate 111 that comes into contact with the first battery cell 2a. The multiple recesses 341a are formed independently of each other. Furthermore, the multiple recesses 341a are grooves that can communicate with the surrounding space 5 of the first end plate 111.

[0092] Additionally, multiple recesses 341b are formed in the surface of the core 341 on the side of the second end plate 112 that comes into contact with the second battery cell 2b. The multiple recesses 341b are formed independently of each other. Furthermore, the multiple recesses 341b are grooves that can communicate with the surrounding space 5 of the second end plate 112.

[0093] The recesses 341a reduce the area of ​​the first end plate 111 that comes into contact with the first battery cell 2a. That is, the recesses 341a function to suppress heat transfer from the first battery cell 2a to the first end plate 111, and from the first end plate 111 to the first battery cell 2a. Furthermore, the recesses 341a are grooves that can communicate with the surrounding space 5. Therefore, fluid in the recesses 341a convects between the recesses 341a and the surrounding space 5, providing a high level of cooling performance.

[0094] The recesses 341b also reduce the area of ​​the second end plate 112 that comes into contact with the second battery cell 2b. That is, the recesses 341b function to suppress heat transfer from the second battery cell 2b to the second end plate 112, and from the second end plate 112 to the second battery cell 2b. Furthermore, the recesses 341b are grooves that can communicate with the surrounding space 5. Therefore, the fluid in the recesses 341b convects between the recesses 341b and the surrounding space 5, providing a high level of cooling performance.

[0095] Furthermore, in the core material 341, the heat shielding intermediate plate 113 has a rib 341c that extends in a direction from the elastic portion 114 that constitutes one folded portion toward the elastic portion 115 that constitutes the other folded portion. The heat shielding intermediate plate 113 can have high rigidity. When the gap between the first battery cell 2a and the second battery cell 2b changes due to expansion and contraction of the first battery cell 2a and the second battery cell 2b, the rib 341c can prevent the heat shielding intermediate plate 113 from being flexurally deformed.

[0096] (Modification of the sixth embodiment) A buffer spacer 304a according to a modification of the sixth embodiment will be described with reference to Fig. 12. The buffer spacer 304a of this embodiment includes a spacer body 340a. The spacer body 340a includes a first end plate 111, a second end plate 112, a heat-shielding intermediate plate 113, and a plurality of elastic portions 114 and 115.

[0097] The spacer body 340a of this embodiment includes a core material 341, contact surface heat shielding films 342 and 343, flow-through layer heat shielding films 321 and 322, and heat radiation films 323 and 324. The core material 341, flow-through layer heat shielding films 321 and 322, and heat radiation films 323 and 324 have the same configurations as those in the sixth embodiment.

[0098] The contact surface heat-shielding film 342 is formed on the surface (first contact surface 111a) of the first end plate 111 that comes into contact with the first battery cell 2a. The contact surface heat-shielding film 342 has multiple recesses 342a. The multiple recesses 342a of the contact surface heat-shielding film 342 are grooves that can communicate with the surrounding space 5 of the first end plate 111. The multiple recesses 342a of the contact surface heat-shielding film 342 are located on the surface of the multiple recesses 341a of the core material 341.

[0099] The contact surface heat-shielding film 343 is formed on the surface (second contact surface 112a) of the second end plate 112 that comes into contact with the second battery cell 2b. The contact surface heat-shielding film 343 has multiple recesses 343a. The multiple recesses 343a of the contact surface heat-shielding film 343 are grooves that can communicate with the surrounding space 5 of the second end plate 112. The multiple recesses 343a of the contact surface heat-shielding film 343 are located on the surface of the multiple recesses 341b of the core material 341.

[0100] In this embodiment, in addition to the same effects as in the sixth embodiment, the same effects as in the third embodiment are also achieved.

[0101] (Embodiment 7) As another example of the buffer spacer 4 shown in Fig. 1, a buffer spacer 103 of a seventh embodiment will be described with reference to Figs. 13 and 14. In Figs. 13 and 14, the thickness and gaps of the buffer spacer 103 are exaggerated, and the actual thickness and gaps are small. Furthermore, in the buffer spacer 103 of this embodiment, the configurations not described below are the same as those of the buffer spacer 101 of the first embodiment.

[0102] The buffer spacer 103 is disposed in the gap between the first battery cell 2a and the support members 3a and 3b, and absorbs gap fluctuations that accompany expansion and contraction of the first battery cell 2a.

[0103] The spacer body 130 is made of a leaf spring and is folded three times. In this embodiment, the spacer body 110 has three folded parts, but it may have four or more folded parts.

[0104] The spacer body 130 includes a first end plate 131, a second end plate 132, a heat-shielding intermediate plate 133, a low-thermal-conductivity intermediate plate 134, and multiple elastic portions 135, 136, and 137. The first end plate 131 has a first contact surface 131a that comes into surface contact with the flat surface of the first battery cell 2a. The second end plate 132 has a second contact surface 132a that comes into surface contact with the support members 3a and 3b.

[0105] The heat shielding intermediate plate 133 is disposed at a distance from the rear surface of the first contact surface 131a of the first end plate 131. The opposing space between the heat shielding intermediate plate 133 and the first end plate 131 forms a fluid circulation layer 130a, which serves as the internal space layer 4a in FIG. 1. In other words, the heat shielding intermediate plate 133 is disposed opposite the first end plate 131 with the fluid circulation layer 130a interposed therebetween. Therefore, the fluid circulation layer 130a exerts the effect of cooling the radiant heat of the first battery cell 2a. Furthermore, the heat shielding intermediate plate 133 is disposed at a distance from the rear surface of the second contact surface 132a of the second end plate 132.

[0106] The heat-shielding intermediate plate 133 is disposed opposite most of the flat surface of the first battery cell 2a, including at least the central portion, and blocks radiant heat from the first battery cell 2a. Therefore, the radiant heat from the first battery cell 2a is cooled by the fluid flow layer 130a and then transferred to the heat-shielding intermediate plate 133, but the amount of heat transferred from the heat-shielding intermediate plate 133 to the opposite surface is reduced. In particular, the heat-shielding intermediate plate 133 is formed as a plate without holes. Therefore, the heat-shielding intermediate plate 133 does not have any portions through which radiant heat from the first battery cell 2a passes directly. Therefore, the heat-shielding intermediate plate 133 exhibits a high heat-shielding effect.

[0107] The low thermal conductive intermediate plate 134 faces, at a distance, the backside of the surface of the heat shielding intermediate plate 133 that faces the first end plate 131. The opposing space between the low thermal conductive intermediate plate 134 and the heat shielding intermediate plate 133 forms a fluid circulation layer 130b, which serves as the internal space layer 4a in FIG. 1. In other words, the low thermal conductive intermediate plate 134 is disposed opposite the heat shielding intermediate plate 133 with the fluid circulation layer 130b interposed therebetween. Therefore, the fluid circulation layer 130b has the effect of cooling the radiant heat of the first battery cell 2a.

[0108] The low thermal conductive intermediate plate 134 is disposed facing, at a distance, the rear surface of the second contact surface 132a of the second end plate 132. That is, the opposing space between the low thermal conductive intermediate plate 134 and the second end plate 132 forms a fluid circulation layer 130c that exerts a cooling effect. The fluid circulation layer 130c functions as the internal space layer 4a in FIG. 1.

[0109] Furthermore, the low thermal conductive intermediate plate 134 is formed so as to transfer less heat by thermal conduction than the heat shielding intermediate plate 133. In this embodiment, the low thermal conductive intermediate plate 134 is formed in a plate shape having holes 134a, as shown in Fig. 14. By forming the holes 134a, the cross-sectional area perpendicular to the direction of heat conduction in the portion where the material of the low thermal conductive intermediate plate 134 exists becomes smaller, and therefore the heat conduction can be reduced.

[0110] In this embodiment, the low thermal conductive intermediate plate 134 has multiple circular holes 134a, but it may have one large hole, such as a rectangular hole. However, the low thermal conductive intermediate plate 134 needs to have a bending modulus that allows it to maintain its shape to some extent when the first battery cell 2a is deformed. Therefore, the size of the hole 134a should be determined according to the required bending modulus.

[0111] The elastic portion 135 connects an end portion (lower end in FIG. 13 ) of the first end plate 131 to one end (lower end in FIG. 13 ) of the heat shielding intermediate plate 133. The elastic portion 136 connects the other end (upper end in FIG. 13 ) of the heat shielding intermediate plate 133 to one end (upper end in FIG. 13 ) of the low thermal conductive intermediate plate 134. The elastic portion 137 connects the other end (lower end in FIG. 13 ) of the low thermal conductive intermediate plate 134 to an end portion (lower end in FIG. 13 ) of the second end plate 132. Elastic deformation of the elastic portions 135, 136, and 137 allows the first end plate 131 to press against the first battery cell 2a.

[0112] The following describes the effects of the buffer spacer 103 having the above-described spacer body 130. The spacer body 130 provides the same effects as the spacer body 110 of the buffer spacer 101 of the first embodiment.

[0113] In addition to radiant heat, heat from the first battery cell 2a is conducted through the spacer body 130. The heat conduction path from the first battery cell 2a to the support members 3a and 3b is the first end plate 131, elastic portion 135, heat-shielding intermediate plate 133, elastic portion 136, low-thermal-conductivity intermediate plate 134, elastic portion 137, and second end plate 132 in that order. Because the spacer body 130 is formed in a zigzag pattern, the heat conduction path is much longer than the distance between the first battery cell 2a and the support members 3a and 3b. By lengthening the heat conduction path in the spacer body 130, the amount of heat transferred by heat conduction from the first battery cell 2a to the support members 3a and 3b can be reduced even if the first battery cell 2a generates abnormal heat.

[0114] Furthermore, the spacer body 130 includes a low-thermal-conductivity intermediate plate 134. The low-thermal-conductivity intermediate plate 134 has holes 134a, which gives it low thermal conductivity. This reduces the amount of heat transferred by thermal conduction from the first battery cell 2a to the support members 3a and 3b. Because the low-thermal-conductivity intermediate plate 134 has holes 134a, radiant heat is easily transferred by passing through the holes 134a. However, the heat-shielding intermediate plate 133 is positioned closer to the first battery cell 2a, which is the heat source, than the low-thermal-conductivity intermediate plate 134. Therefore, because the heat-shielding intermediate plate 133 blocks radiant heat from the first battery cell 2a, the impact of the low-thermal-conductivity intermediate plate 134 having holes 134a is small.

[0115] (Embodiment 8) As another example of the buffer spacer 4 shown in Fig. 1, a buffer spacer 104 of embodiment 8 will be described with reference to Fig. 15. In Fig. 15, the thickness and gap of the buffer spacer 104 are exaggerated, and the actual thickness and gap are small. Furthermore, in the buffer spacer 104 of this embodiment, the configurations not described below are the same as those of the buffer spacer 101 of embodiment 1.

[0116] The buffer spacer 104 is disposed in the gap between the first battery cell 2 a and the second battery cell 2 b, and absorbs gap fluctuations that occur due to expansion and contraction of the first battery cell 2 a and the second battery cell 2 b. The buffer spacer 104 includes a spacer body 140 and a fusible member 150.

[0117] The spacer body 140 includes a first end plate 141, a second end plate 142, a first heat insulating intermediate plate 143, a second heat insulating intermediate plate 144, and a plurality of elastic portions 145, 146, and 147. The first end plate 141 and the second end plate 142 are the same as the first end plate 111 and the second end plate 112 of the first embodiment.

[0118] The first heat shielding intermediate plate 143 is disposed opposite the rear surface of the first contact surface 141a of the first end plate 141, with a fluid circulation layer 140a (internal space layer 4a) in FIG. 1 interposed therebetween. The second heat shielding intermediate plate 144 is disposed opposite the rear surface of the second contact surface 142a of the second end plate 142, with a fluid circulation layer 140b (internal space layer 4a) in FIG. 1 interposed therebetween. The first heat shielding intermediate plate 143 and the second heat shielding intermediate plate 144 have the same function as the heat shielding intermediate plate 113 of the first embodiment. The first heat shielding intermediate plate 143 and the second heat shielding intermediate plate 144 are disposed opposite each other with an opposing region 140c interposed therebetween.

[0119] The elastic portion 145 connects an end portion (lower end in FIG. 15) of the first end plate 141 and one end (lower end in FIG. 15) of the first heat shielding intermediate plate 143. The elastic portion 146 connects the other end (upper end in FIG. 15) of the first heat shielding intermediate plate 143 and one end (upper end in FIG. 15) of the second heat shielding intermediate plate 144. The elastic portion 147 connects the other end (lower end in FIG. 15) of the second heat shielding intermediate plate 144 and an end portion (lower end in FIG. 15) of the second end plate 142.

[0120] The elastic deformation of the multiple elastic portions 145, 146, and 147 allows the first end plate 141 to press against the first battery cell 2a, and the second end plate 142 to press against the second battery cell 2b. The multiple elastic portions 145, 146, and 147 are formed in a bent shape without holes. The lack of holes in the elastic portions 145, 146, and 147 allows them to exert high elastic force.

[0121] The melting member 150 of the buffer spacer 104 contacts the spacer body 140, is formed from a material with a lower melting point than the spacer body 140, and converts conductive heat into heat of fusion. In this embodiment, the melting member 150 is disposed in the opposing region 140c of the first heat shielding intermediate plate 143 and the second heat shielding intermediate plate 144. In particular, the melting member 150 is sandwiched between the first heat shielding intermediate plate 143 and the second heat shielding intermediate plate 144 and is disposed in contact with both of them.

[0122] For example, resin, solder, or the like can be used as the melting member 150. A material with a melting point lower than the upper limit temperature at which heat transfer is permitted is used as the melting member 150. For example, if the upper limit temperature at which heat transfer is permitted is set to 150°C, then resin, solder, or the like with a melting point lower than 150°C is used as the melting member 150. For example, if the upper limit temperature is set to 170°C, then polypropylene or the like is used as the melting member 150, and if the upper limit temperature is set to 265°C, then nylon 66 or the like is used.

[0123] That is, when the temperature of the heat transferred to the area where the melting element 150 is placed exceeds 150°C, the heat can be absorbed by melting the melting element 150. Then, the amount of heat transferred beyond the melting element 150 is reduced.

[0124] Here, the fluid flow layer 140a and the first heat-shielding intermediate plate 143 are interposed between the melting member 150 and the first battery cell 2a. In other words, the melting member 150 is not in contact with the first end plate 141. This allows the melting member 150 to cool to a certain extent before heat is transferred to the melting member 150.

[0125] Furthermore, the melting member 150 is in contact with the first heat shielding intermediate plate 143. Therefore, heat is conducted directly to the melting member 150 from the first heat shielding intermediate plate 143. In parallel with the heat conduction from the first heat shielding intermediate plate 143 to the second heat shielding intermediate plate 144 via the elastic portion 146, heat is conducted to the melting member 150 from the first heat shielding intermediate plate 143. Therefore, the amount of heat conducted from the first heat shielding intermediate plate 143 to the second heat shielding intermediate plate 144 can be reduced.

[0126] In addition, the fusing members 150 can suppress deflection of the first heat shielding intermediate plate 143 and the second heat shielding intermediate plate 144, and therefore can exert a high elastic force during normal operation. Furthermore, the fusing members 150 are formed in a plate shape and are arranged over most of the space between the first heat shielding intermediate plate 143 and the second heat shielding intermediate plate 144. Alternatively, the fusing members 150 may be formed in any shape, such as a rod or a dot, and multiple fusing members 150 may be arranged between the first heat shielding intermediate plate 143 and the second heat shielding intermediate plate 144.

[0127] In particular, solder has a higher heat of fusion but a larger mass than resin. Therefore, when solder is used as fusing member 150, by disposing fusing member 150 only in a partial area rather than over the entire area between first heat shielding intermediate plate 143 and second heat shielding intermediate plate 144, it is possible to reduce the amount of heat transfer due to the heat of fusion while suppressing an increase in mass.

[0128] (Embodiment 9) As another example of the buffer spacer 4 shown in Fig. 1, a buffer spacer 105 of a ninth embodiment will be described with reference to Fig. 16. In Fig. 16, the thickness and gaps of the buffer spacer 105 are exaggerated, and the actual thickness and gaps are small. Furthermore, the configuration of the buffer spacer 105 of this embodiment that is not described below is the same as that of the buffer spacer 103 of the seventh embodiment.

[0129] The buffer spacer 105 comprises a spacer body 130 and a fusing member 160. The spacer body 130 is the same as the spacer body 130 of the seventh embodiment. The fusing member 160 is molded from the same material as the fusing member 150 of the eighth embodiment.

[0130] In this embodiment, the fusing member 160 is disposed between the low thermal conductive intermediate plate 134 and the second end plate 132. In particular, the fusing member 160 is in contact with the low thermal conductive intermediate plate 134. However, the fusing member 160 may be sandwiched between the low thermal conductive intermediate plate 134 and the second end plate 132 and disposed in contact with both.

[0131] Furthermore, the melting member 160 is in contact with the low thermal conductive intermediate plate 134. Therefore, heat is conducted directly to the melting member 160 from the low thermal conductive intermediate plate 134. In parallel with the heat conduction from the low thermal conductive intermediate plate 134 to the second end plate 132 via the elastic portion 137, heat is conducted to the melting member 160 from the low thermal conductive intermediate plate 134. Therefore, the amount of heat conducted from the low thermal conductive intermediate plate 134 to the second end plate 132 can be reduced.

[0132] (Embodiment 10) As another example of the buffer spacer 4 shown in Fig. 1, a buffer spacer 106 of a tenth embodiment will be described with reference to Fig. 17. In Fig. 17, the thickness and gaps of the buffer spacer 106 are exaggerated, and the actual thickness and gaps are small. Furthermore, the configuration of the buffer spacer 106 of this embodiment that is not described below is the same as that of the buffer spacer 101 of the first embodiment.

[0133] The buffer spacer 106 includes a spacer body 170. The spacer body 170 includes a first end plate 171, a second end plate 172, a heat-shielding intermediate plate 173, and a plurality of elastic portions 174 and 175. The first end plate 171, the second end plate 172, and the plurality of elastic portions 174 and 175 are similar to the corresponding components of the spacer body 110 of the first embodiment. A fluid circulation layer 170a serving as the internal space layer 4a in FIG. 1 is formed between the heat-shielding intermediate plate 173 and the first end plate 171, and a fluid circulation layer 170b serving as the internal space layer 4a in FIG. 1 is formed between the heat-shielding intermediate plate 173 and the second end plate 172.

[0134] The heat shielding intermediate plate 173 is not flat, but is formed in a wave shape from one folded portion to the other folded portion, thereby making it possible to lengthen the heat conduction path of the heat shielding intermediate plate 173.

[0135] (Embodiment 11) As another example of the buffer spacer 4 shown in Fig. 1, a buffer spacer 107 of an eleventh embodiment will be described with reference to Fig. 18. In Fig. 18, the thickness and gaps of the buffer spacer 107 are exaggerated, and the actual thickness and gaps are small. Furthermore, the configuration of the buffer spacer 107 of this embodiment that is not described below is the same as that of the buffer spacer 103 of the seventh embodiment.

[0136] While the buffer spacer 103 of the seventh embodiment is disposed in the gap between the first battery cell 2a and the support members 3a and 3b, the buffer spacer 107 of this embodiment is disposed in the gap between the first battery cell 2a and the second battery cell 2b. In other words, because heat sources exist on both sides of the buffer spacer 103, the buffer spacer 107 of this embodiment is a modification of the buffer spacer 103 of the seventh embodiment that accommodates the heat sources on both sides.

[0137] The buffer spacer 107 of this embodiment includes a spacer body 180. The spacer body 180 includes a first end plate 181, a second end plate 182, a first heat-shielding intermediate plate 183, a second heat-shielding intermediate plate 184, a low-thermal-conductivity intermediate plate 185, and a plurality of elastic portions 186, 187, 188, and 189. The spacer body 180 also includes fluid circulation layers 180a, 180b, 180c, and 180d as the internal space layer 4a in FIG. 1 .

[0138] The spacer body 180 can reduce the amount of heat transferred from the first battery cell 2a to the second battery cell 2b, and can also reduce the amount of heat transferred from the second battery cell 2b to the first battery cell 2a.

[0139] (Embodiment 12) As another example of the buffer spacer 4 shown in Fig. 1, a buffer spacer 108 of a twelfth embodiment will be described with reference to Fig. 19. In Fig. 19, the thickness and gaps of the buffer spacer 108 are exaggerated, and the actual thickness and gaps are small. Furthermore, the configuration of the buffer spacer 108 of this embodiment that is not described below is the same as that of the buffer spacer 104 of the eighth embodiment.

[0140] The buffer spacer 108 includes a spacer body 190 and a plurality of fusing members 201, 202, and 203. The spacer body 190 includes a first end plate 191 having a first contact surface 191a, a second end plate 192 having a second contact surface 192a, a first heat insulating intermediate plate 193, a second heat insulating intermediate plate 194, and a plurality of elastic portions 195, 196, and 197. The first end plate 191, the second end plate 192, the first heat insulating intermediate plate 193, the second heat insulating intermediate plate 194, and the plurality of elastic portions 195, 196, and 197 are substantially the same as the first end plate 141, the second end plate 142, the first heat insulating intermediate plate 143, the second heat insulating intermediate plate 144, and the plurality of elastic portions 145, 146, and 147 of the eighth embodiment.

[0141] However, the first end plate 191 is not formed flat over its entire length, but has an end 191b (upper end in FIG. 19) corresponding to a longitudinal end of the spacer body 190 bent toward the inside of the flat thickness of the spacer body 190 (left side in FIG. 19). Similarly, the second end plate 192 has an end 192b (upper end in FIG. 19) corresponding to a longitudinal end of the spacer body 190 bent toward the inside of the flat thickness of the spacer body 190 (right side in FIG. 19). The bent shapes of the end portions 191b, 192b may be curved or tapered.

[0142] The bent shape of the ends 191b, 192b prevents the battery cells 2a, 2b from being scratched when the battery cells 2a, 2b are inserted or when the buffer spacer 108 is inserted. Furthermore, the bent shape of the ends 191b, 192b functions as a rib shape, which increases the strength of the leaf spring.

[0143] Fluid flow layers 190a, 190b, and 190c are formed as the internal space layer 4a in Figure 1 between the first end plate 191 and the first heat-shielding intermediate plate 193, between the second end plate 192 and the second heat-shielding intermediate plate 194, and between the first heat-shielding intermediate plate 193 and the second heat-shielding intermediate plate 194, respectively.

[0144] The melting members 201, 202, and 203 are arranged in the folded inner regions of the elastic portions 195, 196, and 197. Resin or solder can be used for the melting members 201, 202, and 203. By arranging the melting members 201, 202, and 203 in these regions, the melting members 201, 202, and 203 not only reduce the amount of heat transfer by the heat of melting, but also enhance the elastic force of the elastic portions 195, 196, and 197. Therefore, the buffer spacer 108 can exert a high elastic force due to the melting members 201, 202, and 203 and the elastic portions 195, 196, and 197.

[0145] By using solder as the melting members 201, 202, and 203, it is possible to suppress an increase in mass while reducing the amount of heat transfer due to the heat of melting, compared to resin, although solder has a higher heat of fusion.

[0146] (Embodiment 13) As another example of the buffer spacer 4 shown in Fig. 1, a buffer spacer 109 according to a thirteenth embodiment will be described with reference to Fig. 20. In Fig. 20, the thickness and gaps of the buffer spacer 109 are exaggerated, and the actual thickness and gaps are small. Furthermore, the configuration of the buffer spacer 109 according to this embodiment that is not described below is the same as that of the buffer spacer 101 according to the first embodiment.

[0147] The buffer spacer 109 includes a spacer body 210. The spacer body 210 is made of a leaf spring and is formed in a flat spiral shape with two folded portions. In this embodiment, the spacer body 210 has two folded portions, but it may have three or more folded portions.

[0148] The spacer body 210 includes a first end plate 211, a second end plate 212, a heat shielding intermediate plate 213, and a plurality of elastic portions 214, 215. The spacer body 210 is formed to have the same width over the entire length from the first end plate 211 to the heat shielding intermediate plate 213. In other words, the first end plate 211, the second end plate 212, the heat shielding intermediate plate 213, and the plurality of elastic portions 214, 215 are all formed to have the same width.

[0149] The first end plate 211 has a first contact surface 211a that makes surface contact with the flat surface of the first battery cell 2a. An end 211b of the first end plate 211, i.e., a portion corresponding to a longitudinal end of the spacer body 210 (the upper end portion in FIG. 20), is bent toward the inside of the flat thickness of the spacer body 210 (the left side in FIG. 20). The second end plate 212 has a second contact surface 212a that makes surface contact with the flat surface of the second battery cell 2b. The heat-shielding intermediate plate 213 is disposed between the first end plate 211 and the second end plate 212.

[0150] The multiple elastic portions 214, 215 form a flattened spiral folded portion. The multiple elastic portions 214, 215 elastically deform when the gap between the first battery cell 2a and the second battery cell 2b fluctuates as the first battery cell 2a and the second battery cell 2b expand and contract. The elastic portion 214 connects the end of the first end plate 211 (the lower end in FIG. 20 ) to the end of the second end plate 212 (the lower end in FIG. 20 ). The elastic portion 215 connects the end of the second end plate 212 (the upper end in FIG. 20 ) to the end of the heat shielding intermediate plate 213 (the upper end in FIG. 20 ).

[0151] 1 are formed between the first end plate 211 and the heat shielding intermediate plate 213, and between the second end plate 212 and the heat shielding intermediate plate 213. Therefore, according to the buffer spacer 109 of this embodiment, similar to the first embodiment, the effects of the heat shielding intermediate plate 213 and the effects of the fluid circulation layers 210a and 210b are exhibited.

[0152] (others) For example, the spacer body 110 of the buffer spacer 101 of embodiment 1 shown in Fig. 3 can be configured with only the heat-shielding intermediate plate 173, with the heat-shielding intermediate plate 173 being arranged at an angle with respect to the flat surfaces of the first battery cell 2a and the second battery cell 2b. In this case, the heat-shielding intermediate plate 173 has a heat-shielding function as well as an elastic function as a leaf spring.

[0153] In the sixth embodiment shown in Figures 10 and 11, a configuration has been described in which the heat shielding intermediate plate 113 has ribs 341c. As in the seventh, ninth, and eleventh embodiments shown in Figures 13, 16, and 18, in a configuration in which the spacer main bodies 130, 180 have low thermal conductive intermediate plates 134, 185, the low thermal conductive intermediate plates 134, 185 may have ribs similar to those described above. In this case, the heat shielding intermediate plates 133, 183, and 184 and the low thermal conductive intermediate plates 134, 185 may be configured to have ribs. Alternatively, the heat shielding intermediate plates 133, 183, and 184 may not have ribs, and the low thermal conductive intermediate plates 134, 185 may have ribs. [Explanation of symbols]

[0154] 1 battery モジュール 2,2a,2b Battery Cells 3,3a,3b Supporting components 4,101,102,103,104,105,106,107,108,109,301,302,303,303a,304,304a buffer system 5. Peripheral space (fluid circulation space) 110,120,130,140,170,180,190,210,310,320,330,330a,340,340a スペーサ main body 4a, 110a, 110b, 130a, 130b, 130c, 140a, 140b, 170a, 170b, 180a, 180b, 180c, 180d, 190a, 190b, 190c, 210a, 210b Fluid flow layer 111,131,141,171,181,191,211 First end plate 111a, 131a, 141a, 191a, 211a First contact surface 112,132,142,172,182,192,212 Second end plate 112a, 132a, 142a, 192a, 212a Second contact surface 113,133,143,144,173,183,184,193,194,213 Heat shielding intermediate plate 114,115,135,136,137,145,146,147,174,175,186,187,188,189,195,196,197,214,215 Elasticity Department 134,185 Low thermal conductivity intermediate plate 150,160,201,202,203 Melting parts

Claims

1. a buffer spacer for a battery module, the buffer spacer being disposed in a gap between a first battery cell and a second battery cell or in a gap between the first battery cell and a support member, the buffer spacer absorbing gap fluctuations that accompany expansion and contraction of at least the first battery cell; a spacer body formed of a leaf spring and having at least two folded portions; The spacer body includes: a first end plate having a first contact surface that is in surface contact with the first battery cell; a second end plate having a second contact surface that is in surface contact with the second battery cell or the support member; at least one heat-shielding intermediate plate that faces a rear surface of the first contact surface of the first end plate via a fluid flow layer and faces a rear surface of the second contact surface of the second end plate at a distance, and that blocks radiant heat from the first battery cell; a plurality of elastic portions that constitute the folded portion, The heat-shielding intermediate plate has a rib extending in a direction from one of the folded portions to the other of the folded portions.

2. A buffer spacer for a battery module, disposed in a gap between a first battery cell and a second battery cell or in a gap between the first battery cell and a support member, for absorbing gap fluctuations accompanying at least the expansion and contraction of the first battery cell, a spacer body formed of a leaf spring and having at least two folded portions; The spacer body includes: a first end plate having a first contact surface that is in surface contact with the first battery cell; a second end plate having a second contact surface that is in surface contact with the second battery cell or the support member; at least one heat-shielding intermediate plate that faces a rear surface of the first contact surface of the first end plate via a fluid flow layer and faces a rear surface of the second contact surface of the second end plate at a distance, and that blocks radiant heat from the first battery cell; A plurality of elastic portions that form the folded portion; A buffer spacer for a battery module comprising: a low thermal conductivity intermediate plate that faces at a distance the back surface of the heat-shielding intermediate plate that faces the first end plate; and a low thermal conductivity intermediate plate that faces at a distance the back surface of the second contact surface of the second end plate, and that transfers less heat by thermal conduction than the heat-shielding intermediate plate.

3. The heat shield intermediate plate is formed into a plate shape without holes, The buffer spacer for battery modules according to claim 2 , wherein the low thermal conductive intermediate plate is formed in a plate shape having holes.

4. The buffer spacer for battery modules according to claim 3 , wherein the elastic portion does not have a hole.

5. 5. The buffer spacer for battery modules according to claim 2, wherein the low thermal conductive intermediate plate has a rib extending in a direction from one of the folded portions to the other of the folded portions.

6. A buffer spacer for a battery module, which is disposed in the gap between a first battery cell and a second battery cell or in the gap between the first battery cell and a support member, and absorbs gap fluctuations caused by expansion and contraction of at least the first battery cell, a spacer body formed of a leaf spring and having at least two folded portions; The spacer body includes: a first end plate having a first contact surface that is in surface contact with the first battery cell; a second end plate having a second contact surface that is in surface contact with the second battery cell or the support member; at least one heat-shielding intermediate plate that faces a rear surface of the first contact surface of the first end plate via a fluid flow layer and faces a rear surface of the second contact surface of the second end plate at a distance, and that blocks radiant heat from the first battery cell; a plurality of elastic portions that constitute the folded portion, The spacer body has a heat-shielding film on its surface.

7. The buffer spacer for battery modules according to claim 6 , wherein the heat-shielding film is formed on the entire surface of the spacer body.

8. 7. The buffer spacer for battery modules according to claim 6, wherein the heat-shielding film is formed on at least one of a surface of the first end plate that contacts the first battery cell and a surface of the second end plate that contacts the second battery cell.

9. The spacer body includes: a heat-shielding film formed on a surface of one of the members forming the fluid flow layer; 7. The buffer spacer for a battery module according to claim 6, wherein a heat radiation film is formed on a surface of the other member that forms the fluid flow layer.

10. A buffer spacer for a battery module, disposed in a gap between a first battery cell and a second battery cell or in a gap between the first battery cell and a support member, for absorbing gap fluctuations caused by expansion and contraction of at least the first battery cell, a spacer body formed of a leaf spring and having at least two folded portions; The spacer body includes: a first end plate having a first contact surface that is in surface contact with the first battery cell; a second end plate having a second contact surface that is in surface contact with the second battery cell or the support member; at least one heat-shielding intermediate plate that faces a rear surface of the first contact surface of the first end plate via a fluid flow layer and faces a rear surface of the second contact surface of the second end plate at a distance, and that blocks radiant heat from the first battery cell; a plurality of elastic portions that constitute the folded portion, a buffer spacer for a battery module, wherein a recess is formed on the surface of the first end plate that contacts the first battery cell, or on the surface of the second end plate that contacts the second battery cell, so that the buffer spacer is not in contact with the first battery cell or the second battery cell.

11. The buffer spacer for battery modules according to claim 10 , wherein a plurality of the recesses are formed, and the recesses are formed so as not to communicate with the periphery of the first end plate or the second end plate.

12. The buffer spacer for battery modules according to claim 10 , wherein the recess is a groove that can communicate with the periphery of the first end plate or the second end plate.

13. A buffer spacer for a battery module, disposed in a gap between a first battery cell and a second battery cell or in a gap between the first battery cell and a support member, for absorbing gap fluctuations caused by expansion and contraction of at least the first battery cell, a spacer body formed of a leaf spring and having at least two folded portions; a melting member in contact with the spacer body, molded from a material with a lower melting point than the spacer body, for converting conductive heat into melting heat; The spacer body includes: a first end plate having a first contact surface that is in surface contact with the first battery cell; a second end plate having a second contact surface that is in surface contact with the second battery cell or the support member; at least one heat-shielding intermediate plate that faces a rear surface of the first contact surface of the first end plate via a fluid flow layer and faces a rear surface of the second contact surface of the second end plate at a distance, and that blocks radiant heat from the first battery cell; a plurality of elastic portions that form the folded portion.

14. The buffer spacer for battery modules according to claim 13 , wherein the fusing member is not in contact with the first end plate.

15. The buffer spacer for battery modules according to claim 14 , wherein the melting member contacts the heat insulating intermediate plate.

16. A buffer spacer for a battery module, disposed in a gap between a first battery cell and a second battery cell or in a gap between the first battery cell and a support member, for absorbing gap fluctuations accompanying at least the expansion and contraction of the first battery cell, a spacer body formed of a metal leaf spring and having at least two folded portions; The spacer body includes: a first end plate having a first contact surface that is in surface contact with the first battery cell; a second end plate having a second contact surface that is in surface contact with the second battery cell or the support member; at least one heat-shielding intermediate plate that faces a rear surface of the first contact surface of the first end plate via a fluid flow layer and faces a rear surface of the second contact surface of the second end plate at a distance, and that blocks radiant heat from the first battery cell; a plurality of elastic portions that form the folded portion.

17. A buffer spacer for a battery module, disposed in a gap between a first battery cell and a second battery cell or in a gap between the first battery cell and a support member, for absorbing gap fluctuations accompanying at least the expansion and contraction of the first battery cell, a spacer body formed of a resin leaf spring and having at least two folded portions; The spacer body includes: a first end plate having a first contact surface that is in surface contact with the first battery cell; a second end plate having a second contact surface that is in surface contact with the second battery cell or the support member; at least one heat-shielding intermediate plate that faces a rear surface of the first contact surface of the first end plate via a fluid flow layer and faces a rear surface of the second contact surface of the second end plate at a distance, and that blocks radiant heat from the first battery cell; A plurality of elastic portions that form the folded portion; A buffer spacer for a battery module.

18. A buffer spacer for a battery module, disposed in a gap between a first battery cell and a second battery cell or in a gap between the first battery cell and a support member, for absorbing gap fluctuations caused by expansion and contraction of at least the first battery cell, a spacer body formed of a leaf spring and having at least two folded portions; The spacer body includes: a first end plate having a first contact surface that is in surface contact with the first battery cell; a second end plate having a second contact surface that is in surface contact with the second battery cell or the support member; at least one heat-shielding intermediate plate that faces a rear surface of the first contact surface of the first end plate via a fluid flow layer and faces a rear surface of the second contact surface of the second end plate at a distance, and that blocks radiant heat from the first battery cell; a plurality of elastic portions that constitute the folded portion, The heat-shielding intermediate plate is a buffer spacer for a battery module formed in a flat plate shape.

19. A buffer spacer for a battery module, disposed in a gap between a first battery cell and a second battery cell or in a gap between the first battery cell and a support member, for absorbing gap fluctuations accompanying at least the expansion and contraction of the first battery cell, a spacer body formed of a leaf spring and having at least two folded portions; The spacer body includes: a first end plate having a first contact surface that is in surface contact with the first battery cell; a second end plate having a second contact surface that is in surface contact with the second battery cell or the support member; at least one heat-shielding intermediate plate that faces a rear surface of the first contact surface of the first end plate via a fluid flow layer and faces a rear surface of the second contact surface of the second end plate at a distance, and that blocks radiant heat from the first battery cell; a plurality of elastic portions that constitute the folded portion, The heat shielding intermediate plate is formed in a wave shape from one of the folded portions to the other of the folded portions.

20. 20. The buffer spacer for a battery module according to claim 1, wherein the spacer body is formed in a zigzag fold with at least two folded portions.

21. A buffer spacer for a battery module, disposed in a gap between a first battery cell and a second battery cell or in a gap between the first battery cell and a support member, for absorbing gap fluctuations accompanying at least the expansion and contraction of the first battery cell, a spacer body formed of a leaf spring and having at least two folded portions and formed in a flat spiral shape; The spacer body includes: a first end plate having a first contact surface that is in surface contact with the first battery cell; a second end plate having a second contact surface that is in surface contact with the second battery cell or the support member; at least one heat-shielding intermediate plate that faces a rear surface of the first contact surface of the first end plate via a fluid flow layer and faces a rear surface of the second contact surface of the second end plate at a distance, and that blocks radiant heat from the first battery cell; a plurality of elastic portions that form the folded portion.

22. a fluid flow space is formed around the buffer spacer for the battery module; The buffer spacer for a battery module according to any one of claims 1 to 21, wherein the buffer spacer for a battery module is formed to allow communication between the fluid flow layer and the fluid flow space, and is configured to generate convection between the fluid flow layer and the fluid flow space.

23. 23. The buffer spacer for a battery module according to claim 22, wherein the fluid flow space is a part of an internal space of a housing that constitutes an outer frame of the battery module.

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