Cushioning material and battery module

Abstract

To provide a novel cushioning material. [Solution] One aspect of the invention is a cushioning member sandwiched between battery cells, comprising a first support plate and a second support plate facing each other in the direction opposite to the battery cells, and a plurality of elastic members sandwiched between the first support plate and the second support plate and capable of compression deformation, wherein each of the plurality of elastic members is fixed to only one of the first support plate and the second support plate, and the plurality of elastic members are arranged in positions that do not overlap each other in the opposing direction.

Description

Technical Field

[0001] The present disclosure relates to a cushion member and a battery module.

Background Art

[0002] Various cushion members have been developed as cushion members sandwiched between battery cells of a battery module (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

[0016] to

[0020] )

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a novel cushion member.

Means for Solving the Problems

[0005] One aspect of the invention is a cushion member sandwiched between battery cells, comprising a first support plate and a second support plate facing each other in the facing direction of the battery cells, and a plurality of elastic members sandwiched between the first support plate and the second support plate and capable of being compressed and deformed, wherein each of the plurality of elastic members is fixed to only one of the first support plate and the second support plate, and the plurality of elastic members are arranged at positions not overlapping each other in the facing direction.

Brief Description of the Drawings

[0006] [Figure 1] FIG. 1 is a perspective view of a battery module in which a cushion member according to a first embodiment is provided between battery cells. [Figure 2]Figure 2A is a side cross-sectional view of the cushioning member sandwiched between battery cells, and Figure 2B is a side cross-sectional view of the first opposing member and the second opposing member that, when joined together, constitute the cushioning member. [Figure 3] Figure 3A is a perspective view of the first opposing member, and Figure 3B is a perspective view of the second opposing member. [Figure 4] Figure 4A is a side cross-sectional view of a cushioning member provided between battery cells in a battery module according to the second embodiment, and Figure 4B is a side cross-sectional view of a first opposing member and a second opposing member that, when joined together, constitute the cushioning member. [Figure 5] Figure 5A is a perspective view of the first opposing member, and Figure 5B is a perspective view of the second opposing member. [Figure 6] Figure 6A is a plan view of the first opposing member, and Figure 6B is a plan view of the second opposing member. [Figure 7] Figure 7 is a cross-sectional view of line AA in Figure 4A. [Figure 8] Figure 8A is a side cross-sectional view of the first support plate set on the lower mold, Figure 8B is a side cross-sectional view of the first rubber molding die assembled on the lower mold and the first support plate, Figure 8C is a side cross-sectional view of the rubber material filled into the first molding hole of the first rubber molding die, and Figure 8D is a side view of the elastic member vulcanized in the first molding hole closed by the upper mold. [Figure 9] Figure 9A is a side cross-sectional view of the second support plate set on the lower mold, Figure 9B is a side cross-sectional view of the second rubber molding die assembled on the lower mold and the second support plate, Figure 9C is a side cross-sectional view of the rubber material filled into the second molding hole of the second rubber molding die, and Figure 9D is a side view of the elastic member vulcanized in the second molding hole closed by the upper mold. [Figure 10] Figure 10A is a side cross-sectional view of a cushioning member provided between battery cells in a battery module according to the third embodiment, and Figure 10B is a side cross-sectional view of a first opposing member and a second opposing member that, when joined together, constitute the cushioning member. [Figure 11] Figure 11 is a side cross-sectional view of a cushioning member provided between battery cells in a battery module according to the fourth embodiment. [Figure 12]Figure 12A is a side cross-sectional view of the first and second opposing members sandwiched between a pair of films, Figure 12B is a side cross-sectional view of the pair of films whose outer edges are sealed together, and Figure 12C is a side cross-sectional view of the cushion member with the outer edges of the pair of films cut off. [Figure 13] Figure 13A is a side cross-sectional view of a pair of opposing members constituting a cushion member according to another embodiment, and Figure 13B is a perspective view of the opposing members. [Figure 14] Figure 14A is a plan view of opposing members constituting a cushion member according to another embodiment, and Figure 14B is a plan cross-sectional view of the elastic members of a pair of opposing members joined together. [Modes for carrying out the invention]

[0007] [First Embodiment] Figure 1 shows a cushion member 10 according to the first embodiment. The cushion member 10 is provided in the battery module 50. The battery module 50 is provided with a plurality of battery cells 51 stacked on top of each other with a predetermined interval between them. The electrodes 52 of the plurality of battery cells 51 are connected to each other. The cushion member 10 is placed between the battery cells 51 and sandwiched between them. Note that the detailed structure of the cushion member 10 is omitted in Figure 1.

[0008] In this embodiment, the battery cells 51 are flat and stacked in the thickness direction. Also in this embodiment, the cushioning member 10 is also flat and sandwiched between the battery cells 51 in the thickness direction. Furthermore, in this embodiment, the battery cells 51 and the cushioning member 10 are stacked horizontally. For example, the battery module 50 is installed in a vehicle (e.g., an electric vehicle) (for example, used as a drive battery).

[0009] As shown in Figure 2A, the cushioning member 10 comprises a pair of support plates 11 and an elastic member 20. The pair of support plates 11 are positioned opposite each other in the opposing direction H (overlapping direction) of the battery cells 51. In this embodiment, the pair of support plates 11 are the same shape and size, and are positioned directly opposite each other so as to overlap completely in the opposing direction H. In this embodiment, the surface of the cushioning member 10 that contacts the battery cells 51 is flat, allowing the cushioning member 10 and the battery cells 51 to contact each other completely in the opposing direction H.

[0010] The elastic member 20 is positioned between a pair of support plates 11 and is compressible and deformable by being sandwiched between these support plates 11. In this embodiment, multiple elastic members 20 are provided. The multiple elastic members 20 are positioned so as not to overlap each other in the opposing direction H.

[0011] Each of the multiple elastic members 20 is fixed to only one of the pair of support plates 11. In this embodiment, the elastic member 20 includes a first elastic member 20A fixed to only one of the pair of support plates 11, the first support plate 11A, and a second elastic member 20B fixed to only the other second support plate 11B (see Figure 2B). The cushion member 10 is made up of two opposing members 30 (first opposing member 30A) comprising the first support plate 11A and the first elastic member 20A, and an opposing member 30 (second opposing member 30B) comprising the second support plate 11B and the second elastic member 20B, which are superimposed without being bonded together. In this way, since the first opposing member 30A and the second opposing member 30B are joined together in a non-adherent state, the bonding process between the opposing members 30 can be omitted compared to a configuration in which the first opposing member 30A and the second opposing member 30B are bonded together, thereby reducing the effort required to manufacture the cushion member 10.

[0012] When the cushion member 10 is disposed between the battery cells 51, it is preferable that the first opposing member 30A and the second opposing member 30B are always in contact with each other (that is, it is preferable that the first elastic member 20A and the second support plate 11B are in contact with each other, and the second elastic member 20B and the first support plate 11A are in contact with each other). For example, when the cushion member 10 is disposed in this way, the elastic member 20 may be sandwiched between the pair of support plates 11 and may always be in a compressed and deformed state. Since the battery cell 51 expands and contracts with charging and discharging, the first opposing member 30A and the second opposing member 30B may be arranged to contact each other only when the battery cell 51 expands.

[0013] The support plate 11 is preferably made of a material that is more difficult to deform than the elastic member 20. Further, the support plate 11 is preferably made of a material having a higher hardness than the elastic member 20. For example, as the support plate 11, a thin plate that can be deformed to an extent that can follow the expansion and contraction of the battery cell 51 can be used. Regarding the measurement of hardness, a measurement method suitable for comparing the hardness of materials, such as Asker C hardness or Shore A hardness, may be used.

[0014] As an example of a preferable configuration of the cushion member 10, a configuration in which the support plate 11 is made of metal and the elastic member 20 is made of an elastomer such as rubber or thermoplastic elastomer can be cited. In the example of the present embodiment, the first support plate 11A and the second support plate 11B are made of metal, and the elastic member 20 is made of non-foamed rubber. The Asker C hardness of the rubber elastic member 20 is preferably, for example, 20 to 80, and more preferably 40 to 60. Examples of the materials constituting the support plate 11 and the elastic member 20 include the following.

[0015] Examples of the support plate 11 include those made of metal, such as those composed of aluminum, iron, steel, stainless steel or brass, or those containing at least a part of these metals. The support plate 11 may be made of resin. Examples of such a support plate 11 include those composed of polyethylene, polypropylene, polystyrene, polyvinyl chloride, ABS resin, olefin-based elastomer (TPO) or elastomers such as rubber (preferably non-foamed). Note that the first support plate 11A and the second support plate 11B may be made of the same type of material (for example, the same material), or may be made of different types of materials (for example, made of different metals or different resins).

[0016] Examples of the elastic member 20 may include non-foamed materials (for example, those made of elastomers such as rubber or thermoplastic elastomers), foamed materials, or materials containing at least a part of an elastomer or a foamed material. Examples of the rubber constituting the elastic member 20 include ethylene propylene diene rubber (EPDM), styrene butadiene rubber (SBR), acrylonitrile butadiene rubber (NBR), natural rubber (NR), butadiene rubber (BR), acrylic rubber (ACM), ethylene acrylate rubber (AEM), silicone or fluorine rubber (FKM), or those containing at least a part of these. Examples of the thermoplastic elastomer constituting the elastic member 20 include olefin-based elastomer (TPO), styrene-based elastomer (TPS) or polyester-based elastomer (TPEE), urethane-based elastomer (TPU), or those containing at least a part of these. Note that the first elastic member 20A and the second elastic member 20B may be made of the same type of material (for example, the same material), or may be made of different types of materials (for example, different elastomers).

[0017] In this embodiment, as shown in Figures 3A and 3B, the elastic member 20 protrudes from the opposing surfaces 11M of the support plates 11 and extends along the opposing surfaces 11M. Such a protruding structure can be a linear projection (ridge) of the elastic member 20, and in this embodiment, the elastic member 20 extends in a straight line. Such a linear elastic member 20 can be formed, for example, by cutting a long elastic body (e.g., one formed by extrusion molding) to a predetermined length, thus making it easy to form the elastic member 20. Alternatively, when forming the elastic member 20 from rubber, the extruded material can be placed on the support plate 11 and bonded by applying heat for continuous vulcanization. This method also makes it easy to form the elastic member 20 and thus easy to form the opposing members 30.

[0018] In this embodiment, the support plate 11 is rectangular (for example, square). Multiple linear elastic members 20, which are parallel to each other, extend in a first direction H1 along which a pair of opposing sides of the support plate 11 extend. The multiple elastic members 20 are arranged on the support plate 11 at intervals (for example, at equal intervals) in a second direction H2 perpendicular to the first direction H1 (see Figures 2A, 3A, and 3B). As a result, a gap is formed between a pair of support plates 11. In this embodiment, the cushion member 10 is arranged such that the first direction H1 along which the elastic members 20 extend is horizontal, so the gap between a pair of support plates 11 is opened horizontally. Heat transferred from the battery cell 51 to the support plate 11 can then be released through this gap. The battery module 50 may be arranged such that the first direction H1 along which the elastic members 20 extend is vertical.

[0019] In the examples shown in Figures 3A and 3B, multiple first elastic members 20A and second elastic members 20B are provided, with the number of first elastic members 20A (four in this example) being one more than the number of second elastic members 20B (three in this example). For example, two of the four first elastic members 20A are arranged on the two sides of the first support plate 11, and the remaining two first elastic members 20A are placed between them (see Figure 3A). Alternatively, for example, three second elastic members 20B are placed on the second support plate 11B in positions between the first elastic members 20A (see Figure 3B). It is also possible to configure the first elastic members 20A and the second elastic members 20B not to be arranged parallel to each other.

[0020] In this embodiment, the multiple elastic members 20 are formed to be the same shape and size in their uncompressed natural state, and the amount of protrusion (protrusion height) of the elastic members 20 from the support plate 11 is the same.

[0021] As described above, in the cushion member 10 of this embodiment, a plurality of elastic members 20 that can be compressed and deformed between the first support plate 11A and the second support plate 11B are arranged in positions that do not overlap each other in the opposing direction H, and each elastic member 20 is fixed to only one of the first support plate 11A and the second support plate 11B. Thus, according to this embodiment, a novel cushion member 10 that is completely different from conventional cushion members can be provided. Furthermore, the cushion member 10 is composed of two members: a first opposing member 30A comprising the first support plate 11A and the first elastic member 20A, and a second opposing member 30B comprising the second support plate 11B and the second elastic member 20B. Therefore, even a cushion member 10 with a complex shape that is difficult to mold as a single molded product can be easily manufactured.

[0022] Here, if multiple elastic members 20 are fixed (e.g., bonded) to both the first support plate 11A and the second support plate 11B, stress is more likely to be applied to both fixing points, which may cause the elastic members 20 to break or the bond to peel off. In detail, when the battery cell 51 expands and the elastic members 20 are compressed against the pair of support plates 11, if the elastic members 20 are fixed to both of the pair of support plates 11, it is considered that it becomes more difficult to distribute the stress caused by bulging in the shear direction. As a result, there is no place for the force to escape, and it is possible that the weak points where the elastic members 20 and the support plates 11 are fixed (e.g., bonded) may break.

[0023] In contrast, by configuring each of the multiple elastic members 20 to be fixed to only one of the first support plate 11A and the second support plate 11B and not to the other, when the elastic member 20 is compressed, the unfixed portion expands in the shear direction, thereby distributing the stress and preventing excessive localized stress. Furthermore, this expansion in the shear direction increases the contact area between the elastic member 20 and the support plate 11 on which the elastic member 20 is not fixed, thus distributing the stress on this support plate 11. This makes it possible to suppress damage to the elastic member 20 and delamination of the adhesive portion between the elastic member 20 and the support plate 11, thereby improving the durability of the cushion member 10. Moreover, by distributing the stress on the cushion member 10 with the above configuration, it is possible to distribute the reaction force of the cushion member 10 on the battery cell 51, thereby extending the lifespan and performance of the battery cell 51.

[0024] Furthermore, in the cushion member 10 of this embodiment, since the first support plate 11A and the second support plate 11B are made of metal, it is possible to dissipate heat from the battery cell 51 more easily compared to when they are made of resin. Also, as described above, the multiple elastic members 20 are arranged with gaps between them, creating a gap between the support plates 11, and this gap is open in the first direction H1 in which the elastic members 20 extend. Therefore, the heat transferred from the battery cell 51 to the support plate 11 can be dissipated through the gap. As a result, it is possible to extend the lifespan and improve the performance of the battery cell 51.

[0025] Here, if the elastic member 20 is made of foamed resin, depending on the type of battery cell 51, there is a possibility that the reaction force to suppress the expansion of the battery cell 51 may be insufficient. Also, if the elastic member is made of foamed resin, repeated compression deformation tends to leave residual strain deformation, which may reduce the reaction force. In contrast, by making the elastic member out of non-foamed rubber, it becomes easier to secure the necessary reaction force against the expansion of the battery cell, and it is also possible to suppress the reduction in reaction force due to repeated compression deformation.

[0026] In this case, if the contact surface of the cushion member 10 with the battery cell 51 is an uneven surface with multiple protrusions, there is a risk of localized stress concentration in the portion of the battery cell 51 that contacts the multiple protrusions of the cushion member 10. In contrast, in the cushion member 10 of this embodiment, the contact surface with the battery cell 51 is flat due to the presence of the support plate 11, allowing for overall contact with the battery cell 51 in the opposing direction H. Therefore, stress concentration on the battery cell 51 can be suppressed, making it possible to extend the lifespan and improve the performance of the battery cell 51.

[0027] [Second Embodiment] Figure 4A shows the cushion member 10 and battery module 50 according to the second embodiment. In this embodiment, the shape and arrangement of the elastic member 20 differ from those of the first embodiment. The other configurations of this embodiment are the same as those of the first embodiment.

[0028] In the cushion member 10 of this embodiment, the multiple elastic members 20 are columnar in shape with their axial direction extending in the opposing direction H (see Figures 4A and 4B) and are distributed amongst themselves. In this example, the elastic members 20 are cylindrical (see Figures 5A and 5B), but they may also be prismatic (for example, with a regular polygonal cross-section).

[0029] As shown in Figures 6A and 6B, the first elastic member 20A, fixed only to the first support plate 11A, and the second elastic member 20B, fixed only to the second support plate 11B, are positioned offset from each other in the opposing direction H (see Figure 4A). When the first opposing member 30A and the second opposing member 30B are superimposed, the combined elastic members 20 (see Figure 7), consisting of the first elastic member 20A and the second elastic member 20B, are arranged, for example, in a grid pattern (for example, a staggered grid pattern), and are positioned overall on the opposing surface 11M of the support plate 11. The first elastic member 20A and the second elastic member 20B are provided, for example, in a point-symmetrical and line-symmetrical manner with respect to the center of the opposing surface 11M of the support plate 11 (see Figures 6A and 6B). In Figures 6A, 6B, and 7, the circular portions represent the elastic members 20.

[0030] The cushion member 10 of this embodiment can also achieve the same effects as in the first embodiment. In this embodiment, since the columnar elastic members 20 are distributed, it is possible to suppress the localized concentration of reaction force from the elastic members 20 on the battery cell 51.

[0031] In the cushion member 10 of this embodiment, the opposing member 30, which includes a rubber elastic member 20, is manufactured, for example, as follows. Figure 8D shows a first molding die 70A for forming the first opposing member 30A. The first molding die 70A comprises a lower mold 71A, a first rubber molding die 72A, and an upper mold 73A.

[0032] First, the first support plate 11A is placed on the lower mold 71A from above (see Figure 8A). Next, the first rubber molding die 72A is placed on top of the lower mold 71A and the first support plate 11A from above. The first rubber molding die 72A has a first molding hole 72H formed vertically through it for molding the first elastic member 20. The lower opening of the first molding hole 72H is placed on top of the first support plate 11A. A vulcanizing adhesive is applied to the portion of the first support plate 11A that overlaps with the first molding hole 72H to bond the first support plate 11A to the first elastic member 20A made of rubber.

[0033] Next, unvulcanized rubber material 20M is filled into the first molding hole 72H from above. Then, the first molding hole 72H is closed from above by the upper mold 73A. The rubber material 20M in the first molding hole 72H is vulcanized, forming the first elastic member 20A, and the first elastic member 20A adheres to the first support plate 11A (vulcanized adhesion). As a result, the first opposing member 30A is obtained in which the first elastic member 20A is integrated with the first support plate 11A. The first elastic member 20A may be obtained, for example, by injecting liquid rubber material 20M that has been melted by heat into the first molding hole 72H and forming it, or by placing a block of rubber material 20M into the first molding hole 72H and pressing it.

[0034] As shown in Figures 9A to 9D, the process for forming the second opposing member 30B is the same as for forming the first opposing member 30A. The second support plate 11B is placed on top of the lower mold 71B of the second molding die 70B (see Figure 9A), and the second rubber molding die 72B, through which the second molding hole 72U for molding the second elastic member 20B is passed, is placed on top of it. Then, the second molding hole 72U is filled with unvulcanized rubber material 20M, and the second molding hole 72U is closed from above by the upper mold 73B. Then, the rubber material 20M in the second molding hole 72U is vulcanized, the second elastic member 20B is molded, and the second elastic member 20B adheres to the second support plate 11B (vulcanized adhesion). As a result, the second opposing member 30B is obtained in which the second elastic member 20B is integrated with the second support plate 11B.

[0035] In this way, by filling the support plate 11 with unvulcanized rubber material 20M and then vulcanizing and bonding it, the rubber elastic member 20 can be bonded to the support plate 11 more easily and reliably. Alternatively, the elastic member 20 may be molded separately and then fixed to the support plate 11 with adhesive or the like.

[0036] [Third Embodiment] Figures 10A and 10B show the cushion member 10 and battery module 50 of the third embodiment. In this embodiment, the elastic member 20 becomes thicker as it approaches the fixing surface (opposing surface 11M) to the support plate 11 (i.e., toward the base side of the elastic member 20). With this configuration, when the elastic member 20 is compressed and deformed between the pair of support plates 11, it is possible to make the elastic member 20 less likely to buckle. Note that the elastic member 20 in this configuration may be all of the elastic members 20, or it may be at least some of the elastic members 20 of the first elastic member 20A and the second elastic member 20B.

[0037] The other configurations of this embodiment are the same as those of the above embodiment. The cushion member 10 of this embodiment can also achieve the same effects as those of the above embodiment.

[0038] [Fourth Embodiment] Figure 11 shows a cushion member 10 and a battery module 50 according to the fourth embodiment. The cushion member 10 of this embodiment is provided with a holding member 40 that holds a pair of support plates 11 facing each other. The holding member 40 may be a bag (e.g., a pouch) that houses the first opposing member 30A and the second opposing member 30B, or it may be a band-shaped member (e.g., a band or belt) that surrounds and fastens the first support plate 11A and the second support plate 11B.

[0039] Figure 11 shows a pouch as an example of a retaining member 40. The pouch as a retaining member 40 is obtained, for example, by sealing the outer edges of a pair of films 40A and 40B, and is manufactured as follows. First, as shown in Figure 12A, the first opposing members 30A and the second opposing members 30B, which are overlapped with each other, are sandwiched between the lower first film 40A and the upper second film 40B. The first film 40A and the second film 40B are prepared to be large enough to cover the entire opposing member 30 and have their entire outer edges protrude.

[0040] Next, the entire outer edges of the first film 40A and the second film 40B are heat-sealed and thermally fused to form a pouch that serves as a holding member 40. At this time, by vacuuming the air between the films 40A and 40B, the films 40A and 40B can be brought into close contact with the first opposing member 30A and the second opposing member 30B, thereby stabilizing the holding of the first opposing member 30A and the second opposing member 30B.

[0041] The other configurations of this embodiment are the same as those of the above embodiment. The cushion member 10 of this embodiment can also achieve the same effects as those of the above embodiment. In the cushion member 10 of this embodiment, a holding member 40 is provided that holds the first support plate 11A and the second support plate 11B in an opposing state, making it easier to handle the cushion member 10 and improving the workability of assembling the cushion member 10 between the battery cells 51.

[0042] [Other embodiments] In the first embodiment described above, the first opposing member 30A and the second opposing member 30B shown in Figure 13A may be opposing members 30 with the same configuration as shown in Figure 13B (that is, the arrangement of the first elastic member 20A on the first support plate 11A shown in Figure 13A and the arrangement of the second elastic member 20B on the second support plate 11B may be the same as shown in Figure 13B). In this configuration as well, the first elastic member 20A and the second elastic member 20B can be positioned so as not to overlap each other in the opposing direction of the support plates 11. Also, as shown in Figure 14A, in the second embodiment described above, the pair of opposing members 30 constituting the cushion member 10 may have the same configuration. In this configuration as well, as shown in Figure 14B, the first elastic member 20A and the second elastic member 20B can be positioned so as not to overlap each other in the opposing direction of the support plates 11. By standardizing the shape and size of the first opposing member 30A and the second opposing member 30B, it becomes possible to standardize the molding die used in manufacturing. As described above, by making the first opposing member 30A and the second opposing member 30B common (for example, by making the materials common), it becomes possible to improve the manufacturing efficiency and productivity of the cushion member 10.

[0043] In the above embodiment, the materials of the multiple elastic members 20 may be the same or different. For example, the hardness of the multiple elastic members 20 may be the same or different. For example, the hardness of the elastic member 20 corresponding to the portion of the battery cell 51 that expands more in the thickness direction than others may be higher than the hardness of the other elastic members 20. In this configuration, the reaction force of the elastic member 20 can be increased against the portion of the battery cell 51 that is prone to expansion, making it possible to effectively suppress the expansion of the battery cell 51. Furthermore, by setting the hardness of each of the multiple elastic members 20, it is possible to provide the cushion member 10 so that the reaction force of the cushion member 10 is appropriate for each portion of the battery cell 51.

[0044] In the above embodiment, the protrusion height of the elastic members 20 from the support plate 11 may differ among the multiple elastic members 20. For example, when the amount of expansion in the thickness direction of the battery cell 51 exceeds a certain specified value, some of the first elastic members 20 (e.g., first elastic member 20A) may come into contact with the support plate 11 (e.g., second support plate 11B). As an example of such a configuration, the protrusion height of the elastic member 20 facing the central part of the battery cell 51, which is prone to expansion, may be lowered, and the protrusion height of the elastic member 20 facing the outer edge of the battery cell 51 may be lowered. With this configuration as well, it is possible to effectively suppress the expansion of the battery cell 51, and the reaction force of the cushion member 10 can be appropriately adjusted for each part of the battery cell 51.

[0045] In the cushion member 10 of the above embodiment, a fire-resistant heat-insulating material may be layered on the outside of at least one of the pair of support plates 11. In the cushion member 10 of the fourth embodiment, this fire-resistant heat-insulating material may be housed in a bag (e.g., a pouch) that serves as the holding member 40. This configuration enhances the fire resistance and heat insulation of the cushion member 10. This makes it possible to suppress the transfer of heat to other battery cells 51 or the spread of fire in the event that a battery cell 51 becomes too hot or catches fire. Furthermore, by housing the fire-resistant heat-insulating material in a bag such as a pouch, it becomes possible to improve the ease of carrying the opposing member 30 and the fire-resistant heat-insulating material and the ease of assembly between the battery cells 51.

[0046] The support plate 11 and the elastic member 20 may be made of the same material (for example, both may be made of resin). In this case, for example, the support plate 11 and the elastic member 20 may be integrally molded from the same material. In this case, it becomes possible to reduce the number of parts of the cushion member 10 and to simplify the manufacturing of the cushion member 10.

[0047] In this configuration, all of the elastic members 20 may be fixed to one support plate 11, while the elastic members 20 are not fixed to the other support plate 11. In this configuration, only one type of mold is needed to form the elastic members 20, making it possible to easily manufacture the cushion member 10 and reduce the manufacturing cost of the cushion member 10.

[0048] It is also possible to configure the cushion member 10 so that the first opposing member 30A and the second opposing member 30B are bonded together (that is, it is also possible to configure it so that the first support plate 11A and the second elastic member 20B are bonded together, as well as the second support plate 11B and the first elastic member 20A are bonded together).

[0049] The cushion member 10 may be used in a way other than sandwiched between the battery cells 51. For example, the first opposing member 30A and the second opposing member 30B may be arranged so that their opposing directions are vertical, and the cushion member 10 may be used in the floor structure.

[0050] <Note> The following describes the features extracted from the above embodiment, explaining their effects and other aspects as needed.

[0051] For example, the following features of this disclosure relating to cushioning members and battery modules can be considered to have been conceived with the problem of "providing a novel cushioning member," given the background technology that, for example, "various cushioning members have been developed to be sandwiched between battery cells in a battery module (see, for example, Japanese Patent Application Publication No. 4508221 (paragraphs

[0016] to

[0020] ))." There has been a long-standing demand for novel cushioning members, novel battery modules, and novel manufacturing methods for cushioning members.

[0052] [Feature 1] A cushioning material that is placed between battery cells, The first support plate and the second support plate are located opposite each other in the direction in which the battery cells are facing each other. The system comprises a plurality of elastic members that are compressible and deformable when sandwiched between the first support plate and the second support plate, Each of the aforementioned multiple elastic members is fixed to only one of the first support plate and the second support plate. The plurality of elastic members are cushion members arranged in positions that do not overlap each other in the opposing directions.

[0053] [Feature 2] The cushion member according to feature 1, wherein the plurality of elastic members include a first elastic member fixed only to the first support plate and a second elastic member fixed only to the second support plate.

[0054] [Feature 3] The first support plate and the second support plate are both made of metal. The cushion member according to feature 1 or 2, wherein the plurality of elastic members are made of non-foamed rubber.

[0055] [Feature 4] A cushioning member according to any one of features 1 to 3, comprising a holding member for holding the first support plate and the second support plate in an opposing state.

[0056] [Feature 5] The cushion member according to any one of features 1 to 4, wherein the plurality of elastic members protrude from the opposing surfaces of the first support plate and the second support plate, and form a protruding structure that extends along the opposing surfaces.

[0057] [Feature 6] The cushion member according to any one of features 1 to 4, wherein the plurality of elastic members are columnar in shape and protrude from the opposing surfaces of the first support plate and the second support plate.

[0058] [Feature 7] The cushion member according to feature 5 or 6, wherein the first and second elastic members become thicker as they approach the fixing surfaces to the first and second support plates.

[0059] [Feature 8] A battery module in which a cushioning material described in any one of the features 1 through 7 is provided between the battery cells.

[0060] [Feature 9] A method for manufacturing a cushion member according to any one of the features 1 to 7, A first rubber molding die having a first molding hole for molding the first elastic member, and a second rubber molding die having a second molding hole for molding the second elastic member are provided. The process involves placing the first support plate below and the first rubber molding die above, filling the first molding hole with unvulcanized rubber material, molding the first elastic member, and vulcanizing and bonding it to the first support plate, A method for manufacturing a cushion member, comprising the steps of: placing the second support plate below and the second rubber molding die above; filling the second molding hole with unvulcanized rubber material; molding the second elastic member and vulcanizing and bonding it to the second support plate.

[0061] According to the above features 1 and 8, a novel cushioning member can be provided that is sandwiched between battery cells. In this case, if multiple elastic members are fixed (e.g., bonded) to both the first support plate and the second support plate, stress is easily applied to the fixing points, which may cause the elastic members to break or the bond to peel off. In contrast, by configuring each of the multiple elastic members to be fixed to only one of the first support plate and the second support plate and not to the other, it becomes possible to easily release stress and suppress excessive stress in a localized area. This makes it possible to suppress damage to the elastic members and peeling of the bond between the elastic members and the support plates, thereby improving the durability of the cushioning member. Furthermore, by distributing the stress on the cushioning member with the above configuration, it becomes possible to distribute the reaction force of the cushioning member on the battery cells, which can lead to a longer lifespan and higher performance of the battery cells. Furthermore, a cushioning member having such a configuration may include, for example, a plurality of elastic members, a first elastic member fixed only to the first support plate, and a second elastic member fixed only to the second support plate (Feature 2).

[0062] In Feature 3, since the first and second support plates are made of metal, it is possible to dissipate heat from the battery cells more easily compared to when they are made of resin. However, if the elastic member is made of foamed resin, depending on the type of battery cell, there is a possibility that the reaction force to suppress the expansion of the battery cell may be insufficient. Also, if the elastic member is made of foamed resin, repeated compression deformation tends to leave residual strain deformation, which may reduce the reaction force. In contrast, in Feature 3, since the elastic member is made of non-foamed rubber, it is easy to secure the necessary reaction force against the expansion of the battery cell, and it is also possible to suppress the reduction in reaction force due to repeated compression deformation.

[0063] In the cushion member of Feature 4, a holding member is provided to hold the first support plate and the second support plate in an opposing position, making it easier to handle the cushion member and improving the workability of assembling the cushion member between the battery cells.

[0064] In the cushion member of Feature 5, the elastic member protrudes from the opposing surfaces of the first support plate and the second support plate and has a structure that extends along these opposing surfaces. As an example of such a structure, the elastic member may extend in a straight line. In this case, the elastic member can be formed, for example, by cutting a long elastic body (e.g., one formed by extrusion molding) to a predetermined length, making it possible to easily form the elastic member.

[0065] In the cushioning member of Feature 6, the elastic member is columnar in shape, protruding from the opposing surfaces of the first support plate and the second support plate, which makes it possible to easily arrange the elastic member.

[0066] In the cushioning material of Feature 7, the first and second elastic members become thicker as they approach the fixing surfaces to the first and second support plates. This makes it possible to prevent the first and second elastic members from buckling when they are compressed and deformed between the first and second support plates.

[0067] Feature 9 makes it possible to easily integrally mold a first elastic member made of rubber onto the first support plate, and also to easily integrally mold a second elastic member made of rubber onto the second support plate.

[0068] While this specification and drawings disclose specific examples of the technology included in the claims, the technology described in the claims is not limited to these specific examples, but also includes various modifications and changes to these examples, as well as parts of the examples taken individually. [Explanation of symbols]

[0069] 10 Cushioning material 11 Support plate 11A First support plate 11B Second support plate 11M Opposing side 20 Elastic members 20A First elastic member 20B Second elastic member 20M Rubber Material 30 Opposing members 30A First opposing member 30B Second opposing member 40 Retaining member 40A First Film 40B Second Film 50 Battery Modules 51 battery cells 72A First Rubber Molding Die 72B Second Rubber Molding Die 72H 1st forming hole 72U 2nd molding hole

Claims

1. A cushioning material that is placed between battery cells, The first support plate and the second support plate are located opposite each other in the direction in which the battery cells are facing each other. The system comprises a plurality of elastic members that are compressible and deformable when sandwiched between the first support plate and the second support plate, Each of the aforementioned multiple elastic members is fixed to only one of the first support plate and the second support plate. The plurality of elastic members are cushion members arranged in positions that do not overlap each other in the opposing directions.

2. The cushion member according to claim 1, wherein the plurality of elastic members include a first elastic member fixed only to the first support plate and a second elastic member fixed only to the second support plate.

3. The first support plate and the second support plate are both made of metal. The cushion member according to claim 1, wherein the plurality of elastic members are made of non-foamed rubber.

4. The cushioning member according to claim 1, further comprising a holding member for holding the first support plate and the second support plate in an opposing state.

5. The cushion member according to claim 1, wherein the plurality of elastic members protrude from the opposing surfaces of the first support plate and the second support plate, and have a protruding structure that extends along the opposing surfaces.

6. The cushion member according to claim 1, wherein the plurality of elastic members are columnar in shape and protrude from the opposing surfaces of the first support plate and the second support plate.

7. A battery module in which a cushioning member according to any one of claims 1 to 6 is provided between battery cells.

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