Cell housing material

Abstract

To provide a cell storage member that can stably ensure the electrical and heat insulating properties of inter-cell separators despite deformation of cells.SOLUTION: A cell storage member 1 stores a laminate 8 of a plurality of cells 80 for a secondary battery. The cell storage member 1 comprises: a housing 2 that has an internal space 20 in which the laminate 8 is stored; inter-cell separators 3 that are each arranged in the internal space 20, are interposed between an arbitrary pair of cells 80 adjacent to each other in a lamination direction, and have electrical and heat insulating properties; and elastic members 4 that are each arranged on the inter-cell separator 3, are in elastic contact with an adjacent cell 80 in the laminate direction, and are easily elastically deformed following the deformation of the cell 80 rather than the inter-cell separator 3.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a cell housing member for use in, for example, an in-vehicle battery module. [Background technology]

[0002] Patent Document 1 discloses a power supply device used as a drive source for hybrid vehicles, electric vehicles, and the like. The power supply device includes a pair of end plates, a pair of fastening members, a plurality of secondary battery cells, and a plurality of separators. The pair of end plates and the pair of fastening members are combined to form a rectangular frame. The plurality of secondary battery cells and the plurality of separators are housed inside the frame. The secondary battery cells and the separators are stacked alternately. That is, a separator made of a flexible material is interposed between a pair of secondary battery cells adjacent in the stacking direction.

[0003] The separator has insulating properties in order to ensure insulation between a pair of adjacent secondary battery cells and prevent short circuits. The separator also has thermal insulation properties in order to prevent heat transfer between a pair of adjacent secondary battery cells and prevent a chain reaction of thermal runaway. The separator also has flexibility in order to absorb deformation (expansion, contraction) of the secondary battery cells. In this way, the separator has insulating properties, thermal insulation properties, and flexibility. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2018 / 207608 Brochure Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the case of the power supply device described in the document, the insulating and heat insulating properties of the separator are easily changed due to deformation of the secondary battery cell. For example, when a secondary battery cell expands, the separator adjacent to the secondary battery cell elastically contracts accordingly. This contraction allows the separator to absorb the expansion of the secondary battery cell. However, when the separator contracts, the distance between a pair of adjacent secondary battery cells sandwiching the separator becomes shorter accordingly.

[0006] Here, as described above, the separator is not only flexible but also insulating and thermally insulating. Therefore, when the separator shrinks, the insulating distance and heat transfer distance between a pair of adjacent secondary battery cells become shorter. Therefore, the insulating and thermal insulating properties decrease. In this way, in the case of the power supply device of the same document, the insulating and thermal insulating properties of the separator are likely to change with the deformation of the secondary battery cells. Therefore, the present disclosure aims to provide a cell housing member that can stably ensure the insulating and thermal insulating properties of the inter-cell separator regardless of the deformation of the cells. [Means for solving the problem]

[0007] (1) In order to solve the above problems, the cell housing member of the present disclosure is a cell housing member in which a stack of multiple cells for a secondary battery is housed, and is characterized in that it comprises: a housing having an internal space in which the stack is housed, with the extension direction of the stack being the stacking direction; an inter-cell separator having insulating and thermal insulation properties, disposed in the internal space and interposed between any pair of the cells adjacent to each other in the stacking direction; and an elastic member disposed in the inter-cell separator, elastically contacting the adjacent cell in the stacking direction, and more easily elastically deforming in response to deformation of the cell than the inter-cell separator.

[0008] According to the cell housing member of the present disclosure, an elastic member separate from the inter-cell separator is disposed in the inter-cell separator. The inter-cell separator has insulating and heat insulating properties. On the other hand, the elastic member has elasticity that allows it to elastically deform in response to the deformation of the cells. In this manner, the inter-cell separator and the elastic member each share a function. Therefore, even if the elastic member elastically deforms in response to the deformation of the cells, the deformation of the inter-cell separator can be suppressed. Therefore, even if the elastic member elastically deforms, it is possible to suppress changes in the thickness of the inter-cell separator in the stacking direction, that is, the insulation distance and the heat transfer distance. In this manner, according to the cell housing member of the present disclosure, the insulation and heat insulating properties of the inter-cell separator can be stably ensured regardless of the deformation of the cells.

[0009] (2) In the above configuration, the cell may be a rectangular cell. In any of the above configurations, the cell housing member may be used in an in-vehicle battery module.

[0010] (3) In any of the above configurations, the elastic member may be arranged on the inside of the inter-cell separator when viewed from the stacking direction. When the cells expand in the stacking direction, the elastic member contracts in the stacking direction. Depending on the type of elastic member, the elastic member may bulge outward (in a direction intersecting the stacking direction) when viewed from the stacking direction in response to the contraction. With this configuration, the elastic member can be prevented from bulging outward from the inter-cell separator.

[0011] (4) In any of the above configurations, a direction intersecting the stacking direction may be defined as a juxtaposition direction, and a plurality of the laminates may be accommodated in the internal space and arranged in the juxtaposition direction. In this configuration, an interlayer separator having insulating and thermal insulation properties may be disposed in the internal space and interposed between any pair of adjacent laminates. With this configuration, it is possible to stably ensure insulating and thermal insulation properties between any pair of adjacent laminates.

[0012] (5) In any of the above configurations, the inter-cell separator may have an inter-cell separator-side slit. In any of the above configurations (including an interlayer separator), the interlayer separator may have an interlayer separator-side slit.

[0013] In a configuration in which the inter-cell separator has an inter-cell separator-side slit and the interlayer separator has an interlayer separator-side slit, the inter-cell separator and the interlayer separator may be assembled in a cross shape by fitting the inter-cell separator-side slit and the interlayer separator-side slit into each other. With this configuration, the inter-cell separator and the interlayer separator can be assembled simply and reliably. Also, the inter-cell separator and the interlayer separator can be positioned simply and reliably.

[0014] (6) In any of the above configurations, the housing may be configured as a single unit. With this configuration, the number of parts can be reduced compared to when the housing is a composite of multiple members (for example, the pair of end plates and the pair of fastening members in the power supply device of Patent Document 1).

[0015] In this configuration, the direction intersecting a plane including the stacking direction and the juxtaposition direction may be defined as a cell insertion / removal direction, and the housing may have a cylindrical wall portion extending in the cell insertion / removal direction, a bottom wall portion sealing one end of the cylindrical wall portion in the cell insertion / removal direction, and an opening portion opened at the other end of the cylindrical wall portion in the cell insertion / removal direction. According to this configuration, the housing has a bottomed cylindrical shape (bottomed box shape). Therefore, cells, inter-cell separators, elastic members, etc. can be easily inserted and removed from the internal space through the opening portion.

[0016] (7) In any of the above configurations (configurations including a cylindrical wall portion), the cylindrical wall portion may have a pair of first walls extending in the stacking direction and spaced a predetermined distance apart from each other in the juxtaposition direction, and an inner surface of the first walls may have a first guide groove into which at least an outer edge of the inter-cell separator and the elastic member is inserted. With this configuration, the inter-cell separator can be easily and reliably assembled to the first wall, i.e., the housing. Furthermore, the inter-cell separator can be easily and reliably positioned with respect to the housing.

[0017] (8) In any of the above configurations (configurations including a cylindrical wall portion and an interlayer separator), the cylindrical wall portion may have a pair of second walls extending in the juxtaposition direction and spaced a predetermined distance apart in the stacking direction, and the inner surface of the second wall may have a second guide groove into which the outer edge of the interlayer separator is inserted. With this configuration, the interlayer separator can be easily and reliably assembled to the second wall, i.e., the housing. Also, the interlayer separator can be easily and reliably positioned with respect to the housing.

[0018] (9) Any of the above configurations (configurations including a bottom wall portion) may further include a cooling member disposed on the bottom wall portion and configured to cool the cells. With this configuration, the cells can be cooled. Effect of the Invention

[0019] According to the cell housing member of the present disclosure, the electrical insulation and heat insulating properties of the inter-cell separators can be stably ensured regardless of deformation of the cells. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a perspective view of an on-board battery module including a cell housing member according to a first embodiment. [Diagram 2] FIG. 2 is an exploded perspective view of the vehicle-mounted battery module. [Diagram 3] FIG. 3 is an exploded perspective view of the cell housing member. [Figure 4] FIG. 4 is an exploded perspective view of an inter-cell separator and an interlayer separator of the cell housing member. [Diagram 5] FIG. 5 is a top view of the vehicle-mounted battery module. [Figure 6] FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII of FIG. [Figure 8] FIG. 8 is an enlarged view of the area VIII in FIG. [Figure 9] FIG. 9 is a cross-sectional view in the stacking direction of a cell housing member of the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, an embodiment of the cell housing member of the present disclosure will be described. In the following figures, the front-rear direction corresponds to the "stacking direction" of the present disclosure, the left-right direction corresponds to the "juxtaposition direction" of the present disclosure, and the up-down direction corresponds to the "cell insertion / removal direction" of the present disclosure.

[0022] First Embodiment FIG. 1 shows a perspective view of an on-vehicle battery module including a cell housing member of the present embodiment. FIG. 2 shows an exploded perspective view of the on-vehicle battery module. FIG. 3 shows an exploded perspective view of the cell housing member. FIG. 4 shows an exploded perspective view of an inter-cell separator and an interlayer separator of the cell housing member. FIG. 5 shows a top view of the on-vehicle battery module. FIG. 6 shows a cross-sectional view taken along the line VI-VI in FIG. 5. FIG. 7 shows a cross-sectional view taken along the line VII-VII in FIG. 5. FIG. 8 shows an enlarged view of the area within the frame VIII in FIG. 7.

[0023] [Configuration of cell housing material] First, the configuration of the cell housing member of this embodiment will be described. As shown in Figures 1 and 2, the cell housing member 1 of this embodiment is incorporated into an on-board battery module 9. The cell housing member 1 houses two stacks 8.

[0024] (Laminate 8) The two laminates 8 are arranged side by side in the left-right direction. The laminates 8 extend in the front-rear direction. As shown in Figs. 2 and 5, the laminate 8 includes a plurality of cells 80 for a lithium ion secondary battery. The plurality of cells 80 are stacked in the front-rear direction. When viewed from above, the cells 80 have a rectangular shape (flat shape) that is long in the left-right direction. In other words, the cells 80 are rectangular cells. Terminals (positive electrode terminal, negative electrode terminal) 800 and a gas exhaust valve (not shown) are disposed on the upper surface of the cell 80. The terminals 800 of the cells 80 adjacent to each other in the front-rear direction are electrically connected (connected in series or parallel) by a bus bar (not shown).

[0025] (Cell housing member 1) The cell housing member 1 includes a housing 2 , a plurality of inter-cell separators 3 , a plurality of elastic members 4 , an interlayer separator 5 , and two cooling members 6 .

[0026] (Case 2) As shown in Fig. 3, the housing 2 is a one-piece body made of resin. The housing 2 has a bottomed cylindrical shape (a rectangular parallelepiped box shape that opens upward). The housing 2 includes an internal space 20, a cylindrical wall portion 21, a bottom wall portion 22, and an opening portion 23. The internal space 20 is defined inside the housing 2. Two laminates 8 are housed in the internal space 20.

[0027] The cylindrical wall portion 21 has a rectangular cylindrical shape extending in the vertical direction (the cylindrical axis faces the vertical direction). When viewed from above, the cylindrical wall portion 21 has a rectangular frame shape that is long in the front-rear direction. The cylindrical wall portion 21 has two first walls 210 and two second walls 211.

[0028] The two first walls 210 are arranged side by side at a predetermined interval in the left-right direction. The first wall 210 has a rectangular plate shape that is long in the front-rear direction. A plurality of first guide grooves 210a are recessed in the inner surface of the first wall 210. The plurality of first guide grooves 210a are arranged side by side in the front-rear direction. The first guide grooves 210a extend in the up-down direction. Both left and right edges (outer edges) of an inter-cell separator 3 described later are inserted into the pair of left and right first guide grooves 210a (more specifically, the pair of first guide grooves 210a that are located at the same position in the front-rear direction among the plurality of first guide grooves 210a of the left first wall 210 and the plurality of first guide grooves 210a of the right first wall 210).

[0029] The two second walls 211 are arranged side by side at a predetermined distance in the front-rear direction. The second wall 211 has a rectangular plate shape that is long in the left-right direction. A second guide groove 211a is recessed in the center of the inner surface of the second wall 211 in the left-right direction. The second guide groove 211a extends in the up-down direction. Front and rear edges (outer edges) of an interlayer separator 5 (described later) are inserted into the pair of front and rear second guide grooves 211a.

[0030] The bottom wall portion 22 seals the lower end (one end in the cell insertion / removal direction) of the cylindrical wall portion 21. The bottom wall portion 22 has a rectangular plate shape that is long in the front-rear direction. Two mounting openings 220 are formed in the bottom wall portion 22. When viewed from above, the two mounting openings 220 are arranged spaced apart in the left-right direction, sandwiching the second guide groove 211a therebetween. The mounting openings 220 penetrate the bottom wall portion 22 in the up-down direction and the front-rear direction.

[0031] The opening 23 is provided at the upper end (the other end in the cell insertion / removal direction) of the cylindrical wall portion 21. The laminate 8 (cells 80), the inter-cell separator 3 with the elastic member 4, and the interlayer separator 5, which will be described later, are inserted into the internal space 20 or removed from the internal space 20 through the opening 23.

[0032] (Inter-cell separator 3) As shown in Figs. 2 and 3, a plurality of inter-cell separators 3 are disposed in the internal space 20. As shown in Figs. 5, 7 and 8, the inter-cell separators 3 are interposed between a pair of cells 80 adjacent in the front-rear direction in the laminate 8. The inter-cell separators 3 are made of resin and have a plate shape that is long in the left-right direction. The inter-cell separators 3 extend over the entire length of the internal space 20 in the left-right direction. The inter-cell separators 3 have insulating and heat-insulating properties. As shown in Figs. 4 and 6, the inter-cell separator 3 has an inter-cell separator-side slit 30 and a pair of left and right cell spacing wall portions 31.

[0033] The inter-cell separator-side slit 30 is disposed between (at the center in the left-right direction) a pair of left and right cell spacing wall portions 31. The inter-cell separator-side slit 30 opens at the lower edge of the inter-cell separator 3. The inter-cell separator-side slit 30 extends to the center of the inter-cell separator 3 in the up-down direction.

[0034] (Elastic member 4) As shown in Figs. 4, 6, 7 and 8, the elastic members 4 are each disposed on the front surface (one surface) of the cell partition wall portion 31 of the inter-cell separator 3. The elastic members 4 are separate from the inter-cell separator 3 and are fixed to the inter-cell separator 3. When viewed from the front side, the elastic members 4 are disposed on the inner side (inner side in the left-right direction and inner side in the up-down direction) of the cell partition wall portion 31. The elastic members 4 are made of foamed rubber and have a plate shape. The elastic members 4 have elasticity. The elastic members 4 are in elastic contact with the cells 80 in front of them due to their elastic restoring force. That is, in a state in which the laminate 8 is accommodated in the cell accommodating member 1, a predetermined elastic energy is accumulated in the elastic members 4. The elastic members 4 are more flexible than the cells 80 and the cell partition wall portion 31. The elastic members 4 are more likely to elastically deform in response to the deformation of the cells 80 than the inter-cell separator 3 (cell partition wall portion 31).

[0035] (Interlayer separator 5) As shown in Figs. 2 and 3, the interlayer separator 5 is disposed in the internal space 20. As shown in Fig. 5, the interlayer separator 5 is interposed between a pair of left and right laminates 8. The interlayer separator 5 is made of resin and has a plate shape that is long in the front-rear direction. The interlayer separator 5 extends over the entire length of the internal space 20 in the front-rear direction. The interlayer separator 5 has insulating and heat-insulating properties. As shown in Fig. 4, the interlayer separator 5 has a plurality of interlayer separator-side slits 50. The plurality of interlayer separator-side slits 50 are arranged side by side in the front-rear direction at a predetermined interval. The interlayer separator-side slits 50 open at the upper edge of the interlayer separator 5. The interlayer separator-side slits 50 extend to the center of the interlayer separator 5 in the up-down direction.

[0036] As shown in Figures 3 and 4, the intercell separator 3 and the interlayer separator 5 are assembled in a cross shape by fitting (interlocking) the intercell separator-side slits 30 and the interlayer separator-side slits 50 with each other from above and below. As shown in Figures 2 and 5, the intercell separators 3 and the interlayer separators 5 assembled in a cross shape partition the internal space 20 into a plurality of cell chambers 200 aligned in the front-rear and left-right directions. Any one of the cell chambers 200 is isolated from the adjacent cell chambers 200 in the front-rear direction and from the adjacent cell chambers 200 in the left-right direction. Each of the plurality of cell chambers 200 contains a cell 80.

[0037] (Cooling member 6) As shown in FIG. 3, the two cooling members 6 are each disposed in the mounting opening 220 of the bottom wall portion 22. The cooling member 6 is made of resin and has a rectangular plate shape that is long in the front-rear direction. As shown in FIGS. 6, 7, and 8, the upper surface of the cooling member 6 abuts against the lower surface of the cell 80. A plurality of flow paths 60 are formed inside the cooling member 6. The plurality of flow paths 60 are aligned in the left-right direction. The flow paths 60 penetrate the cooling member 6 in the front-rear direction. A cooling liquid C flows through the flow paths 60. The cooling member 6 cools the cell 80 by the cooling liquid C. As shown in FIG. 7, the flow paths 60 are connected to a cooling circuit 7 outside the vehicle-mounted battery module 9. The cooling circuit 7 includes a radiator 70 and a pump 71. The cooling liquid C flowing out of the flow paths 60 is cooled by the radiator 70. The cooling liquid C flowing out of the radiator 70 is pumped by the pump 71 and flows into the flow paths 60.

[0038] [How to assemble the cell housing components] Next, a method for assembling the cell housing member of this embodiment will be described. As shown in Fig. 3, the cooling member 6 is fixed in advance to the mounting opening 220 of the bottom wall portion 22 of the housing 2. In addition, the elastic member 4 is fixed in advance to the inter-cell separator 3.

[0039] First, the interlayer separator 5 is inserted into the internal space 20 of the housing 2. Specifically, both front and rear edges of the interlayer separator 5 are inserted into the second guide groove 211a. Next, a plurality of intercell separators 3 are inserted into the internal space 20 of the housing 2. Specifically, both left and right edges of the intercell separator 3 are inserted into the first guide groove 210a. Additionally, the intercell separator side slit 30 and the interlayer separator side slit 50 are fitted together. In this manner, the cell housing member 1 is assembled. Thereafter, a plurality of cells 80 are inserted into the cell chamber 200, as shown in FIG. 2.

[0040] [Effects] Next, the effects of the cell housing member of this embodiment will be described. As shown in Fig. 8, an elastic member 4 separate from the inter-cell separator 3 is disposed on the inter-cell separator 3. The inter-cell separator 3 has insulating and heat-insulating properties. On the other hand, the elastic member 4 is more flexible than the cells 80 and the inter-cell separator 3. The elastic member 4 also has elasticity that allows it to elastically deform in response to deformation of the cells 80. In this way, the inter-cell separator 3 and the elastic member 4 each have their own functions.

[0041] For example, as shown by the dashed dotted line L in Fig. 8, the cells 80 may expand in the front-rear direction due to charging, deterioration, etc. In this case, the elastic member 4 can contract in the front-rear direction by an amount corresponding to the expansion of the cells 80. This contraction allows the elastic member 4 to absorb the expansion of the cells 80. Furthermore, because the expansion of the cells 80 is absorbed by the elastic member 4, the thickness T in the front-rear direction of the inter-cell separator 3 (cell spacing wall portion 31) does not change even if the cells 80 expand. This makes it possible to prevent the insulation distance and heat transfer distance from becoming shorter.

[0042] Conversely, when the cells 80 contract in the front-rear direction, the elastic members 4 can expand in the front-rear direction by the amount of contraction of the cells 80 due to their own elastic restoring force. This expansion allows the elastic members 4 to absorb the contraction of the cells 80. Furthermore, because the contraction of the cells 80 is absorbed by the elastic members 4, the thickness T in the front-rear direction of the inter-cell separators 3 (cell spacing wall portions 31) does not change even if the cells 80 contract. This makes it possible to prevent the insulation distance and heat transfer distance from becoming longer.

[0043] In this way, the cell housing member 1 of the present embodiment can suppress deformation of the inter-cell separator 3 even if the elastic member 4 elastically deforms in response to deformation of the cells 80. Therefore, even if the elastic member 4 elastically deforms, it is possible to suppress changes in the thickness T in the front-to-rear direction of the inter-cell separator 3, i.e., the insulation distance and heat transfer distance. In this way, the cell housing member 1 of the present embodiment can stably ensure the insulation and heat insulation properties of the inter-cell separator 3 regardless of deformation of the cells 80.

[0044] The elastic member 4 is made of foamed rubber. Therefore, compared to elastic members 4 made of fibers (such as knitted fabrics and woven fabrics, which are also included in the concept of "elastic member" in the present disclosure), the elastic member 4 is less susceptible to plastic deformation and viscous deformation, and has a large elastic restoring force. Therefore, the binding force in the front-rear direction for the laminate 8 is less likely to decrease.

[0045] The elastic member 4 is deformable in response to deformation of the outer surface of the cell 80. Therefore, even if only a portion of the cell 80 expands, the elastic member 4 can absorb the deformation. Therefore, a load is unlikely to be applied locally to the inter-cell separator 3 or the cell 80.

[0046] 1 and 2, two laminates 8 arranged side by side in the left-right direction are housed in the internal space 20. An interlayer separator 5 having insulating and heat-insulating properties is disposed between the two laminates 8. Therefore, insulating and heat-insulating properties can be ensured between the two adjacent laminates 8.

[0047] 1 and 2, the cell 80 is a rectangular cell. The internal space 20 has a rectangular parallelepiped shape. Therefore, a plurality of cells 80 can be densely arranged in the internal space 20. This improves space efficiency.

[0048] As shown in FIG. 4, the inter-cell separator 3 has an inter-cell separator side slit 30. The inter-layer separator 5 has an inter-layer separator side slit 50. The inter-cell separator side slit 30 and the inter-layer separator side slit 50 are fitted together, so that the inter-cell separator 3 and the inter-layer separator 5 are assembled in a cross shape. Therefore, the inter-cell separator 3 and the inter-layer separator 5 can be assembled simply and reliably. In addition, the inter-cell separator 3 and the inter-layer separator 5 can be positioned simply and reliably. In addition, as shown in FIG. 4, the upper end bottom of the inter-cell separator side slit 30 and the lower end bottom of the inter-layer separator side slit 50 are in contact with each other. Therefore, the inter-cell separator 3 and the inter-layer separator 5 can be assembled without any gaps. In addition, since there is no gap between the inter-cell separator 3 and the inter-layer separator 5, heat transfer between the cells 80 through the gaps can be suppressed.

[0049] As shown in Fig. 6, both left and right edges of the inter-cell separator 3 are inserted into a pair of left and right first guide grooves 210a. This allows the inter-cell separator 3 to be easily and reliably attached to the first wall 210, i.e., the housing 2. Furthermore, the inter-cell separator 3 can be easily and reliably positioned with respect to the housing 2. Furthermore, since there is no gap between the first guide grooves 210a and the inter-cell separator 3, heat transfer between the cells 80 through the gap can be suppressed.

[0050] 5, both front and rear edges of interlayer separator 5 are inserted into a pair of front and rear second guide grooves 211a. This allows interlayer separator 5 to be easily and reliably attached to second wall 211, i.e., housing 2. Furthermore, interlayer separator 5 can be easily and reliably positioned with respect to housing 2. Furthermore, since there is no gap between second guide groove 211a and interlayer separator 5, heat transfer between cells 80 through the gap can be suppressed.

[0051] The inter-cell separator 3 is firmly fixed by the casing 2 (first guide groove 210a) and the interlayer separator 5 (interlayer separator side slit 50). Therefore, the rigidity of the inter-cell separator 3 is high. In addition, the interlayer separator 5 is firmly fixed by the casing 2 (second guide groove 211a) and the inter-cell separator 3 (inter-cell separator side slit 30). Therefore, the rigidity of the interlayer separator 5 is high. In addition, the casing 2 is supported from the internal space 20 side by the inter-cell separator 3 and the interlayer separator 5 assembled in a cross shape. Therefore, the rigidity of the casing 2 is high. In addition, the multiple cell chambers 200 are isolated from each other by the inter-cell separator 3 and the interlayer separator 5 assembled in a cross shape. Therefore, heat transfer between the cells 80 can be suppressed.

[0052] When the cells 80 expand in the front-to-rear direction, the elastic members 4 contract in the stacking direction. In response to this contraction, the elastic members 4 bulge outward (in the up-down and left-right directions in FIG. 6) when viewed from the front. In this regard, the elastic members 4 are disposed inside the inter-cell separators 3 when viewed from the front. This makes it possible to prevent the elastic members 4 from bulging outward from the inter-cell separators 3.

[0053] The inter-cell separator 3 has insulating and heat-insulating properties. Therefore, the number of parts of the cell housing member 1 can be reduced compared to a case where an insulating separator and a heat-insulating separator are disposed independently. Also, the space required for the cell housing member 1 can be reduced. Furthermore, since the inter-cell separator 3 has insulating properties, the exterior material (case) of the cell 80 does not need to have insulating properties.

[0054] The inter-cell separator 3 has the function of dividing the cell chamber 200, in addition to the insulating and heat-insulating properties. That is, it has the function of positioning the cells 80. Therefore, the number of parts of the cell housing member 1 can be reduced compared to the case where a member for positioning the cells 80 is arranged separately from the inter-cell separator 3. Also, the space required for the cell housing member 1 can be saved.

[0055] As shown in Fig. 3, the housing 2 is a one-piece body. Therefore, the number of parts can be reduced compared to when the housing 2 is a composite of a plurality of members. The housing 2 has a bottomed cylindrical shape (bottomed box shape). Therefore, the cells 80, the inter-cell separators 3 with the elastic members 4, and the interlayer separators 5 can be easily inserted into and removed from the internal space 20 through the openings 23.

[0056] As shown in Figs. 6, 7, and 8, two cooling members 6 are arranged on the bottom wall 22. As shown by arrow Y in Fig. 8, the heat of the cells 80 is transferred to the cooling liquid C through the wall of the cooling member 6. Therefore, the cells 80 can be cooled. In addition, the cooling member 6 and the cells 80 are in direct contact with each other without any other member. Therefore, the cells 80 can be effectively cooled. In addition, an inter-cell separator 3 and an inter-layer separator 5 are arranged around the cells 80. Both the inter-cell separator 3 and the inter-layer separator 5 have thermal insulation properties. Therefore, the heat of the cells 80 can be preferentially guided to the cooling member 6. Note that an elastic body with high thermal conductivity may be interposed between the cooling member 6 and the cells 80. In this case, for example, it is desirable that the thermal conductivity of the elastic body at 25°C is 3 W / (m·K) or more.

[0057] As shown in Fig. 3, the cell housing member 1 of this embodiment can be assembled simply by inserting the interlayer separator 5 and the inter-cell separator 3 with the elastic member 4 into the housing 2. This simplifies the assembly work of the cell housing member 1. Furthermore, the vehicle-mounted battery module 9 can be assembled simply by inserting the cells 80 into the cell chambers 200 of the assembled cell housing member 1. This simplifies the assembly work of the vehicle-mounted battery module 9.

[0058] Second Embodiment The cell housing member of this embodiment differs from the cell housing member of the first embodiment in that elastic members are disposed on both front and rear sides of the inter-cell separator. Here, only the difference will be described.

[0059] FIG. 9 shows a cross-sectional view of the cell housing member of this embodiment in the stacking direction (front-rear direction). The same reference numerals are used to indicate parts corresponding to those in FIG. 7. As shown in FIG. 9, an elastic member 4 is disposed on both front-rear sides of the inter-cell separator 3 (cell spacing wall portion 31). The cell housing member of this embodiment and the cell housing member of the first embodiment have similar effects with respect to parts having a common configuration. According to the cell housing member 1 of this embodiment, both front-rear sides of the cells 80 (excluding the cells 80 at both ends of the stack 8 in the front-rear direction) are in elastic contact with the elastic member 4. This makes it possible to absorb deformation of the cells 80 on both front-rear sides.

[0060] <Other> The embodiment of the cell housing member of the present disclosure has been described above. However, the embodiment is not particularly limited to the above embodiment. It is also possible to carry out the present disclosure in various modified and improved forms that can be achieved by those skilled in the art.

[0061] [About placement and configuration] In the above embodiment, the stacking direction (front-rear direction), the juxtaposition direction (left-right direction), and the cell insertion / removal direction (up-down direction) are set to be perpendicular to each other, but the intersection angle of these directions is not particularly limited. Furthermore, the orientation of the stacking direction, the juxtaposition direction, and the cell insertion / removal direction is not particularly limited. For example, the stacking direction may be the up-down direction. The stacking direction may be the direction in which deformation is greatest in the cell 80. When the cell 80 is a rectangular cell or a laminated cell, the stacking direction may be aligned with the stacking direction of the positive electrode layer, the separator, and the negative electrode layer inside the cell 80.

[0062] There is no particular limit to the number of inter-cell separators 3 arranged. There may be either a single or multiple. This may be increased or decreased depending on the number of cells 80 constituting the laminate 8. There is no particular limit to the number of cell spacing wall portions 31 arranged in the inter-cell separator 3. There may be either a single or multiple. This may be increased or decreased depending on the number of cells 80 arranged in the juxtaposition direction (i.e., the number of laminates 8 arranged). There is no particular limit to the number of interlayer separators 5 arranged. There may be either a single or multiple. This may be increased or decreased depending on the number of laminates 8 arranged.

[0063] The orientation of the inter-cell separator side slit 30 and the inter-layer separator side slit 50 is not particularly limited. The inter-cell separator side slit 30 and the inter-layer separator side slit 50 may face each other in the cell insertion / removal direction so that they can be fitted together. For example, the inter-layer separator side slit 50 may face one end side (lower side) in the cell insertion / removal direction, and the inter-cell separator side slit 30 may face the other end side (upper side) in the cell insertion / removal direction. In this case, when assembling the cell housing member 1, the inter-cell separator 3 may be inserted first into the internal space 20, and then the inter-layer separator 5 may be inserted into the internal space 20. Regardless of the orientation of the inter-cell separator side slit 30 and the inter-layer separator side slit 50, the inter-cell separator 3 and the inter-layer separator 5 may be assembled in advance outside the housing 2, and then the assembled product may be inserted into the internal space 20.

[0064] The method of assembling the inter-cell separator 3 and the inter-layer separator 5 is not particularly limited. The inter-cell separator 3 and the inter-layer separator 5 may be assembled using fasteners (bolts, screws, clips, etc.). The inter-cell separator 3 and the inter-layer separator 5 may be assembled by adhesion (adhesive, double-sided tape, etc.), pressure bonding, welding, etc. An integrated lattice-shaped separator in which the inter-cell separator 3 and the inter-layer separator 5 are integrally formed may be used. The housing 2 and at least one of the inter-cell separator 3 and the inter-layer separator 5 may be integrated.

[0065] The number of elastic members 4 arranged on the inter-cell separator 3 is not particularly limited. The elastic members 4 may be arranged on at least one of both sides of the inter-cell separator 3 in the stacking direction. The type of the multiple inter-cell separators 3 is not particularly limited. At least one of the multiple inter-cell separators 3 may be an inter-cell separator 3 with an elastic member 4. The size of the elastic member 4 on the inter-cell separator 3 is not particularly limited. For example, the elastic member 4 may be arranged on the entirety of at least one of both sides of the inter-cell separator 3 in the stacking direction. The method of fixing the elastic member 4 to the inter-cell separator 3 is not particularly limited. The elastic member 4 may be fixed to the inter-cell separator 3 by adhesion (adhesive, double-sided tape, etc.), pressure bonding, welding, etc. The elastic member 4 may be arranged on the inner surface of the second wall 211 and elastically contacted with the cells 80 at both ends of the stacking direction of the laminate 8. The elastic member 4 may be arranged on the interlayer separator 5.

[0066] When inserting both left and right edges of the inter-cell separator 3 into the first guide groove 210a, both left and right edges of the elastic member 4 may also be inserted into the first guide groove 210a. In this way, the elastic member 4 is compressed between the groove side surface of the first guide groove 210a and the inter-cell separator 3. This makes it difficult for the inter-cell separator 3 to fall out of the first guide groove 210a. In this way, of the inter-cell separator 3 and the elastic member 4, it is sufficient that at least the inter-cell separator 3 is inserted into the first guide groove 210a.

[0067] The shape of the cylindrical wall portion 21 of the housing 2 is not particularly limited. It may be a square tube (square tube, hexagonal tube, octagonal tube, etc.), a cylindrical shape (true cylindrical shape, elliptical cylindrical shape, etc.), etc. When viewed from the cell insertion / removal direction, the cylindrical wall portion may be an endless ring shape. The shape of the bottom wall portion 22 is not particularly limited. It is sufficient that one end of the cylindrical wall portion 21 in the cell insertion / removal direction is sealed. The bottom wall portion 22 does not have to be provided. In this case, it is sufficient that one end of the cylindrical wall portion 21 in the cell insertion / removal direction is sealed with the cooling member 6. It is not necessary for cells 80 to be provided in all of the cell chambers 200.

[0068] The number of cooling members 6 arranged is not limited. The number of cooling members 6 arranged and the number of stacks 8 arranged may be the same or different. For example, a single cooling member 6 may be arranged for two stacks 8. The number of flow paths 60 arranged is not limited. The type of coolant is not limited. For example, when the cell accommodating member 1 is used in an in-vehicle battery module 9, the coolant may be a vehicle coolant. The type of cooling member 6 is not particularly limited. The cooling member 6 may be equipped with a heat pipe or a fan. The cooling member 6 does not need to be equipped with a flow path 60.

[0069] The type of cell 80 is not particularly limited. It may be a rectangular cell, a cylindrical cell, a laminated cell, etc. The type of secondary battery is not particularly limited. It may be a lithium ion secondary battery, a lithium ion polymer secondary battery, a sodium ion secondary battery, a nickel hydrogen secondary battery, etc.

[0070] The use of the cell housing member 1, i.e., the battery module, is not particularly limited. For example, it may be used in hybrid cars, electric cars, etc. It may also be used in electrically assisted bicycles, mobile phones, power tools, notebook computers, etc.

[0071] [About materials] There is no particular limitation on the material of the cooling member 6. For example, it may be a resin such as PP (polypropylene), or a metal such as aluminum or an aluminum alloy.

[0072] The material of the elastic member 4 is not particularly limited. For example, it may be a foam of elastomer (including rubber) such as EPDM (ethylene propylene diene rubber), silicone, butyl rubber, acrylic rubber, etc. The form of the elastic member 4 is not particularly limited. It may be a foam, a woven fabric, a nonwoven fabric, a hollow body, a solid body, etc.

[0073] The material of the housing 2 is not particularly limited. For example, it may be a resin such as PP, or a metal such as steel, aluminum, or an aluminum alloy. The materials of the inter-cell separator 3 and the interlayer separator 5 are not particularly limited. For example, it may be a resin such as epoxy, or ceramics.

[0074] There are no particular limitations on the insulating properties of the inter-cell separator 3. It is sufficient that the insulation between adjacent cells 80 sandwiching the inter-cell separator 3 is ensured. For example, it is desirable that the electrical resistivity at 25° C. is 10E+10 Ω·m or more. The same applies to the interlayer separator 5.

[0075] There are no particular limitations on the heat insulating properties of the inter-cell separator 3. It is sufficient that heat insulation between adjacent cells 80 sandwiching the inter-cell separator 3 is ensured. For example, it is desirable that the thermal conductivity at 25° C. is 0.1 W / (m K) or less. The same applies to the interlayer separator 5.

[0076] The following fireproof and insulating material may be used as at least one of the housing 2, the inter-cell separator 3, and the interlayer separator 5. The fireproof and insulating material contains cellulose fibers, inorganic fibers, flame-retardant inorganic particles, fire-resistant inorganic particles, and a binder resin.

[0077] Cellulosic fibers are fibers made from cellulose. Examples of cellulose fibers include vegetable fibers such as cotton and hemp, regenerated fibers such as rayon and Lyocell (registered trademark), and semi-synthetic fibers such as acetate.

[0078] In consideration of electrical insulation and flame retardancy, the inorganic fibers are preferably one or more selected from glass fibers, alumina fibers, and silica fibers. From the viewpoint of increasing the strength and fire resistance of the fireproof insulation component, it is preferable that the inorganic fibers are relatively thick and long. For example, the fiber diameter of the inorganic fibers is preferably 1 μm or more and 20 μm or less. In addition, the length of the inorganic fibers is preferably 13 mm or more and 25 mm or less. If the length is less than 13 mm, the effect of improving the strength is small, and if the length is more than 25 mm, the moldability may decrease.

[0079] Considering the balance between the retention power of the inorganic particles and the flame retardancy, it is desirable to set the mass content of the cellulose fibers to be equal to or less than the mass content of the inorganic fibers, i.e., the mass content of the cellulose fibers is desirably equal to or less than the mass content of the inorganic fibers.

[0080] Flame-retardant inorganic particles suppress combustion by decomposing themselves when heated. Examples of flame-retardant inorganic particles include particles of metal hydroxides and inorganic phosphorus-based flame retardants, which are known as inorganic flame retardants. Examples of metal hydroxides include aluminum hydroxide and magnesium hydroxide. Examples of inorganic phosphorus-based flame retardants include ammonium polyphosphate. Among these, inorganic phosphorus-based flame retardants are preferred because they form a non-combustible layer made of a carbonized coating when heated and have a high combustion suppression effect.

[0081] Fire-resistant inorganic particles are difficult to burn when heated, which contributes to improving the fire resistance of fire-resistant insulation materials. Examples of fire-resistant inorganic particles include particles of inorganic materials classified as "non-combustible materials" that meet three requirements under the Building Standards Act, such as not burning for 20 minutes after heating begins. For example, talc, mica, kaolinite, silica, alumina, etc. can be used.

[0082] The type of binder resin is not particularly limited as long as it can bind fibrous materials (including cellulose fibers and inorganic fibers) together and fibrous materials and inorganic particles together. The binder resin may be a thermoplastic resin or a thermosetting resin. When a thermoplastic resin is used, if its melting point is 200°C or less, it can be melted at a relatively low temperature, and is therefore easy to manufacture. When a thermosetting resin is used, it is highly effective in increasing the strength of the fireproof heat insulating member. Examples of the thermoplastic resin include polyvinyl alcohol, nylon resin, and fluororesin. Examples of the thermosetting resin include phenolic resin, epoxy resin, unsaturated polyester resin, and vinyl ester resin.

[0083] The content by mass of the organic matter (including cellulose fibers and binder resin) is desirably 5 times or less than the content by mass of the flame-retardant inorganic particles. In this way, the particle retention force of the cellulose fibers and the binding force of the binder resin can be secured while achieving the desired flame retardancy and heat insulation properties. From the viewpoint of increasing the retention force of the inorganic particles and the binding force between the inorganic particles and the fiber material, and between the fiber materials themselves, the content by mass of the organic matter is desirably 40% by mass or more when the entire fire-resistant insulation component is taken as 100% by mass. It is more preferable that the content by mass is 50% by mass or more.

[0084] From the viewpoint of forming a dense skeleton with the fiber material, increasing the retention of the inorganic particles, and thus increasing the strength of the fireproof insulation component, it is desirable that the total content of the flame-retardant inorganic particles, the fire-resistant inorganic particles, and the binder resin is 2 / 3 or less of the total content of the cellulose fibers and the inorganic fibers. Here, "2 / 3 or less" means that the total content of the flame-retardant inorganic particles, the fire-resistant inorganic particles, and the binder resin is 0.67 or less when divided by the total content of the cellulose fibers and the inorganic fibers. If the value is not divisible, the divided value is rounded off to two decimal places, and it is sufficient that the value is 0.67 or less.

[0085] The thickness of the fireproof insulation member (e.g., the wall thickness of the first wall 210 of the housing 2, the wall thickness of the second wall 211, the plate thickness of the inter-cell separator 3, and the plate thickness of the interlayer separator 5) is not particularly limited, but from the viewpoint of the capacity of accommodating the cells 80 in the internal space 20, it is desirable that the thickness is 5 mm or less. On the other hand, in consideration of the fire resistance, heat insulation, etc. of the fireproof insulation member, the thickness is desirably 1 mm or more. Furthermore, the fireproof insulation member may contain other components in addition to the cellulose fibers, inorganic fibers, flame-retardant inorganic particles, fire-resistant inorganic particles, and binder resin.

[0086] The above-mentioned fireproof and heat-insulating member can be manufactured by a pulp molding method. The pulp molding method includes a dispersion preparation step, an intermediate molding formation step, and a drying step. In the dispersion preparation step, cellulose fibers, inorganic fibers, flame-retardant inorganic particles, fire-resistant inorganic particles, and a binder resin are dispersed in water to prepare a dispersion. In the intermediate molding formation step, a mold is immersed in the prepared dispersion and the dispersion is sucked through the mold to form an intermediate molding on the surface of the mold. In the drying step, the intermediate molding is heated and dried to produce a molding.

[0087] The above-mentioned fireproof and heat-insulating member can be manufactured by a compression molding method. The compression molding method includes a slurry preparation step and a compression molding step. In the slurry preparation step, cellulose fibers, inorganic fibers, flame-retardant inorganic particles, fire-resistant inorganic particles, binder resin, and water are mixed to prepare a slurry. In the compression molding step, the slurry is placed in a mold and compression molded under heating to produce a molded body. [Explanation of symbols]

[0088] 1: cell accommodating member, 2: housing, 20: internal space, 200: cell chamber, 21: cylindrical wall portion, 210: first wall, 210a: first guide groove, 211: second wall, 211a: second guide groove, 22: bottom wall portion, 220: mounting opening, 23: opening, 3: inter-cell separator, 30: inter-cell separator side slit, 31: cell spacing wall portion, 4: elastic member, 5: interlayer separator, 50: inter-layer separator side slit, 6: cooling member, 60: flow path, 7: cooling circuit, 70: radiator, 71: pump, 8: laminate, 80: cell, 800: terminal, 9: vehicle-mounted battery module, C: coolant, T: thickness

Claims

1. A cell housing member for housing a stack of multiple cells for a secondary battery, comprising: The extending direction of the laminate is the lamination direction, a housing having an internal space in which the laminate is housed; an inter-cell separator that is disposed in the internal space and interposed between any pair of the cells adjacent to each other in the stacking direction, the inter-cell separator having electrical insulation and heat insulation properties; an elastic member that is disposed in the inter-cell separator, elastically contacts the adjacent cell in the stacking direction, and is more likely to elastically deform in response to deformation of the cell than the inter-cell separator; Equipped with the inter-cell separator is separate from the housing, and is assembled to the housing and positioned relative to the housing to partition the internal space into a plurality of cell chambers; The cell is a cell containing member that is contained in the cell chamber.

2. The cell is a rectangular cell, The cell housing member according to claim 1 , which is used in an on-vehicle battery module.

3. The cell containment member according to claim 1 , wherein the elastic member is disposed on an inner side of the inter-cell separator when viewed in the stacking direction.

4. A direction intersecting the stacking direction is defined as a juxtaposition direction, The internal space accommodates a plurality of the stacks arranged in the juxtaposition direction, 2. The cell housing member according to claim 1, further comprising an interlayer separator disposed in the internal space and interposed between any pair of adjacent laminates, the interlayer separator having electrical insulation and heat insulation properties.

5. the inter-cell separator has an inter-cell separator side slit, the interlayer separator has an interlayer separator-side slit, 5. The cell container member according to claim 4, wherein the inter-cell separator side slit and the inter-layer separator side slit are fitted together, so that the inter-cell separator and the inter-layer separator are assembled in a cross shape.

6. A direction intersecting a plane including the stacking direction and the juxtaposition direction is defined as a cell insertion / removal direction, The cell containing member described in claim 4, wherein the housing is a one-piece body and has a cylindrical wall portion extending in the cell insertion / removal direction, a bottom wall portion sealing one end of the cylindrical wall portion in the cell insertion / removal direction, and an opening portion opened at the other end of the cylindrical wall portion in the cell insertion / removal direction.

7. The cylindrical wall portion includes a pair of first walls extending in the stacking direction and arranged at a predetermined interval in the juxtaposition direction, The cell container member according to claim 6 , wherein an inner surface of the first wall has a first guide groove into which at least an outer edge of the inter-cell separator is inserted, out of the inter-cell separator and the elastic member.

8. The cylindrical wall portion has a pair of second walls extending in the juxtaposition direction and arranged at a predetermined interval in the stacking direction, The cell container member according to claim 6 , wherein an inner surface of the second wall has a second guide groove into which an outer edge of the interlayer separator is inserted.

9. The cell housing member according to claim 6 , further comprising a cooling member disposed on the bottom wall portion and configured to cool the cell.

10. A cell housing member for housing a stack of multiple cells for a secondary battery, comprising: The extending direction of the laminate is the lamination direction, a housing having an internal space in which the laminate is housed; an inter-cell separator that is disposed in the internal space and interposed between any pair of the cells adjacent to each other in the stacking direction, the inter-cell separator having electrical insulation and heat insulation properties; an elastic member that is disposed in the inter-cell separator, elastically contacts the adjacent cell in the stacking direction, and is more likely to elastically deform in response to deformation of the cell than the inter-cell separator; Equipped with A direction intersecting the stacking direction is defined as a juxtaposition direction, The internal space accommodates a plurality of the stacks arranged in the juxtaposition direction, The laminate further includes an interlayer separator that is disposed in the internal space, is interposed between any pair of adjacent laminates, and has electrical insulation and heat insulation properties, the inter-cell separator has an inter-cell separator side slit, the interlayer separator has an interlayer separator-side slit, The inter-cell separator side slit and the inter-layer separator side slit are fitted together to assemble the inter-cell separator and the inter-layer separator in a cross shape in the cell housing member.

11. A cell housing member for housing a stack of multiple cells for a secondary battery, comprising: The extending direction of the laminate is the lamination direction, a housing having an internal space in which the laminate is housed; an inter-cell separator that is disposed in the internal space and interposed between any pair of the cells adjacent to each other in the stacking direction, the inter-cell separator having electrical insulation and heat insulation properties; an elastic member that is disposed in the inter-cell separator, elastically contacts the adjacent cell in the stacking direction, and is more likely to elastically deform in response to deformation of the cell than the inter-cell separator; Equipped with A direction intersecting the stacking direction is defined as a juxtaposition direction, The internal space accommodates a plurality of the stacks arranged in the juxtaposition direction, The laminate further includes an interlayer separator that is disposed in the internal space, is interposed between any pair of adjacent laminates, and has electrical insulation and heat insulation properties, A direction intersecting a plane including the stacking direction and the juxtaposition direction is defined as a cell insertion / removal direction, the housing is an integral body and has a cylindrical wall portion extending in the cell insertion / removal direction, a bottom wall portion sealing one end of the cylindrical wall portion in the cell insertion / removal direction, and an opening portion opened at the other end of the cylindrical wall portion in the cell insertion / removal direction, The cylindrical wall portion includes a pair of first walls extending in the stacking direction and arranged at a predetermined interval in the juxtaposition direction, The inner surface of the first wall is a cell containing member having a first guide groove into which at least an outer edge of the inter-cell separator and the elastic member is inserted.

12. A cell housing member for housing a stack of multiple cells for a secondary battery, comprising: The extending direction of the laminate is the lamination direction, a housing having an internal space in which the laminate is housed; an inter-cell separator that is disposed in the internal space and interposed between any pair of the cells adjacent to each other in the stacking direction, the inter-cell separator having electrical insulation and heat insulation properties; an elastic member that is disposed in the inter-cell separator, elastically contacts the adjacent cell in the stacking direction, and is more likely to elastically deform in response to deformation of the cell than the inter-cell separator; Equipped with A direction intersecting the stacking direction is defined as a juxtaposition direction, The internal space accommodates a plurality of the stacks arranged in the juxtaposition direction, The laminate further includes an interlayer separator that is disposed in the internal space, is interposed between any pair of adjacent laminates, and has electrical insulation and heat insulation properties, A direction intersecting a plane including the stacking direction and the juxtaposition direction is defined as a cell insertion / removal direction, the housing is an integral body and has a cylindrical wall portion extending in the cell insertion / removal direction, a bottom wall portion sealing one end of the cylindrical wall portion in the cell insertion / removal direction, and an opening portion opened at the other end of the cylindrical wall portion in the cell insertion / removal direction, The cylindrical wall portion has a pair of second walls extending in the juxtaposition direction and arranged at a predetermined interval in the stacking direction, The inner surface of the second wall of the cell container member has a second guide groove into which an outer edge of the interlayer separator is inserted.

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