Battery module and spacer

Abstract

To provide a battery module and a spacer which appropriately cool battery cells.SOLUTION: In a battery module, a plurality of battery cells 20 and spacers 13 which are arranged between the battery cells 20 and are made of a synthetic resin are alternately stacked. The spacer 13 has a plurality of bar parts 50 arrayed at intervals along the battery cells 20, fin parts 56 and 59 which are provided on the bar part 50, are inclined in an array direction in which the bar parts 50 are arrayed and are formed so as to extend to a side of a first battery cell 20A, and are brought into contact with a surface of the first battery cell 20A, and fin parts 57 and 58 which are provided on the bar parts 50, are inclined in the array direction and are formed so as to extend to a side of a second battery cell 20B, and are brought into contact with a surface of the second battery cell 20B. An interval P1 between a first bar part 51 and a second bar part 52 close to a center in the array direction is wider than an interval P2 between the first bar part 51 and a third bar part 53 other than the one close to the center and an interval P3 between the second bar part 52 and a fourth bar part 54.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a battery module and a spacer.

Background Art

[0002] In the battery module described in Patent Document 1, a spacer is disposed between battery cells. In the spacer, a notch portion penetrating the wall portion in the thickness direction is formed in a wall portion sandwiched between main surfaces of two adjacent battery cells. Then, by using such a spacer and passing a cooling gas through the notch portion, an increase in the temperature difference between adjacent battery cells via the spacer is reduced.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the technology as described in the above Patent Document 1, there is a possibility that the passage path of the cooling gas penetrating the spacer in the thickness direction becomes narrower than expected. That is, in the battery module, the internal pressure of the battery cells may increase due to the gas generated inside the case and the cells may expand. A part of the expanded battery cells may enter the passage path of the cooling gas provided in the spacer. That is, when expansion occurs in the battery cells, the passage path of the cooling gas provided in the spacer may become narrower than when no expansion occurs in the battery cells. As a result, the cooling of the battery cells may not be appropriately performed.

Means for Solving the Problems

[0005] A battery module that solves the above problems is a battery module in which a plurality of battery cells and synthetic resin spacers arranged between the battery cells are alternately stacked, wherein the spacers have a plurality of bar portions arranged at intervals from each other along the battery cells, a first fin portion provided on the bar portions and formed to extend toward one of the battery cells at an angle with respect to the arrangement direction of the bar portions and in contact with the surface of the one battery cell, and a second fin portion provided on the bar portions and formed to extend toward the other battery cell that is different from the one battery cell at an angle with respect to the arrangement direction and in contact with the surface of the other battery cell, wherein the spacing between the plurality of bar portions closer to the center in the arrangement direction is wider than the spacing between the plurality of bar portions other than those closer to the center.

[0006] With the above configuration, the first fin portion contacts the surface of one battery cell, thereby ensuring an appropriate distance from the surface of one battery cell, and the second fin portion contacts the surface of the other battery cell, thereby ensuring an appropriate distance from the surface of the other battery cell. As a result, the spacer can ensure an appropriate distance between adjacent battery cells. Therefore, heat can be properly dissipated into the space between the battery cells, and the battery cells can be properly cooled. In addition, the spacing between the multiple bar portions near the center in the arrangement direction is wider than the spacing between the multiple bar portions other than those near the center. As a result, when the battery cells are pressed by the bar portions of the spacer placed between them, the pressure on the battery cells near the center by the bar portions is lower than on the battery cells other than those near the center. This makes it possible to suppress the pressure on the center when the battery cells expand due to charging and discharging.

[0007] With respect to the above-mentioned battery module, the length of each of the first fin portion and the second fin portion is corresponding to the spacing of the bar portions, and it is preferable that the lengths of the first fin portion and the second fin portion located closer to the center in the arrangement direction are longer than the lengths of the first fin portion and the second fin portion located other than closer to the center in the arrangement direction.

[0008] According to the above configuration, by widening the spacing between the bar sections near the center in the arrangement direction, pressure on the central part of the battery cell can be suppressed, while the first and second fin sections contact the battery cell, thereby suppressing excessive deformation of the battery cell.

[0009] A battery module that solves the above problems is a battery module in which a plurality of battery cells and synthetic resin spacers arranged between the battery cells are alternately stacked, wherein the spacers have a plurality of bar portions arranged at intervals from each other along the battery cells, a first fin portion provided on the bar portions and formed to extend toward one of the battery cells at an angle with respect to the arrangement direction of the bar portions and in contact with the surface of the one battery cell, and a second fin portion provided on the bar portions and formed to extend toward the other battery cell different from the one battery cell at an angle with respect to the arrangement direction and in contact with the surface of the other battery cell, wherein the spacing between the plurality of bar portions near the bottom surface in the arrangement direction is wider than the spacing between the plurality of bar portions other than those near the bottom surface.

[0010] With the above configuration, the first fin portion contacts the surface of one battery cell, thereby ensuring an appropriate distance from the surface of one battery cell, and the second fin portion contacts the surface of the other battery cell, thereby ensuring an appropriate distance from the surface of the other battery cell. As a result, the spacer can ensure an appropriate distance between adjacent battery cells. Therefore, heat can be properly dissipated into the space between the battery cells, and the battery cells can be properly cooled. In addition, the spacing between the multiple bar portions near the bottom surface in the arrangement direction is wider than the spacing between the multiple bar portions other than those near the bottom surface. As a result, when the battery cells are pressed by the bar portions of the spacer placed between them, the pressure on the bottom surface of the battery cells by the bar portions is lower than on other parts of the battery cells. This makes it possible to suppress the pressure on the bottom surface when the battery cells expand due to charging and discharging.

[0011] With respect to the above-mentioned battery module, the length of each of the first fin portion and the second fin portion is corresponding to the spacing of the bar portions, and it is preferable that the lengths of the first fin portion and the second fin portion located closer to the bottom surface in the arrangement direction are longer than the lengths of the first fin portion and the second fin portion located at locations other than closer to the bottom surface in the arrangement direction.

[0012] According to the above configuration, by widening the spacing between the bar portions closer to the arrangement direction, pressure on the bottom surface of the battery cell can be suppressed, while the first and second fin portions contact the battery cell, thereby suppressing excessive deformation of the battery cell.

[0013] With respect to the above-mentioned battery module, it is preferable that the first fin portion and the second fin portion are provided on the same bar portion among the plurality of bar portions. According to the above configuration, a first fin section and a second fin section are provided on the same bar section. Therefore, insulation can be ensured by the first fin section and the second fin section making contact with both adjacent battery cells.

[0014] With respect to the above-mentioned battery module, it is preferable that the first fin portion is inclined with respect to the first arrangement direction, and the second fin portion is inclined with respect to the second arrangement direction opposite to the first arrangement direction.

[0015] According to the above configuration, the first fin portion is inclined with respect to the first arrangement direction, and the second fin portion is inclined with respect to the second arrangement direction. Therefore, insulation can be ensured by the first fin portion and the second fin portion contacting both adjacent battery cells at different positions.

[0016] With respect to the above-described battery module, it is preferable that the first fin portion is provided on the first bar portion among the plurality of bar portions, and the second fin portion is provided on the second bar portion, which is different from the first bar portion among the plurality of bar portions.

[0017] According to the above configuration, the first fin portion is provided on the first bar portion, and the second fin portion is provided on a second bar portion different from the first bar portion. Therefore, insulation can be ensured by the first bar portion on which the first fin is provided and the second bar portion on which the second fin is provided separately contacting both adjacent battery cells.

[0018] Preferably, the above-described battery module includes two first fin portions, one of which is inclined with respect to a first arrangement direction and the other of which is inclined with respect to a second arrangement direction opposite to the first arrangement direction, and also includes two second fin portions, one of which is inclined with respect to a first arrangement direction and the other of which is inclined with respect to a second arrangement direction.

[0019] According to the above configuration, the first bar portion is provided with a first fin portion inclined with respect to the first arrangement direction and a second fin portion inclined with respect to the second arrangement direction, and the second bar portion is provided with a first fin portion inclined with respect to the first arrangement direction and a second fin portion inclined with respect to the second arrangement direction. As a result, at least two fin portions from each bar portion are in contact with the battery cells. Thus, insulation between two adjacent battery cells can be ensured.

[0020] Preferably, the battery module includes the first fin portion inclined with respect to the first array direction, the second fin portion inclined with respect to the first array direction, a first stopper portion formed on the first bar portion extending in the second array direction opposite to the first array direction, and a second stopper portion formed on the second bar portion extending in the second array direction.

[0021] According to the above configuration, the first bar portion is provided with a first fin portion inclined with respect to the first arrangement direction and a first stopper portion extending in the second arrangement direction, and the second bar portion is provided with a first fin portion inclined with respect to the first arrangement direction and a second stopper portion extending in the second arrangement direction. As a result, at least the fin portion and the stopper portion from each bar portion are in contact with the battery cell. Thus, insulation between two adjacent battery cells can be ensured.

[0022] The spacer for solving the above problems is a synthetic resin spacer disposed between a plurality of battery cells constituting a battery module, which includes a plurality of bar portions arranged at intervals from each other, and a first fin portion provided on a first bar portion included in the bar portions, extending in a first orthogonal direction that is inclined with respect to a first arrangement direction in the arrangement direction in which the bar portions are arranged and orthogonal to the arrangement direction, and a second fin portion provided on the first bar portion, extending in the first orthogonal direction while being inclined with respect to a second arrangement direction opposite to the first arrangement direction, and the interval between the plurality of bar portions closer to the center in the arrangement direction is wider than the interval between the plurality of bar portions other than those closer to the center.

[0023] According to the above configuration, when the first fin portion contacts the surface of one battery cell, the distance from the surface of one battery cell can be appropriately ensured, and when the second fin portion contacts the surface of the other battery cell, the distance from the surface of the other battery cell can be appropriately ensured. Therefore, the spacer can appropriately ensure the distance between adjacent battery cells. Thus, heat dissipation to the space between the battery cells can be appropriately performed, and the battery cells can be appropriately cooled. Also, the interval between the plurality of bar portions closer to the center in the arrangement direction is wider than the interval between the plurality of bar portions other than those closer to the center. For this reason, when the battery cells are pressed by the bar portions of the spacer disposed between the battery cells, the pressing of the battery cells closer to the center by the bar portions becomes lower than that of the battery cells other than those closer to the center. Thereby, when the battery cells expand during charge and discharge, the pressing against the center can be suppressed.

[0024] Regarding the above spacer, each of the first fin portion and the second fin portion has a length corresponding to the interval of the bar portions, and it is preferable that the lengths of the first fin portion and the second fin portion located closer to the center in the arrangement direction are longer than the lengths of the first fin portion and the second fin portion located other than closer to the center in the arrangement direction.

[0025] According to the above configuration, by widening the distance between the bar portions closer to the center in the array direction, the pressing closer to the center of the battery cell is suppressed, and the first fin portion and the second fin portion contact the battery cell, so that excessive deformation of the battery cell can be suppressed.

[0026] The spacer for solving the above problems is a synthetic resin spacer disposed between a plurality of battery cells constituting a battery module, including a plurality of bar portions arranged at intervals from each other, and provided on a first bar portion included in the bar portion, and inclined with respect to a first array direction in the array direction in which the bar portions are arranged and extending in a first orthogonal direction orthogonal to the array direction. A first fin portion formed, and a second fin portion provided on the first bar portion and inclined with respect to a second array direction opposite to the first array direction and extending in the first orthogonal direction, and the plurality of bar portions closer to the bottom surface in the array direction The interval is wider than the interval between the plurality of bar portions other than those closer to the bottom surface.

[0027] According to the above configuration, the first fin portion can appropriately secure the distance from the surface of one battery cell by contacting the surface of one battery cell, and the second fin portion can appropriately secure the distance from the surface of the other battery cell by contacting the surface of the other battery cell. Therefore, the distance between adjacent battery cells can be appropriately secured by the spacer. Therefore, heat dissipation to the space between the battery cells is appropriately performed, and the battery cells can be appropriately cooled. In addition, the interval between the plurality of bar portions closer to the bottom surface in the array direction is wider than the interval between the plurality of bar portions other than those closer to the bottom surface. Therefore, when the battery cells are pressed by the bar portions of the spacer disposed between the battery cells, the pressing of the battery cells closer to the bottom surface by the bar portions becomes lower than that other than the bottom surface of the battery cells. Thereby, when the battery cells expand with charging and discharging, the pressing against the bottom surface can be suppressed.

[0028] With respect to the above-mentioned spacer, the length of each of the first fin portion and the second fin portion is corresponding to the distance between the bar portions, and it is preferable that the lengths of the first fin portion and the second fin portion located closer to the bottom surface in the arrangement direction are longer than the lengths of the first fin portion and the second fin portion located at locations other than closer to the bottom surface in the arrangement direction.

[0029] According to the above configuration, by widening the spacing between the bar portions near the bottom surface in the arrangement direction, the pressure on the bottom surface of the battery cell can be suppressed, while the first fin portion and the second fin portion contact the battery cell, thereby suppressing excessive deformation of the battery cell. [Effects of the Invention]

[0030] According to the present invention, battery cells can be properly cooled. [Brief explanation of the drawing]

[0031] [Figure 1] This is a perspective view showing the schematic configuration of a battery module according to the first embodiment. [Figure 2] This is a cross-sectional view of the battery module of the same embodiment, shown in line 2-2 of Figure 1. [Figure 3] This is a perspective view of the spacer of the same embodiment. [Figure 4] This is a cross-sectional view of the space-forming portion of the spacer in the uncompressed state of the same embodiment. [Figure 5] This is a cross-sectional view of the space-forming portion of the spacer in the compressed state of the same embodiment. [Figure 6] This is a cross-sectional view of the space-forming portion of the spacer in the uncompressed state of the second embodiment. [Figure 7] This is a cross-sectional view of the space-forming portion of the spacer in the compressed state of the same embodiment. [Figure 8] This is a cross-sectional view of the space-forming portion of the spacer in the uncompressed state of the third embodiment. [Figure 9] This is a cross-sectional view of the space-forming portion of the spacer in the compressed state of the same embodiment. [Figure 10]This is a cross-sectional view of the space-forming portion of the spacer in the uncompressed state of the fourth embodiment. [Figure 11] This is a cross-sectional view of the space-forming portion of the spacer in the compressed state of the same embodiment. [Modes for carrying out the invention]

[0032] (First Embodiment) The first embodiment of the battery module and spacer will be described below with reference to Figures 1 to 5.

[0033] (Battery module 10) As shown in Figure 1, the battery module 10 houses multiple battery cells 20 in a lower case 11. The lower case 11 is a box-shaped member with an open top. The outer shape of the battery cell 20 is a flattened rectangular parallelepiped. Multiple battery cells 20 are stacked inside the lower case 11. The battery cell 20 has a surface in the X direction, which is the stacking direction of the battery cell 20. Surface 21 of the battery cell 20 is the surface with the largest area among the outer surfaces. The battery module 10 houses two rows of stacked battery cells 20. The direction in which the rows of battery cell groups 20 are aligned is the Y direction. The direction of the top surface of the lower case 11 is the Z direction. In reality, the battery module 10 has busbars, pole terminals, an upper case, etc. attached to it, but these are omitted in the diagram.

[0034] As shown in Figure 2, the lower case 11 has a floor section 11A and an end wall section 11B. The floor section 11A is the part of the lower case 11 located below the multiple battery cells 20. The end wall section 11B is the part of the lower case 11 located to the side of the multiple battery cells 20. The multiple battery cells 20 housed in the lower case 11 are stacked alternately with spacers 13. In other words, spacers 13 are placed between the battery cells 20. End plates 14 are sandwiched between the battery cells 20 at both ends and the end wall section 11B. The spacers 13 and end plates 14 are made of synthetic resin. The spacers 13 and end plates 14 have insulating properties and a certain degree of elasticity.

[0035] The battery cell 20, spacer 13, and end plate 14 are constrained by the end wall portions 11B at both ends in the stacking direction (X direction). Therefore, the battery cell 20, spacer 13, and end plate 14 are subjected to a compressive load in the stacking direction (X direction). The compressed battery cell 20, spacer 13, and end plate 14 housed in the battery module 10 are more compressed in the stacking direction (X direction) than when they are in an uncompressed state.

[0036] (Spacer 13) As shown in Figure 3, the spacer 13 has a space-forming portion 13C. The space-forming portion 13C is located in the central part of the spacer 13. The space-forming portion 13C is the part that forms a space between the battery cells 20 located on either side of the spacer 13.

[0037] The spacer 13 has a space-forming section 13C that includes a plurality of bar sections 50. The bar sections 50 extend in the longitudinal direction (Y direction) of the surface 21 of the battery cell 20. The plurality of bar sections 50 are arranged along the surface 21 of the battery cell 20 with spacing between them in the vertical direction (Z direction). Fin sections 55 are provided on the plurality of bar sections 50. The space-forming section 13C is composed of the bar sections 50 and the fin sections 55.

[0038] (Space forming part 13C) Next, the space-forming portion 13C will be described in detail with reference to Figures 4 and 5. Figures 4 and 5 are cross-sectional views of the space-forming portion 13C of the spacer 13. Figure 4 shows the space-forming portion 13C in an uncompressed state together with the adjacent battery cells 20. Figure 5 shows the space-forming portion 13C in a compressed state together with the adjacent battery cells 20.

[0039] As shown in Figure 4, the bar section 50 has, from top to bottom, a third bar section 53, a first bar section 51, a second bar section 52, and a fourth bar section 54. The spacing of the bar sections 50 closer to the center in the arrangement direction is wider than the spacing of the bar sections 50 further away from the center. That is, the spacing P1 between the first bar section 51 and the second bar section 52 is longer than the spacing P2 between the first bar section 51 and the third bar section 53 and the spacing P3 between the second bar section 52 and the fourth bar section 54 (P1>P2, P1>P3). The constraint range PX of the electrode body within the battery cell 20 is the range from the upper surface of the third bar section 53 to the lower surface of the fourth bar section 54. The spacing P1 is preferably 35-60% of the constraint range PX of the electrode body in the arrangement direction of the surface 21 of the battery cell 20. The fin section 55 has a first fin section 56, a second fin section 57, a third fin section 58, and a fourth fin section 59.

[0040] The first bar portion 51 is provided with a first fin portion 56 and a second fin portion 57. The first fin portion 56 is formed extending in a first orthogonal direction (right in the figure) perpendicular to the arrangement direction (Z direction), at a first angle θA inclined with respect to the first arrangement direction (upward direction) in the arrangement direction (Z direction) in which the bar portions 50 are arranged. The second fin portion 57 is formed extending in a second orthogonal direction (left in the figure) opposite to the first orthogonal direction, at a second angle θB inclined with respect to the second arrangement direction (downward direction) opposite to the first arrangement direction. The first fin portion 56 is in contact with the surface 21 of the first battery cell 20A on the right side in the figure. The second fin portion 57 is in contact with the surface 21 of the second battery cell 20B on the left side in the figure. The first angle θA and the second angle θB are different angles. The first angle θA is a larger angle than the second angle θB.

[0041] The second bar portion 52 is provided with a third fin portion 58 and a fourth fin portion 59. The third fin portion 58 is formed extending in a second orthogonal direction (left direction in the figure) perpendicular to the array direction (Z direction) at a third angle θC with respect to the second array direction (downward direction). The second fin portion 57 is formed extending in a first orthogonal direction (right direction in the figure) at a fourth angle θD with respect to the first array direction (upward direction). The third fin portion 58 is in contact with the surface 21 of the second battery cell 20B on the left side of the figure. The fourth fin portion 59 is in contact with the surface 21 of the first battery cell 20A on the right side of the figure. The third angle θC and the fourth angle θD are different angles. The third angle θC is a larger angle than the fourth angle θD.

[0042] A third fin portion 58 is provided on the third bar portion 53. The third fin portion 58 is formed extending in the second orthogonal direction (left direction in the figure) at a third angle θC with respect to the second alignment direction (downward direction). The third fin portion 58 is in contact with the surface 21 of the second battery cell 20B on the left side.

[0043] The fourth bar portion 54 is provided with a first fin portion 56. The first fin portion 56 is formed extending in a first orthogonal direction (to the right in the figure) at a first angle θA inclined with respect to the first arrangement direction (upward direction). The first fin portion 56 is in contact with the surface 21 of the right-side first battery cell 20A.

[0044] (Uncompressed state) As shown in FIG. 4, in the non-compressed state, the tip of the first fin portion 56 provided on the first bar portion 51 protrudes toward the first battery cell 20A side on the right side in the drawing rather than the first bar portion 51. In the non-compressed state, the tip of the second fin portion 57 provided on the first bar portion 51 protrudes toward the second battery cell 20B side on the left side in the drawing rather than the first bar portion 51. In the non-compressed state, the tip of the third fin portion 58 provided on the second bar portion 52 protrudes toward the second battery cell 20B side on the left side rather than the second bar portion 52. In the non-compressed state, the tip of the fourth fin portion 59 provided on the second bar portion 52 protrudes toward the first battery cell 20A side on the right side rather than the second bar portion 52. The tip of the third fin portion 58 provided on the third bar portion 53 protrudes toward the second battery cell 20B side on the left side rather than the third bar portion 53. The tip of the first fin portion 56 provided on the fourth bar portion 54 protrudes toward the first battery cell 20A side on the right side rather than the fourth bar portion 54. The first bar portion 51, the second bar portion 52, the third bar portion 53, and the fourth bar portion 54 do not contact either the surface 21 of the first battery cell 20A on the right side or the surface 21 of the second battery cell 20B on the left side.

[0045] The first fin length LA, which is the length of the first fin portion 56 from the first bar portion 51, and the third fin length LC, which is the length of the third fin portion 58 from the third bar portion 53, are both shorter than the distance P2 between the first bar portion 51 and the third bar portion 53 (LA < P2, LC < P2). The first fin length LA and the third fin length LC are the same length (LA = LC). The sum of the first fin length LA and the third fin length LC is longer than the distance P2 between the first bar portion 51 and the third bar portion 53 (LA + LC > P2).

[0046] The second fin length LB, which is the length of the second fin portion 57 from the first bar portion 51, and the fourth fin length LD, which is the length of the fourth fin portion 59 from the second bar portion 52, are both shorter than the interval P1 between the first bar portion 51 and the second bar portion 52 (LB < P1, LD < P1). The second fin length LB and the fourth fin length LD are of the same length (LB = LD). The sum of the second fin length LB and the fourth fin length LD is longer than the interval P1 between the first bar portion 51 and the second bar portion 52 (LB + LD > P1). The second fin length LB, which is the length of the second fin portion 57 from the first bar portion 51, is longer than the first fin length LA, which is the length of the first fin portion 56 from the first bar portion 51 (LB > LA).

[0047] The third fin length LC, which is the length of the third fin portion 58 from the second bar portion 52, and the first fin length LA, which is the length of the first fin portion 56 from the fourth bar portion 54, are both shorter than the interval P3 between the second bar portion 52 and the fourth bar portion 54 (LC < P3, LA < P3). The third fin length LC and the first fin length LA are of the same length (LC = LA). The sum of the third fin length LC and the first fin length LA is longer than the interval P3 between the second bar portion 52 and the fourth bar portion 54 (LC + LA > P3). The fourth fin length LD, which is the length of the fourth fin portion 59 from the second bar portion 52, is longer than the third fin length LC, which is the length of the third fin portion 58 from the second bar portion 52 (LD > LC).

[0048] The sum of the projection lengths LZA and LZC in the arrangement direction (Z direction) of the first fin portion 56 and the third fin portion 58 is shorter than the interval P2 between the first bar portion 51 and the third bar portion 53 in the non-compressed state (LZA + LZC < P2). For this reason, in the non-compressed state, a gap G2 is provided in the arrangement direction (Z direction) between the tips of the first fin portion 56 and the third fin portion 58. As a result, the first fin portion 56 and the third fin portion 58 do not overlap in the arrangement direction (Z direction). Such a spacer 13 can be manufactured at a low cost.

[0049] The sum of the projected length LZB in the array direction (Z direction) of the second fin portion 57 and the projected length LZD in the array direction (Z direction) of the fourth fin portion 59 is shorter than the distance P1 between the first bar portion 51 and the second bar portion 52 in the non-compressed state (LZB + LZD < P1). Therefore, in the non-compressed state, a gap G1 is provided in the array direction (Z direction) between the tips of the second fin portion 57 and the fourth fin portion 59. As a result, the second fin portion 57 and the fourth fin portion 59 do not overlap in the array direction (Z direction). Such a spacer 13 can be manufactured at a low cost.

[0050] The sum of the projected length LZC in the array direction (Z direction) of the third fin portion 58 and the projected length LZA in the array direction (Z direction) of the first fin portion 56 is shorter than the distance P3 between the second bar portion 52 and the fourth bar portion 54 in the non-compressed state (LZC + LZA < P3). Therefore, in the non-compressed state, a gap G3 is provided in the array direction (Z direction) between the tips of the third fin portion 58 and the first fin portion 56. As a result, the third fin portion 58 and the first fin portion 56 do not overlap in the array direction (Z direction). Such a spacer 13 can be manufactured at a low cost.

[0051] (Compressed state) As shown in FIG. 5, in the compressed state, the right side surface of the bar portion 50 is in contact with the surface 21 of the right first battery cell 20A. The surface 21 of the left second battery cell 20B is in contact with the left side surface of the bar portion 50. That is, in the compressed state, the bar portion 50 is sandwiched between the surface 21 of the first battery cell 20A and the surface 21 of the second battery cell 20B, and is compressed in the stacking direction (X direction). Further, the bar portion 50 presses the surface 21 of the first battery cell 20A and the surface 21 of the second battery cell 20B in a direction away from each other by the reaction force against the compression. As a result, the contact between the adjacent battery cells 20 on both sides is suppressed by the bar portion 50. And a space 15 is formed between the two adjacent bar portions 50 in the vertical direction, in which the surfaces 21 of the battery cells 20 adjacent to both sides of the spacer 13 are separated from each other.

[0052] The right side of the first bar portion 51 is in contact with the surface 21 of the right first battery cell 20A, causing the first fin portion 56 provided on the first bar portion 51 to be pressed to the left by the surface 21 of the right first battery cell 20A. Due to this pressure, the first fin portion 56 is bent to the left along the surface 21 of the right first battery cell 20A compared to when it is uncompressed. In this bent state, the first fin portion 56 extends upward along the surface 21 of the right first battery cell 20A. The reaction force of this bending then presses the surface 21 of the right first battery cell 20A to the right.

[0053] The left side surface of the first bar portion 51 is in contact with the left side surface 21 of the second battery cell 20B, causing the second fin portion 57 provided on the first bar portion 51 to be pressed to the right by the left side surface 21 of the second battery cell 20B. Due to this pressure, the second fin portion 57 is bent to the right along the left side surface 21 of the second battery cell 20B compared to when it is uncompressed. In this bent state, the second fin portion 57 extends downward along the left side surface 21 of the second battery cell 20B. The reaction force of this bending then presses the left side surface 21 of the second battery cell 20B to the left.

[0054] As the right side of the second bar portion 52 is in contact with the surface 21 of the right first battery cell 20A, the fourth fin portion 59 provided on the second bar portion 52 is pressed to the left by the surface 21 of the right first battery cell 20A. Due to this pressure, the fourth fin portion 59 is bent to the left along the surface 21 of the right first battery cell 20A compared to when it is uncompressed. In this bent state, the fourth fin portion 59 extends upward along the surface 21 of the right first battery cell 20A. Then, due to the reaction force of its bending, the bent fourth fin portion 59 presses the surface 21 of the right first battery cell 20A to the right.

[0055] As the left side surface of the second bar portion 52 is in contact with the left side surface 21 of the second battery cell 20B, the third fin portion 58 provided on the second bar portion 52 is pressed to the right by the left side surface 21 of the second battery cell 20B. Due to this pressure, the third fin portion 58 is bent to the right along the left side surface 21 of the second battery cell 20B compared to when it is uncompressed. In this bent state, the second fin portion 58 extends downward along the left side surface 21 of the second battery cell 20B. Furthermore, the bent third fin portion 58, due to the reaction force of its bending, presses the left side surface 21 of the second battery cell 20B to the left.

[0056] The left side of the third bar portion 53 is in contact with the left side surface 21 of the left second battery cell 20B, causing the third fin portion 58 provided on the third bar portion 53 to be pressed to the right by the left side surface 21 of the second battery cell 20B. Due to this pressure, the third fin portion 58 is bent to the right along the left side surface 21 of the second battery cell 20B compared to when it is uncompressed. In this bent state, the third fin portion 58 extends downward along the left side surface 21 of the second battery cell 20B. The reaction force of this bending then presses the left side surface 21 of the second battery cell 20B to the left.

[0057] The right side of the fourth bar portion 54 is in contact with the surface 21 of the right first battery cell 20A, causing the first fin portion 56 provided on the fourth bar portion 54 to be pressed to the left by the surface 21 of the right first battery cell 20A. Due to this pressure, the first fin portion 56 is bent to the left along the surface 21 of the right first battery cell 20A compared to when it is uncompressed. In this bent state, the first fin portion 56 extends upward along the surface 21 of the right first battery cell 20A. The reaction force of this bending then presses the surface 21 of the right first battery cell 20A to the right.

[0058] As mentioned above, the first fin length LA of the first fin portion 56 and the third fin length LC of the third fin portion 58 are both shorter than the distance P2 between the first bar portion 51 and the third bar portion 53. Therefore, on the right side of the first battery cell 20A, there is a portion of the surface 21 that is not covered by the first fin portion 56 in the distance P2 between the first bar portion 51 and the third bar portion 53. Similarly, on the left side of the second battery cell 20B, there is a portion of the surface 21 that is not covered by the third fin portion 58 in the distance P2 between the first bar portion 51 and the third bar portion 53.

[0059] Similarly, the second fin length LB of the second fin section 57 and the fourth fin length LD of the fourth fin section 59 are both shorter than the distance P1 between the first bar section 51 and the second bar section 52. As a result, on the right side of the first battery cell 20A, there is a portion of the distance P1 between the first bar section 51 and the second bar section 52 that is not covered by the fourth fin section 59. Also, on the left side of the second battery cell 20B, there is a portion of the distance P1 between the first bar section 51 and the second bar section 52 that is not covered by the second fin section 57.

[0060] Similarly, the third fin length LC of the third fin portion 58 and the first fin length LA of the first fin portion 56 are both shorter than the distance P3 between the second bar portion 52 and the fourth bar portion 54. As a result, on the left side of the second battery cell 20B, there is a portion of the distance P3 between the second bar portion 52 and the fourth bar portion 54 that is not covered by the third fin portion 58. Also, on the right side of the first battery cell 20A, there is a portion of the distance P3 between the second bar portion 52 and the fourth bar portion 54 that is not covered by the first fin portion 56.

[0061] Therefore, the surfaces 21 of the battery cells 20 adjacent to the spacer 13 have portions exposed to the space 15 in the gap between the bar portions 50. In other words, when the battery cells 20 adjacent to the spacer 13 generate heat, they can dissipate heat into the space 15. The space 15 is the passage path for the cooling gas used to cool the battery cells 20 in the battery module 10. As a result, the spacer 13 can cool the battery cells 20 adjacent to it while suppressing a large temperature difference between the two adjacent battery cells 20.

[0062] Furthermore, as mentioned above, the sum of the first fin length LA of the first fin portion 56 and the third fin length LC of the third fin portion 58 is longer than the distance P2 between the first bar portion 51 and the third bar portion 53. Therefore, in the compressed state, the first fin portion 56 and the third fin portion 58 overlap in the alignment direction (Z direction). In other words, there is an overlap L2 between the tip of the first fin portion 56 and the tip of the third fin portion 58. Thus, the first fin portion 56 presses at least the area of ​​the right-side first battery cell 20A that is opposite to the area of ​​the left-side second battery cell 20B that is not being pressed by the third fin portion 58. The third fin portion 58 presses at least the area of ​​the left-side second battery cell 20B that is opposite to the area of ​​the right-side first battery cell 20A that is not being pressed by the first fin portion 56. In other words, the battery cells 20 adjacent to the spacer 13 have no gap in the arrangement direction (Z direction) at the distance P2 between the first bar portion 51 and the third bar portion 53, and are pressed away from each other by at least one of the first fin portion 56 and the third fin portion 58. Furthermore, the battery cells 20 adjacent to the spacer 13 do not come into contact with each other between the first bar portion 51 and the third bar portion 53. For example, even if the adjacent battery cells 20 expand and enter the space 15 while bending the first fin portion 56 and the third fin portion 58 respectively, at least one of the first fin portion 56 and the third fin portion 58 will always be present between the adjacent battery cells 20. As a result, the spacer 13 can reliably maintain insulation between the adjacent battery cells 20.

[0063] Similarly, the sum of the second fin length LB of the second fin section 57 and the fourth fin length LD of the fourth fin section 59 is longer than the distance P1 between the first bar section 51 and the second bar section 52. Therefore, in the compressed state, the second fin section 57 and the fourth fin section 59 overlap in the alignment direction (Z direction). In other words, there is an overlap L1 between the tip of the second fin section 57 and the tip of the fourth fin section 59. Thus, the second fin section 57 presses at least the area of ​​the left-side second battery cell 20B that is opposite to the area of ​​the right-side first battery cell 20A that is not being pressed by the fourth fin section 59. The fourth fin section 59 presses at least the area of ​​the right-side first battery cell 20A that is opposite to the area of ​​the right-side first battery cell 20A that is not being pressed by the second fin section 57. In other words, the battery cells 20 adjacent to the spacer 13 have no gap in the arrangement direction (Z direction) at the distance P1 between the first bar portion 51 and the second bar portion 52, and are pressed away from each other by at least one of the second fin portion 57 and the fourth fin portion 59. Furthermore, the battery cells 20 adjacent to the spacer 13 do not come into contact with each other between the first bar portion 51 and the second bar portion 52. For example, even if the adjacent battery cells 20 expand and enter the space 15 while bending the second fin portion 57 and the first fin portion 56 respectively, at least one of the second fin portion 57 and the first fin portion 56 will always be present between the adjacent battery cells 20. As a result, the spacer 13 can reliably maintain insulation between the adjacent battery cells 20.

[0064] Similarly, the sum of the third fin length LC of the third fin portion 58 and the first fin length LA of the first fin portion 56 is longer than the distance P3 between the second bar portion 52 and the fourth bar portion 54. Therefore, in the compressed state, the third fin portion 58 and the first fin portion 56 overlap in the alignment direction (Z direction). In other words, there is an overlap L3 between the tip of the third fin portion 58 and the tip of the first fin portion 56. Thus, the first fin portion 56 presses at least the area of ​​the right-side first battery cell 20A that is opposite to the area of ​​the left-side second battery cell 20B that is not being pressed by the third fin portion 58. The third fin portion 58 presses at least the area of ​​the left-side second battery cell 20B that is opposite to the area of ​​the right-side first battery cell 20A that is not being pressed by the first fin portion 56. In other words, the battery cells 20 adjacent to the spacer 13 have no gap in the arrangement direction (Z direction) at the distance P3 between the second bar portion 52 and the fourth bar portion 54, and are pressed away from each other by at least one of the first fin portion 56 and the third fin portion 58. Furthermore, the battery cells 20 adjacent to the spacer 13 do not come into contact with each other between the second bar portion 52 and the fourth bar portion 54. For example, even if the adjacent battery cells 20 expand and enter the space 15 while bending the third fin portion 58 and the first fin portion 56 respectively, at least one of the third fin portion 58 and the first fin portion 56 will always be present between the adjacent battery cells 20. As a result, the spacer 13 can reliably maintain insulation between the adjacent battery cells 20.

[0065] As shown in Figure 5, when the spacer 13 is sandwiched between the surfaces 21 of the adjacent battery cells 20, the battery cell 20 is pressed by the bar portion 50. The distance P1 between the first bar portion 51 and the second bar portion 52 near the center in the arrangement direction is wider than the distance P2 between the first bar portion 51 and the third bar portion 53 and the distance P3 between the second bar portion 52 and the fourth bar portion 54, which are not near the center. Therefore, when the battery cell 20 is pressed by the bar portion 50, the pressure on the battery cell 20 near the center by the bar portion 50 is lower than the pressure on the battery cell 20 outside the center. This makes it possible to suppress the pressure on the center when the battery cell 20 expands due to charging and discharging. For example, if the battery cell 20 is a lithium-ion battery, it is possible to suppress high-rate degradation that occurs when the battery cell 20 is excessively pressed and repeatedly expands and contracts.

[0066] Even if the battery cell 20 expands due to some factor, the spacer 13 can prevent the battery cell 20 from entering the space 15 by pressing the battery cell 20 with the first fin portion 56 and the second fin portion 57. In other words, even if the battery cell 20 expands, the spacer 13 can prevent the length of the space 15 in the stacking direction (X direction) from narrowing, thereby ensuring that the space 15 is properly maintained. As a result, the spacer 13 can prevent the flow rate of the cooling gas flowing through the space 15 from decreasing due to the expansion of the battery cell 20. Thus, the spacer 13 can prevent a decrease in the cooling function of the battery cell 20 by the cooling gas flowing through the space 15.

[0067] Next, the effects of the first embodiment will be described. (1-1) The first fin portion 56 and the fourth fin portion 59 contact the surface 21 of the first battery cell 20A, thereby ensuring an appropriate distance from the surface 21 of the first battery cell 20A, and the second fin portion 57 and the third fin portion 58 contact the surface 21 of the second battery cell 20B, thereby ensuring an appropriate distance from the surface 21 of the second battery cell 20B. As a result, the spacer 13 can ensure an appropriate distance between adjacent battery cells 20. Thus, heat is properly dissipated into the space between the battery cells 20, and the battery cells 20 can be properly cooled. In addition, the distance P1 between the first bar portion 51 and the second bar portion 52 near the center in the arrangement direction is wider than the distance P2 between the first bar portion 51 and the third bar portion 53 and the distance P3 between the second bar portion 52 and the fourth bar portion 54, which are not near the center. Therefore, when the battery cells 20 are pressed by the bar portion 50 of the spacer 13 placed between them, the pressure on the central part of the battery cell 20 by the bar portion 50 is lower than the pressure on other parts of the battery cell 20. This makes it possible to suppress the pressure on the central part when the battery cell 20 expands during charging and discharging.

[0068] (1-2) By widening the spacing of the bar portions 50 closer to the center in the arrangement direction, the pressure on the central part of the battery cell 20 is suppressed, while the second fin portion 57 and the fourth fin portion 59 come into contact with the battery cell 20, thereby suppressing excessive deformation of the battery cell 20.

[0069] (1-3) The same bar portion 50 is provided with a first fin portion 56 and a second fin portion 57. Therefore, insulation can be ensured by the first fin portion 56 and the second fin portion 57 being in contact with both adjacent battery cells 20.

[0070] (1-4) The first fin portion 56 is inclined with respect to the first arrangement direction, and the second fin portion 57 is inclined with respect to the second arrangement direction. As a result, insulation can be ensured by the first fin portion 56 and the second fin portion 57 contacting both adjacent battery cells 20 at different positions.

[0071] (Second Embodiment) A second embodiment of the battery module and spacer will be described below with reference to Figures 6 and 7. The battery module and spacer of this embodiment differ from those of the first embodiment in the space-forming portion. The differences from the first embodiment will be described below.

[0072] (Space forming part 13A) Next, the space-forming portion 13A will be described in detail with reference to Figures 6 and 7. Figures 6 and 7 are cross-sectional views of the space-forming portion 13A of the spacer 13. Figure 6 shows the space-forming portion 13A in an uncompressed state together with the adjacent battery cells 20. Figure 7 shows the space-forming portion 13A in a compressed state together with the adjacent battery cells 20.

[0073] As shown in Figure 6, the bar section 30 has, from top to bottom, a third bar section 33, a first bar section 31, a second bar section 32, and a fourth bar section 34. The distance P1 between the first bar section 31 and the second bar section 32 is longer than the distance P2 between the first bar section 31 and the third bar section 33 and the distance P3 between the second bar section 32 and the fourth bar section 34 (P1 > P2, P1 > P3). The constraint range PX of the electrode body within the battery cell 20 is the range from the upper surface of the third bar section 33 to the lower surface of the fourth bar section 34. The distance P1 is preferably 35 to 60% of the constraint range PX of the electrode body in the direction of arrangement of the surface 21 of the battery cell 20. The fin section 35 has a first fin section 36, a second fin section 37, a third fin section 38, and a fourth fin section 39.

[0074] The first bar portion 31 is provided with a first fin portion 36 and a second fin portion 37. The first fin portion 36 is formed extending in a first orthogonal direction (to the right in the figure) perpendicular to the arrangement direction (Z direction), at a first angle θA inclined with respect to the first arrangement direction (upward direction) in the arrangement direction (Z direction) in which the bar portions 30 are arranged. The second fin portion 37 is formed extending in a first orthogonal direction (to the right in the figure) at a second angle θB inclined with respect to the second arrangement direction (downward direction) opposite to the first arrangement direction. The first fin portion 36 and the second fin portion 37 are in contact with the surface 21 of the first battery cell 20A on the right side in the figure. The first angle θA and the second angle θB are different angles. The first angle θA is a larger angle than the second angle θB.

[0075] The second bar portion 32 is provided with a third fin portion 38 and a fourth fin portion 39. The third fin portion 38 is formed extending in the second orthogonal direction (left direction in the figure), opposite to the first orthogonal direction (right direction in the figure), at a third angle θC with respect to the second alignment direction (downward). The fourth fin portion 39 is formed extending in the second orthogonal direction (left direction in the figure), at a fourth angle θD with respect to the first alignment direction (upward). The third fin portion 38 and the fourth fin portion 39 are in contact with the surface 21 of the second battery cell 20B on the left side in the figure. The third angle θC and the fourth angle θD are different angles. The third angle θC is a larger angle than the fourth angle θD. The first angle θA and the third angle θC are the same angle. The second angle θB and the fourth angle θD are the same angle.

[0076] A third fin portion 38 is provided on the third bar portion 33. The third fin portion 38 is formed extending in the second orthogonal direction (left direction in the figure) at a third angle θC with respect to the second alignment direction (downward direction). The third fin portion 38 is in contact with the left side surface 21 of the second battery cell 20B.

[0077] The fourth bar portion 34 is provided with a first fin portion 36. The first fin portion 36 is formed extending in a first orthogonal direction (to the right in the figure) at a first angle θA inclined with respect to the first arrangement direction (upward direction). The first fin portion 36 is in contact with the surface 21 of the right-side first battery cell 20A.

[0078] (Uncompressed state) As shown in FIG. 6, in the uncompressed state, the tips of the first fin portion 36 and the second fin portion 37 provided on the first bar portion 31 protrude toward the first battery cell 20A side on the right side in the figure rather than the first bar portion 31. Further, in the uncompressed state, the tips of the third fin portion 38 and the fourth fin portion 39 provided on the second bar portion 32 protrude toward the second battery cell 20B side on the left side rather than the second bar portion 32. The tip of the third fin portion 38 provided on the third bar portion 33 protrudes toward the second battery cell 20B side on the left side rather than the third bar portion 33. The tip of the first fin portion 36 provided on the fourth bar portion 34 protrudes toward the first battery cell 20A side on the right side rather than the fourth bar portion 34. The first bar portion 31, the second bar portion 32, the third bar portion 33, and the fourth bar portion 34 do not contact either the surface 21 of the first battery cell 20A on the right side or the surface 21 of the second battery cell 20B on the left side.

[0079] The first fin length LA, which is the length of the first fin portion 36 from the first bar portion 31, and the third fin length LC, which is the length of the third fin portion 38 from the third bar portion 33, are both shorter than the distance P2 between the first bar portion 31 and the third bar portion 33 (LA < P2, LC < P2). The first fin length LA and the third fin length LC are the same length (LA = LC). The sum of the first fin length LA and the third fin length LC is longer than the distance P2 between the first bar portion 31 and the third bar portion 33 (LA + LC > P2).

[0080] The second fin length LB, which is the length of the second fin portion 37 from the first bar portion 31, and the fourth fin length LD, which is the length of the fourth fin portion 39 from the second bar portion 32, are both shorter than the distance P1 between the first bar portion 31 and the second bar portion 32 (LB < P1, LD < P1). The second fin length LB and the fourth fin length LD are the same length (LB = LD). The sum of the second fin length LB and the fourth fin length LD is longer than the distance P1 between the first bar portion 31 and the second bar portion 32 (LB + LD > P1). The second fin length LB, which is the length of the second fin portion 37 from the first bar portion 31, is longer than the first fin length LA, which is the length of the first fin portion 36 from the first bar portion 31 (LB > LA).

[0081] The third fin length LC, which is the length from the second bar portion 32 of the third fin portion 38, and the first fin length LA, which is the length from the fourth bar portion 34 of the first fin portion 36, are both shorter than the interval P3 between the second bar portion 32 and the fourth bar portion 34 (LC < P3, LA < P3). The third fin length LC and the first fin length LA are of the same length (LC = LA). The sum of the third fin length LC and the first fin length LA is longer than the interval P3 between the second bar portion 32 and the fourth bar portion 34 (LC + LA > P3). The fourth fin length LD, which is the length from the second bar portion 32 of the fourth fin portion 39, is longer than the third fin length LC, which is the length from the second bar portion 32 of the third fin portion 38 (LD > LC).

[0082] The sum of the projection lengths LZA in the arrangement direction (Z direction) of the first fin portion 36 and the projection length LZC in the arrangement direction (Z direction) of the third fin portion 38 is shorter than the interval P2 between the first bar portion 31 and the third bar portion 33 in the non-compressed state (LZA + LZC < P2). Therefore, in the non-compressed state, a gap G2 is provided in the arrangement direction (Z direction) between the tips of the first fin portion 36 and the third fin portion 38. As a result, the first fin portion 36 and the third fin portion 38 are prevented from overlapping in the arrangement direction (Z direction). Such a spacer 13 can be manufactured at a low cost.

[0083] The sum of the projection lengths LZB in the arrangement direction (Z direction) of the second fin portion 37 and the projection length LZD in the arrangement direction (Z direction) of the fourth fin portion 39 is shorter than the interval P1 between the first bar portion 31 and the second bar portion 32 in the non-compressed state (LZB + LZD < P1). Therefore, in the non-compressed state, a gap G1 is provided in the arrangement direction (Z direction) between the tips of the second fin portion 37 and the fourth fin portion 39. As a result, the second fin portion 37 and the fourth fin portion 39 are prevented from overlapping in the arrangement direction (Z direction). Such a spacer 13 can be manufactured at a low cost.

[0084] The sum of the projected length LZC in the arrangement direction (Z direction) of the third fin portion 38 and the projected length LZA in the arrangement direction (Z direction) of the first fin portion 36 is shorter than the distance P3 between the second bar portion 32 and the fourth bar portion 34 in the non-compressed state (LZC + LZA < P3). Therefore, in the non-compressed state, a gap G3 is provided in the arrangement direction (Z direction) between the tips of the third fin portion 38 and the first fin portion 36. As a result, the third fin portion 38 and the first fin portion 36 do not overlap in the arrangement direction (Z direction). Such a spacer 13 can be manufactured at a low cost.

[0085] (Compressed state) As shown in FIG. 7, in the compressed state, the right side surface of the bar portion 30 is in contact with the surface 21 of the right first battery cell 20A. The surface 21 of the left second battery cell 20B is in contact with the left side surface of the bar portion 30. That is, in the compressed state, the bar portion 30 is sandwiched between the surface 21 of the first battery cell 20A and the surface 21 of the second battery cell 20B, and is compressed in the stacking direction (X direction). Further, the bar portion 30 presses the surface 21 of the first battery cell 20A and the surface 21 of the second battery cell 20B in a direction away from each other by the reaction force against the compression. As a result, the contact between the adjacent battery cells 20 is suppressed by the bar portion 30. And a space 15 is formed between the two bar portions 30 adjacent to each other vertically, in which the surfaces 21 of the battery cells 20 adjacent to both sides of the spacer 13 are separated from each other.

[0086] Since the surface 21 of the right first battery cell 20A is in contact with the right side surface of the first bar portion 31, the first fin portion 36 provided on the first bar portion 31 is pressed to the left by the surface 21 of the right first battery cell 20A. By this pressing, the first fin portion 36 is in a state of being bent to the left more than in the non-compressed state along the surface 21 of the right first battery cell 20A. The bent first fin portion 36 extends upward along the surface 21 of the right first battery cell 20A. And the bent first fin portion 36 presses the surface 21 of the right first battery cell 20A to the right by the reaction force of the bending.

[0087] As the right side surface of the first bar portion 31 is in contact with the surface 21 of the right first battery cell 20A, the second fin portion 37 provided on the first bar portion 31 is pressed to the left by the surface 21 of the right first battery cell 20A. Due to this pressure, the second fin portion 37 is bent to the left along the surface 21 of the right first battery cell 20A compared to when it is uncompressed. In this bent state, the second fin portion 37 extends downward along the surface 21 of the right first battery cell 20A. Then, due to the reaction force of its bending, the bent second fin portion 37 presses the surface 21 of the right first battery cell 20A to the right.

[0088] The left side of the second bar portion 32 is in contact with the left side surface 21 of the second battery cell 20B, causing the third fin portion 38 provided on the second bar portion 32 to be pressed to the right by the left side surface 21 of the second battery cell 20B. Due to this pressure, the third fin portion 38 is bent to the right along the left side surface 21 of the second battery cell 20B compared to when it is uncompressed. In this bent state, the third fin portion 38 extends downward along the left side surface 21 of the second battery cell 20B. The reaction force of this bending then presses the left side surface 21 of the second battery cell 20B to the left.

[0089] As the left side surface of the second bar portion 32 is in contact with the left side surface 21 of the second battery cell 20B, the fourth fin portion 39 provided on the second bar portion 32 is pressed to the right by the left side surface 21 of the second battery cell 20B. Due to this pressure, the fourth fin portion 39 is bent to the right along the left side surface 21 of the second battery cell 20B compared to when it is uncompressed. In this bent state, the fourth fin portion 39 extends upward along the left side surface 21 of the second battery cell 20B. Furthermore, the reaction force of this bending presses the left side surface 21 of the second battery cell 20B to the left.

[0090] The left side of the third bar portion 33 is in contact with the left side surface 21 of the left second battery cell 20B, causing the third fin portion 38 provided on the third bar portion 33 to be pressed to the right by the left side surface 21 of the second battery cell 20B. Due to this pressure, the third fin portion 38 is bent to the right along the left side surface 21 of the second battery cell 20B compared to when it is uncompressed. In this bent state, the third fin portion 38 extends downward along the left side surface 21 of the second battery cell 20B. The reaction force of this bending then presses the left side surface 21 of the second battery cell 20B to the left.

[0091] The right side of the fourth bar portion 34 is in contact with the surface 21 of the right first battery cell 20A, causing the first fin portion 36 provided on the fourth bar portion 34 to be pressed to the left by the surface 21 of the right first battery cell 20A. Due to this pressure, the first fin portion 36 is bent to the left along the surface 21 of the right first battery cell 20A compared to when it is uncompressed. In this bent state, the first fin portion 36 extends upward along the surface 21 of the right first battery cell 20A. The reaction force of this bending then presses the surface 21 of the right first battery cell 20A to the right.

[0092] As mentioned above, the first fin length LA of the first fin portion 36 and the third fin length LC of the third fin portion 38 are both shorter than the distance P2 between the first bar portion 31 and the third bar portion 33. Therefore, on the right side of the first battery cell 20A, there is a portion on the surface 21 that is not covered by the first fin portion 36 at the distance P2 between the first bar portion 31 and the third bar portion 33. Also, on the left side of the second battery cell 20B, there is a portion on the surface 21 that is not covered by the third fin portion 38 at the distance P3 between the first bar portion 31 and the third bar portion 33.

[0093] Similarly, the second fin length LB of the second fin portion 37 and the fourth fin length LD of the fourth fin portion 39 are both shorter than the distance P1 between the first bar portion 31 and the second bar portion 32. As a result, on the right side of the first battery cell 20A, there is a portion of the surface 21 that is not covered by the second fin portion 37 at the distance P1 between the first bar portion 31 and the second bar portion 32. Also, on the left side of the second battery cell 20B, there is a portion of the surface 21 that is not covered by the fourth fin portion 39 at the distance P1 between the first bar portion 31 and the second bar portion 32.

[0094] Similarly, the third fin length LC of the third fin portion 38 and the first fin length LA of the first fin portion 36 are both shorter than the distance P3 between the second bar portion 32 and the fourth bar portion 34. As a result, on the left side of the second battery cell 20B, there is a portion of the surface 21 that is not covered by the third fin portion 38 at the distance P3 between the second bar portion 32 and the fourth bar portion 34. Also, on the right side of the first battery cell 20A, there is a portion of the surface 21 that is not covered by the first fin portion 36 at the distance P3 between the second bar portion 32 and the fourth bar portion 34.

[0095] Therefore, the surfaces 21 of the battery cells 20 adjacent to the spacer 13 have portions exposed to the space 15 in the gap between the bar portions 30. In other words, when the battery cells 20 adjacent to the spacer 13 generate heat, they can dissipate heat into the space 15. The space 15 is the passage path for the cooling gas used to cool the battery cells 20 in the battery module 10. As a result, the spacer 13 can cool the battery cells 20 adjacent to it while suppressing a large temperature difference between the two adjacent battery cells 20.

[0096] Furthermore, as mentioned above, the sum of the first fin length LA of the first fin portion 36 and the third fin length LC of the third fin portion 38 is longer than the distance P2 between the first bar portion 31 and the third bar portion 33. Therefore, in the compressed state, the first fin portion 36 and the third fin portion 38 overlap in the alignment direction (Z direction). In other words, there is an overlap L2 between the tip of the first fin portion 36 and the tip of the third fin portion 38. Thus, the first fin portion 36 presses at least the area of ​​the right-side first battery cell 20A that is opposite to the area of ​​the left-side second battery cell 20B that is not being pressed by the third fin portion 38. The third fin portion 38 presses at least the area of ​​the left-side second battery cell 20B that is opposite to the area of ​​the right-side first battery cell 20A that is not being pressed by the first fin portion 36. In other words, the battery cells 20 adjacent to the spacer 13 have no gap in the arrangement direction (Z direction) at the distance P2 between the first bar portion 31 and the third bar portion 33, and are pressed in a direction away from at least one of the first fin portion 36 and the third fin portion 38. Furthermore, the battery cells 20 adjacent to the spacer 13 do not come into contact with each other between the first bar portion 31 and the third bar portion 33. For example, even if the adjacent battery cells 20 expand and enter the space 15 while bending the first fin portion 36 and the third fin portion 38 respectively, at least one of the first fin portion 36 and the third fin portion 38 will always be present between the adjacent battery cells 20. As a result, the spacer 13 can reliably maintain insulation between the adjacent battery cells 20.

[0097] Similarly, the sum of the second fin length LB of the second fin section 37 and the fourth fin length LD of the fourth fin section 39 is longer than the distance P1 between the first bar section 31 and the second bar section 32. Therefore, in the compressed state, the second fin section 37 and the fourth fin section 39 overlap in the alignment direction (Z direction). In other words, there is an overlap L1 between the tip of the second fin section 37 and the tip of the fourth fin section 39. Thus, the second fin section 37 presses at least the area of ​​the right-side first battery cell 20A that is opposite to the area of ​​the left-side second battery cell 20B that is not being pressed by the fourth fin section 39. The fourth fin section 39 presses at least the area of ​​the left-side second battery cell 20B that is opposite to the area of ​​the right-side first battery cell 20A that is not being pressed by the second fin section 37. In other words, the battery cells 20 adjacent to the spacer 13 have no gap in the arrangement direction (Z direction) at the distance P1 between the first bar portion 31 and the second bar portion 32, and are pressed away from each other by at least one of the second fin portion 37 and the fourth fin portion 39. Furthermore, the battery cells 20 adjacent to the spacer 13 do not come into contact with each other between the first bar portion 31 and the second bar portion 32. For example, even if the adjacent battery cells 20 expand and enter the space 15 while bending the second fin portion 37 and the fourth fin portion 39 respectively, at least one of the second fin portion 37 and the fourth fin portion 39 will always be present between the adjacent battery cells 20. As a result, the spacer 13 can reliably maintain insulation between the adjacent battery cells 20.

[0098] Similarly, the sum of the third fin length LC of the third fin portion 38 and the first fin length LA of the first fin portion 36 is longer than the distance P3 between the second bar portion 32 and the fourth bar portion 34. Therefore, in the compressed state, the third fin portion 38 and the first fin portion 36 overlap in the alignment direction (Z direction). In other words, there is an overlap L3 between the tip of the third fin portion 38 and the tip of the first fin portion 36. Thus, the first fin portion 36 presses at least the region of the right-side first battery cell 20A that is opposite to the region of the left-side second battery cell 20B that is not being pressed by the third fin portion 38. The third fin portion 38 presses at least the region of the left-side second battery cell 20B that is opposite to the region of the right-side first battery cell 20A that is not being pressed by the first fin portion 36. In other words, the battery cells 20 adjacent to the spacer 13 have no gap in the arrangement direction (Z direction) at the distance P3 between the second bar portion 32 and the fourth bar portion 34, and are pressed away from each other by at least one of the first fin portion 36 and the third fin portion 38. Furthermore, the battery cells 20 adjacent to the spacer 13 do not come into contact with each other between the second bar portion 32 and the fourth bar portion 34. For example, even if the adjacent battery cells 20 expand and enter the space 15 while bending the third fin portion 38 and the first fin portion 36 respectively, at least one of the third fin portion 38 and the first fin portion 36 will always be present between the adjacent battery cells 20. As a result, the spacer 13 can reliably maintain insulation between the adjacent battery cells 20.

[0099] As shown in Figure 7, when the spacer 13 is sandwiched between the surfaces 21 of the adjacent battery cells 20, the battery cell 20 is pressed by the bar portion 30. The distance P1 between the first bar portion 31 and the second bar portion 32 near the center in the arrangement direction is wider than the distance P2 between the first bar portion 31 and the third bar portion 33 and the distance P3 between the second bar portion 32 and the fourth bar portion 34, which are not near the center. Therefore, when the battery cell 20 is pressed by the bar portion 30, the pressure on the battery cell 20 near the center by the bar portion 30 is lower than the pressure on the battery cell 20 outside the center. This makes it possible to suppress the pressure on the center when the battery cell 20 expands due to charging and discharging. For example, if the battery cell 20 is a lithium-ion battery, it is possible to suppress high-rate degradation that occurs when the battery cell 20 is excessively pressed and repeatedly expands and contracts.

[0100] Even if the battery cell 20 expands due to some factor, the spacer 13 can prevent the battery cell 20 from entering the space 15 by pressing the battery cell 20 with the first fin portion 36, the second fin portion 37, the third fin portion 38, and the fourth fin portion 39. In other words, even if the battery cell 20 expands, the spacer 13 can prevent the length of the space 15 in the stacking direction (X direction) from narrowing, thereby ensuring that the space 15 is properly maintained. Therefore, the spacer 13 can prevent the flow rate of the cooling gas flowing through the space 15 from decreasing due to the expansion of the battery cell 20. Thus, the spacer 13 can prevent a decrease in the cooling function of the battery cell 20 by the cooling gas flowing through the space 15.

[0101] Next, the effects of the second embodiment will be described. (2-1) The first fin portion 36 and the second fin portion 37 contact the surface 21 of the first battery cell 20A, thereby ensuring an appropriate distance from the surface 21 of the first battery cell 20A, and the third fin portion 38 and the fourth fin portion 39 contact the surface 21 of the second battery cell 20B, thereby ensuring an appropriate distance from the surface 21 of the second battery cell 20B. As a result, the spacer 13 can ensure an appropriate distance between adjacent battery cells 20. Thus, heat is properly dissipated into the space between the battery cells 20, and the battery cells 20 can be properly cooled. In addition, the distance P1 between the first bar portion 31 and the second bar portion 32 near the center in the arrangement direction is wider than the distance P2 between the first bar portion 31 and the third bar portion 33 and the distance P3 between the second bar portion 32 and the fourth bar portion 34, which are not near the center. Therefore, when the battery cells 20 are pressed by the bar portion 30 of the spacer 13 placed between them, the pressure on the central part of the battery cell 20 by the bar portion 30 is lower than the pressure on other parts of the battery cell 20. This makes it possible to suppress the pressure on the central part when the battery cell 20 expands during charging and discharging.

[0102] (2-2) By widening the spacing of the bar portions 30 closer to the center in the arrangement direction, the pressure on the central part of the battery cell 20 is suppressed, while the second fin portion 37 and the fourth fin portion 39 come into contact with the battery cell 20, thereby suppressing excessive deformation of the battery cell 20.

[0103] (2-3) The first fin portion 36 is provided on the first bar portion 31, and the second fin portion 37 is provided on the second bar portion 32, which is different from the first bar portion 31. In this way, the first bar portion 31 on which the first fin portion 36 is provided and the second bar portion 32 on which the second fin portion 37 is provided can be in separate contact with both adjacent battery cells 20, thereby ensuring insulation.

[0104] (2-4) The first bar portion 31 is provided with a first fin portion 36 inclined with respect to the first arrangement direction and a second fin portion 37 inclined with respect to the second arrangement direction, and the second bar portion 32 is provided with a first fin portion 36 inclined with respect to the first arrangement direction and a second fin portion 37 inclined with respect to the second arrangement direction. As a result, at least two fin portions 35 from each bar portion 30 are in contact with the battery cell 20. Thus, insulation between two adjacent battery cells 20 can be ensured.

[0105] (Third embodiment) A third embodiment of the battery module and spacer will be described below with reference to Figures 8 and 9. The battery module and spacer of this embodiment differ from those of the first embodiment in the space-forming portion. The differences from the first embodiment will be described below.

[0106] (Space forming part 13B) Figures 8 and 9 are cross-sectional views of the space-forming portion 13B of the spacer 13. Figure 8 shows the space-forming portion 13B in an uncompressed state together with the adjacent battery cells 20. Figure 9 shows the space-forming portion 13B in a compressed state together with the adjacent battery cells 20.

[0107] As shown in Figure 8, the bar section 40 has, from top to bottom, a third bar section 43, a first bar section 41, a second bar section 42, and a fourth bar section 44. The distance P1 between the first bar section 41 and the second bar section 42 is longer than the distance P2 between the first bar section 41 and the third bar section 43 and the distance P3 between the second bar section 42 and the fourth bar section 44 (P1 > P2, P1 > P3). The restraint range PX of the electrode body within the battery cell 20 is the range from the upper surface of the third bar section 43 to the lower surface of the fourth bar section 44. The distance P1 is preferably 35-60% of the restraint range PX of the electrode body in the direction of arrangement of the surface 21 of the battery cell 20. The fin section 45 has a first fin section 46A, a first stopper section 46B, a second fin section 47A, a second stopper section 47B, a third fin section 48, and a fourth fin section 49.

[0108] The first bar portion 41 is provided with a first fin portion 46A and a first stopper portion 46B. The first fin portion 46A is formed extending in a first orthogonal direction (to the right in the figure) perpendicular to the arrangement direction (Z direction), at a first angle θA inclined with respect to the first arrangement direction (downward) in the arrangement direction (Z direction) in which the bar portions 40 are arranged. The first stopper portion 46B is formed extending in a second arrangement direction (upward) opposite to the first arrangement direction. The first fin portion 46A is in contact with the surface 21 of the first battery cell 20A on the right side in the figure. Since it is desirable that the first stopper portion 46B does not deform when compressed, it is preferable that the thickness of the first stopper portion 46B is greater than the thickness of the first fin portion 46A.

[0109] The second bar portion 42 is provided with a second fin portion 47A and a second stopper portion 47B. The second fin portion 47A is formed extending in a second orthogonal direction (left direction in the figure) opposite to the first orthogonal direction (right direction in the figure) at a second angle θB with respect to the first alignment direction (downward direction). The second stopper portion 47B is formed extending in the second alignment direction (upward direction). The second fin portion 47A is in contact with the surface 21 of the second battery cell 20B on the left side in the figure. The first angle θA and the second angle θB are the same angle. Since it is desirable that the second stopper portion 47B does not deform when compressed, it is preferable that the thickness of the second stopper portion 47B is greater than the thickness of the second fin portion 47A.

[0110] A third fin portion 48 is provided on the third bar portion 43. The third fin portion 48 is formed extending in the second orthogonal direction (left direction in the figure) at a third angle θC with respect to the first alignment direction (downward direction). The third fin portion 48 is in contact with the surface 21 of the second battery cell 20B on the left side.

[0111] The fourth bar portion 44 is provided with a fourth fin portion 49. The fourth fin portion 49 is formed extending in the second arrangement direction (upward). The fourth fin portion 49 is in contact with the surface 21 of the first battery cell 20A on the right side in the figure.

[0112] (Uncompressed state) As shown in FIG. 8, in the uncompressed state, the tip of the first fin portion 46A provided on the first bar portion 41 protrudes toward the first battery cell 20A side on the right side in the drawing from the first bar portion 41. In the uncompressed state, the tip of the second fin portion 47A provided on the second bar portion 42 protrudes toward the second battery cell 20B side on the left side from the second bar portion 42. In the uncompressed state, the tip of the third fin portion 48 provided on the third bar portion 43 protrudes toward the second battery cell 20B side on the left side from the third bar portion 43. In the uncompressed state, the tip of the fourth fin portion 49 provided on the fourth bar portion 44 protrudes toward the first battery cell 20A side on the right side in the drawing from the fourth bar portion 44. The first bar portion 41, the second bar portion 42, the third bar portion 43, and the fourth bar portion 44 do not contact either the surface 21 of the first battery cell 20A on the right side or the surface 21 of the second battery cell 20B on the left side.

[0113] The first fin length LA, which is the length of the first fin portion 46A from the first bar portion 41, and the second fin length LB, which is the length of the second fin portion 47A from the second bar portion 42, are both shorter than the distance P1 between the first bar portion 41 and the second bar portion 42 (LA < P1, LB < P1). The sum of the first fin length LA and the second fin length LB is longer than the distance P1 between the first bar portion 41 and the second bar portion 42 (LA + LB > P1).

[0114] The third fin length LC, which is the length of the third fin portion 48 from the third bar portion 43, and the fifth fin length LE, which is the length of the first stopper portion 46B from the first bar portion 41, are both shorter than the distance P2 between the first bar portion 41 and the third bar portion 43 (LC < P2, LE < P2). The sum of the third fin length LC and the fifth fin length LE is longer than the distance P2 between the first bar portion 41 and the third bar portion 43 (LC + LE > P2).

[0115] The sixth fin length LF, which is the length from the second bar portion 42 of the second stopper portion 47B, and the fourth fin length LD, which is the length from the fourth bar portion 44 of the fourth fin portion 49, are both shorter than the interval P3 between the second bar portion 42 and the fourth bar portion 44 (LF < P3, LD < P3). The sum of the sixth fin length LF and the fourth fin length LD is longer than the interval P3 between the second bar portion 42 and the fourth bar portion 44 (LF + LD > P3).

[0116] The sum of the projection length LZA in the arrangement direction (Z direction) of the first fin portion 46A and the second fin length LB of the second fin portion 47A is shorter than the interval P1 between the first bar portion 41 and the second bar portion 42 in the non-compressed state (LZA + LB < P1). For this reason, in the non-compressed state, a gap G1 is provided in the arrangement direction (Z direction) between the tips of the first fin portion 46A and the second fin portion 47A. As a result, the first fin portion 46A and the second fin portion 47A are prevented from overlapping in the arrangement direction (Z direction). Such a spacer 13 can be manufactured at a low cost.

[0117] The sum of the projection length LZC in the arrangement direction (Z direction) of the third fin portion 48 and the fifth fin length LE of the first stopper portion 46B is shorter than the interval P2 between the first bar portion 41 and the third bar portion 43 in the non-compressed state (LZC + LE < P2). For this reason, in the non-compressed state, a gap G2 is provided in the arrangement direction (Z direction) between the tips of the third fin portion 48 and the first stopper portion 46B. As a result, the third fin portion 48 and the first stopper portion 46B are prevented from overlapping in the arrangement direction (Z direction). Such a spacer 13 can be manufactured at a low cost.

[0118] The total of the projection length LZD in the array direction (Z direction) of the fourth fin portion 49 and the sixth fin length LF of the second stopper portion 47B is shorter than the distance P3 between the second bar portion 42 and the fourth bar portion 44 in the non-compressed state (LZD + LF < P3). Therefore, in the non-compressed state, a gap G3 is provided in the array direction (Z direction) between the tips of the fourth fin portion 49 and the second stopper portion 47B. As a result, the fourth fin portion 49 and the second stopper portion 47B do not overlap in the array direction (Z direction). Such a spacer 13 can be manufactured at a low cost.

[0119] (Compressed state) As shown in FIG. 9, in the compressed state, the right side surface of the bar portion 40 is in contact with the surface 21 of the right first battery cell 20A. The surface 21 of the left second battery cell 20B is in contact with the left side surface of the bar portion 40. That is, in the compressed state, the bar portion 40 is sandwiched between the surface 21 of the first battery cell 20A and the surface 21 of the second battery cell 20B, and is compressed in the stacking direction (X direction). Further, the bar portion 40 presses the surface 21 of the first battery cell 20A and the surface 21 of the second battery cell 20B in a direction away from each other by the reaction force against the compression. As a result, the contact between the adjacent battery cells 20 on both sides is suppressed by the bar portion 40. And a space 15 is formed between the two bar portions 40 adjacent to each other vertically, in which the surfaces 21 of the battery cells 20 adjacent to both sides of the spacer 13 are separated from each other.

[0120] Since the surface 21 of the right first battery cell 20A is in contact with the right side surface of the first bar portion 41, the first fin portion 46A provided on the first bar portion 41 is pressed to the left by the surface 21 of the right first battery cell 20A. By this pressing, the first fin portion 46A is in a state of being bent to the left more than in the non-compressed state along the surface 21 of the right first battery cell 20A. The bent first fin portion 46A extends downward along the surface 21 of the right first battery cell 20A. And the bent first fin portion 46A presses the surface 21 of the right first battery cell 20A to the right by the reaction force of the bending.

[0121] As the left side surface of the second bar portion 42 is in contact with the left side surface 21 of the second battery cell 20B, the second fin portion 47A provided on the second bar portion 42 is pressed to the right by the left side surface 21 of the second battery cell 20B. Due to this pressure, the second fin portion 47A is bent to the right along the left side surface 21 of the second battery cell 20B compared to when it is uncompressed. In this bent state, the second fin portion 47A extends downward along the left side surface 21 of the second battery cell 20B. Then, due to the reaction force of its bending, the bent second fin portion 47A presses the left side surface 21 of the second battery cell 20B to the left.

[0122] The left side of the third bar portion 43 is in contact with the left side surface 21 of the left second battery cell 20B, causing the third fin portion 48 provided on the third bar portion 43 to be pressed to the right by the left side surface 21 of the second battery cell 20B. Due to this pressure, the third fin portion 48 is bent to the right along the left side surface 21 of the second battery cell 20B compared to when it is uncompressed. In this bent state, the third fin portion 48 extends downward along the left side surface 21 of the second battery cell 20B. The reaction force of this bending then presses the left side surface 21 of the second battery cell 20B to the left.

[0123] As mentioned above, the first fin length LA of the first fin portion 46A and the second fin length LB of the second fin portion 47A are both shorter than the distance P1 between the first bar portion 41 and the second bar portion 42. Therefore, on the right side of the first battery cell 20A, there is a portion of the surface 21 that is not covered by the first fin portion 46A at the distance P1 between the first bar portion 41 and the second bar portion 42. Similarly, on the left side of the second battery cell 20B, there is a portion of the surface 21 that is not covered by the second fin portion 47A at the distance P1 between the first bar portion 41 and the second bar portion 42.

[0124] Similarly, the third fin length LC of the third fin portion 48 and the fifth fin length LE of the first stopper portion 46B are both shorter than the distance P2 between the first bar portion 41 and the third bar portion 43. As a result, on the right side of the first battery cell 20A, there is a portion of the surface 21 that is not covered by the first stopper portion 46B at the distance P2 between the first bar portion 41 and the third bar portion 43. Also, on the left side of the second battery cell 20B, there is a portion of the surface 21 that is not covered by the third fin portion 48 at the distance P2 between the first bar portion 41 and the third bar portion 43.

[0125] Similarly, the sixth fin length LF of the second stopper portion 47B and the fourth fin length LD of the fourth fin portion 49 are both shorter than the distance P3 between the second bar portion 42 and the fourth bar portion 44. As a result, on the left side of the second battery cell 20B, there is a portion of the surface 21 that is not covered by the second stopper portion 47B at the distance P3 between the second bar portion 42 and the fourth bar portion 44. Also, on the right side of the first battery cell 20A, there is a portion of the surface 21 that is not covered by the fourth fin portion 49 at the distance P3 between the second bar portion 42 and the fourth bar portion 44.

[0126] Therefore, the surfaces 21 of the battery cells 20 adjacent to the spacer 13 have portions exposed to the space 15 in the gap between the bar portions 40. In other words, when the battery cells 20 adjacent to the spacer 13 generate heat, they can dissipate heat into the space 15. The space 15 is the passage path for the cooling gas used to cool the battery cells 20 in the battery module 10. As a result, the spacer 13 can cool the battery cells 20 adjacent to it while suppressing a large temperature difference between the two adjacent battery cells 20.

[0127] Furthermore, as mentioned above, the sum of the fifth fin length LE of the first stopper portion 46B and the third fin length LC of the third fin portion 48 is longer than the distance P2 between the first bar portion 41 and the third bar portion 43. Therefore, in the compressed state, the first stopper portion 46B and the third fin portion 48 overlap in the alignment direction (Z direction). In other words, there is an overlap L2 between the tip of the first stopper portion 46B and the tip of the third fin portion 48. Thus, the first stopper portion 46B presses at least the area of ​​the right-side first battery cell 20A that is opposite to the area of ​​the left-side second battery cell 20B that is not being pressed by the third fin portion 48. The third fin portion 48 presses at least the area of ​​the left-side second battery cell 20B that is opposite to the area of ​​the right-side first battery cell 20A that is not being pressed by the first stopper portion 46B. In other words, the battery cells 20 adjacent to the spacer 13 have no gap in the arrangement direction (Z direction) at the distance P2 between the first bar portion 41 and the third bar portion 43, and are pressed away from each other by at least one of the first stopper portion 46B and the third fin portion 48. Furthermore, the battery cells 20 adjacent to the spacer 13 do not come into contact with each other between the first bar portion 41 and the third bar portion 43. For example, even if the adjacent battery cells 20 expand and enter the space 15 while bending the first stopper portion 46B and the third fin portion 48 respectively, at least one of the first stopper portion 46B and the third fin portion 48 will always be present between the adjacent battery cells 20. As a result, the spacer 13 can reliably maintain insulation between the adjacent battery cells 20.

[0128] Similarly, the sum of the first fin length LA of the first fin portion 46A and the third fin length LC of the second fin portion 47A is longer than the distance P1 between the first bar portion 41 and the second bar portion 42. Therefore, in the compressed state, the first fin portion 46A and the second fin portion 47A overlap in the alignment direction (Z direction). In other words, there is an overlap L1 between the tip of the first fin portion 46A and the tip of the second fin portion 47A. Thus, the first fin portion 46A presses on at least the region of the right-side first battery cell 20A that is opposite to the region of the left-side second battery cell 20B that is not being pressed by the second fin portion 47A. The second fin portion 47A presses on at least the region of the left-side second battery cell 20B that is opposite to the region of the right-side first battery cell 20A that is not being pressed by the first fin portion 46A. In other words, the battery cells 20 adjacent to the spacer 13 have no gap in the arrangement direction (Z direction) at the distance P1 between the first bar portion 41 and the second bar portion 42, and are pressed in a direction away from at least one of the first fin portion 46A and the second fin portion 47A. Furthermore, the battery cells 20 adjacent to the spacer 13 do not come into contact with each other between the first bar portion 41 and the second bar portion 42. For example, even if the adjacent battery cells 20 expand and enter the space 15 while bending the first fin portion 46A and the second fin portion 47A respectively, at least one of the first fin portion 46A and the second fin portion 47A will always be present between the adjacent battery cells 20. As a result, the spacer 13 can reliably maintain insulation between the adjacent battery cells 20.

[0129] Similarly, the sum of the sixth fin length LF of the second stopper portion 47B and the fourth fin length LD of the fourth fin portion 49 is longer than the distance P3 between the second bar portion 42 and the fourth bar portion 44. Therefore, in the compressed state, the second stopper portion 47B and the fourth fin portion 49 overlap in the alignment direction (Z direction). In other words, there is an overlap L3 between the tip of the second stopper portion 47B and the tip of the fourth fin portion 49. Thus, the second stopper portion 47B presses on at least the area of ​​the right-side first battery cell 20A that is opposite to the area of ​​the left-side second battery cell 20B that is not being pressed by the fourth fin portion 49. The fourth fin portion 49 presses on at least the area of ​​the left-side second battery cell 20B that is opposite to the area of ​​the right-side first battery cell 20A that is not being pressed by the second stopper portion 47B. In other words, the battery cells 20 adjacent to the spacer 13 have no gap in the arrangement direction (Z direction) at the distance P3 between the second bar portion 42 and the fourth bar portion 44, and are pressed away from each other by at least one of the second stopper portion 47B and the fourth fin portion 49. Furthermore, the battery cells 20 adjacent to the spacer 13 do not come into contact with each other between the second bar portion 42 and the fourth bar portion 44. For example, even if the adjacent battery cells 20 expand and enter the space 15 while bending the second stopper portion 47B and the fourth fin portion 49 respectively, at least one of the second stopper portion 47B and the fourth fin portion 49 will always be present between the adjacent battery cells 20. As a result, the spacer 13 can reliably maintain insulation between the adjacent battery cells 20.

[0130] As shown in Figure 9, when the spacer 13 is sandwiched between the surfaces 21 of the adjacent battery cells 20, the battery cell 20 is pressed by the bar portion 40. The distance P1 between the first bar portion 41 and the second bar portion 42 near the center in the arrangement direction is wider than the distance P2 between the first bar portion 41 and the third bar portion 43 and the distance P3 between the second bar portion 42 and the fourth bar portion 44, which are not near the center. Therefore, when the battery cell 20 is pressed by the bar portion 40, the pressure on the battery cell 20 near the center by the bar portion 40 is lower than the pressure on the battery cell 20 outside the center. This makes it possible to suppress the pressure on the center when the battery cell 20 expands due to charging and discharging. For example, if the battery cell 20 is a lithium-ion battery, it is possible to suppress high-rate degradation that occurs when the battery cell 20 is excessively pressed and repeatedly expands and contracts.

[0131] Even if the battery cell 20 expands due to some factor, the spacer 13 can prevent the battery cell 20 from entering the space 15 by pressing the battery cell 20 with the first fin portion 46A, the first stopper portion 46B, the second fin portion 47A, the second stopper portion 47B, the third fin portion 48, and the fourth fin portion 49. In other words, even if the battery cell 20 expands, the spacer 13 can prevent the length of the space 15 in the stacking direction (X direction) from narrowing, thereby ensuring that the space 15 is properly maintained. As a result, the spacer 13 can prevent the flow rate of the cooling gas flowing through the space 15 from decreasing due to the expansion of the battery cell 20. Thus, the spacer 13 can prevent a decrease in the cooling function of the battery cell 20 by the cooling gas flowing through the space 15.

[0132] Next, the effects of the third embodiment will be described. (3-1) The first fin portion 46A and the first stopper portion 46B contact the surface 21 of the first battery cell 20A, thereby ensuring an appropriate distance from the surface 21 of the first battery cell 20A, and the second fin portion 47A and the second stopper portion 47B contact the surface 21 of the second battery cell 20B, thereby ensuring an appropriate distance from the surface 21 of the second battery cell 20B. As a result, the spacer 13 can ensure an appropriate distance between adjacent battery cells 20. Thus, heat is properly dissipated into the space 15 between the battery cells 20, and the battery cells 20 can be properly cooled. In addition, the distance P1 between the first bar portion 41 and the second bar portion 42 near the center in the arrangement direction is wider than the distance P2 between the first bar portion 41 and the third bar portion 43 and the distance P3 between the second bar portion 42 and the fourth bar portion 44, which are not near the center. Therefore, when the battery cells 20 are pressed by the bar portion 40 of the spacer 13 placed between them, the pressure on the central part of the battery cell 20 by the bar portion 40 is lower than the pressure on other parts of the battery cell 20. This makes it possible to suppress the pressure on the central part when the battery cell 20 expands during charging and discharging.

[0133] (3-2) By widening the spacing of the bar portions 40 closer to the center in the arrangement direction, the pressure on the central part of the battery cell 20 is suppressed, while the first fin portion 46A and the second fin portion 47A come into contact with the battery cell 20, thereby suppressing excessive deformation of the battery cell 20.

[0134] (3-3) The first fin portion 46A is provided on the first bar portion 41, and the second fin portion 47A is provided on the second bar portion 42, which is different from the first bar portion 41. In this way, insulation can be ensured as the first bar portion 41, on which the first fin portion 46A is provided, and the second bar portion 42, on which the second fin portion 47A is provided, are in separate contact with both adjacent battery cells 20.

[0135] (3-4) The first bar portion 41 is provided with a first fin portion 46A inclined with respect to the first arrangement direction and a first stopper portion 46B extending in the second arrangement direction, and the second bar portion 42 is provided with a second fin portion 47A inclined with respect to the second arrangement direction and a second stopper portion 47B extending in the first arrangement direction. As a result, at least the fin portion and the stopper portion from each bar portion 40 are in contact with the battery cell 20. Thus, insulation between two adjacent battery cells 20 can be ensured.

[0136] (Fourth Embodiment) A fourth embodiment of the battery module and spacer will be described below with reference to Figures 10 and 11. The battery module and spacer of this embodiment differ from those of the first embodiment in the space-forming portion. The differences from the first embodiment will be described below.

[0137] (Space forming part 13C) Next, the space-forming portion 13C will be described in detail with reference to Figures 10 and 11. Figures 10 and 11 are cross-sectional views of the space-forming portion 13C of the spacer 13. Figure 10 shows the space-forming portion 13C in an uncompressed state together with the adjacent battery cells 20. Figure 11 shows the space-forming portion 13C in a compressed state together with the adjacent battery cells 20.

[0138] (Uncompressed state) As shown in Figure 10, the bar section 50 has, from top to bottom, a third bar section 53, a first bar section 51, a second bar section 52, and a fourth bar section 54. The spacing of the bar sections 50 closer to the bottom surface in the arrangement direction is wider than the spacing of the bar sections 50 further away from the bottom surface. That is, the spacing P6 between the second bar section 52 and the fourth bar section 54 is longer than the spacing P5 between the first bar section 51 and the third bar section 53 and the spacing P4 between the first bar section 51 and the second bar section 52 (P6>P5, P6>P4). The spacing P6 is preferably 35-60% of the constraint range PX of the electrode body in the arrangement direction of the surface 21 of the battery cell 20. The fin section 55 has a first fin section 56, a second fin section 57, a third fin section 58, and a fourth fin section 59.

[0139] The first bar portion 51 is provided with a first fin portion 56 and a third fin portion 58. The first fin portion 56 is formed extending in a first orthogonal direction (to the right in the figure) perpendicular to the arrangement direction (Z direction), at a first angle θA with respect to the first arrangement direction (upward direction) in the arrangement direction (Z direction) in which the bar portions 50 are arranged. The third fin portion 58 is formed extending in a second orthogonal direction (to the left in the figure) opposite to the first orthogonal direction, at a third angle θC with respect to the second arrangement direction (downward direction) opposite to the first arrangement direction. The first fin portion 56 is in contact with the surface 21 of the first battery cell 20A on the right side in the figure. The third fin portion 58 is in contact with the surface 21 of the second battery cell 20B on the left side in the figure. The first angle θA and the third angle θC are the same angle.

[0140] The second bar portion 52 is provided with a first fin portion 56 and a second fin portion 57. The first fin portion 56 is formed extending in a first orthogonal direction (to the right in the figure) at a first angle θA inclined with respect to the first arrangement direction (upward direction). The second fin portion 57 is formed extending in a second orthogonal direction (to the left in the figure) perpendicular to the arrangement direction (Z direction) at a second angle θB inclined with respect to the second arrangement direction (downward direction). The first fin portion 56 is in contact with the surface 21 of the first battery cell 20A on the right side in the figure. The second fin portion 57 is in contact with the surface 21 of the second battery cell 20B on the left side in the figure. The first angle θA and the second angle θB are different angles. The first angle θA is a larger angle than the second angle θB.

[0141] A third fin portion 58 is provided on the third bar portion 53. The third fin portion 58 is formed extending in the second orthogonal direction (left direction in the figure) at a third angle θC with respect to the second alignment direction (downward direction). The third fin portion 58 is in contact with the surface 21 of the second battery cell 20B on the left side.

[0142] The fourth bar portion 54 is provided with a fourth fin portion 59. The fourth fin portion 59 is formed extending in the first orthogonal direction (to the right in the figure) at a fourth angle θD with respect to the first arrangement direction (upward). The first fin portion 56 is in contact with the surface 21 of the first battery cell 20A on the right side. The second angle θB and the fourth angle θD are the same angle.

[0143] At interval P5, in the uncompressed state, a gap G5 is provided between the tips of the first fin portion 56 and the third fin portion 58 in the direction of arrangement (Z direction). At interval P4, in the uncompressed state, a gap G4 is provided between the tips of the first fin portion 56 and the third fin portion 58 in the direction of arrangement (Z direction). At interval P6, in the uncompressed state, a gap G6 is provided between the tips of the second fin portion 57 and the fourth fin portion 59 in the direction of arrangement (Z direction).

[0144] (Compressed state) As shown in Figure 11, the second fin length LB, which is the length of the second fin portion 57 from the second bar portion 52, is longer than the third fin length LC, which is the length of the third fin portion 58 from the first bar portion 51 or the third bar portion 53 (LB>LC). The fourth fin length LD, which is the length of the fourth fin portion 59 from the fourth bar portion 54, is longer than the first fin length LA, which is the length of the first fin portion 56 from the first bar portion 51 or the second bar portion 52 (LB>LA).

[0145] At interval P5, in the compressed state, the first fin portion 56 and the third fin portion 58 overlap in the alignment direction (Z direction). In other words, there is an overlap L5 between the tip of the first fin portion 56 and the tip of the third fin portion 58. At interval P4, in the compressed state, the third fin portion 58 and the first fin portion 56 overlap in the alignment direction (Z direction). In other words, there is an overlap L4 between the tip of the third fin portion 58 and the tip of the first fin portion 56. At interval P6, in the compressed state, the second fin portion 57 and the fourth fin portion 59 overlap in the alignment direction (Z direction). In other words, there is an overlap L6 between the tip of the second fin portion 57 and the tip of the fourth fin portion 59.

[0146] As shown in Figure 11, when the spacer 13 is sandwiched between the surfaces 21 of the adjacent battery cells 20, the battery cell 20 is pressed by the bar portion 50. The distance P6 between the second bar portion 52 and the fourth bar portion 54 near the bottom in the arrangement direction is wider than the distance P5 between the first bar portion 51 and the third bar portion 53 and the distance P4 between the first bar portion 51 and the second bar portion 52, which are not near the bottom. Therefore, when the battery cell 20 is pressed by the bar portion 50, the pressure on the battery cell 20 near the bottom by the bar portion 50 is lower than on the battery cell 20 in other areas. This makes it possible to suppress the pressure on the bottom when the battery cell 20 expands due to charging and discharging. This is particularly effective when the electrolyte accumulates near the bottom. For example, if the battery cell 20 is a lithium-ion battery, it is possible to suppress high-rate degradation that occurs when the battery cell 20 is excessively pressed and repeatedly expands and contracts.

[0147] Even if the battery cell 20 expands due to some factor, the spacer 13 can prevent the battery cell 20 from entering the space 15 by pressing the battery cell 20 with the first fin portion 56, second fin portion 57, third fin portion 58, and fourth fin portion 59. In other words, even if the battery cell 20 expands, the spacer 13 can prevent the length of the space 15 in the stacking direction (X direction) from narrowing, thereby ensuring that the space 15 is properly maintained. Therefore, the spacer 13 can prevent the flow rate of the cooling gas flowing through the space 15 from decreasing due to the expansion of the battery cell 20. Thus, the spacer 13 can prevent a decrease in the cooling function of the battery cell 20 by the cooling gas flowing through the space 15.

[0148] Next, the effects of the fourth embodiment will be described. (4-1) The first fin portion 56 and the fourth fin portion 59 contact the surface 21 of the first battery cell 20A, thereby ensuring an appropriate distance from the surface 21 of the first battery cell 20A, and the second fin portion 57 and the third fin portion 58 contact the surface 21 of the second battery cell 20B, thereby ensuring an appropriate distance from the surface 21 of the second battery cell 20B. As a result, the spacer 13 can ensure an appropriate distance between adjacent battery cells 20. Thus, heat is properly dissipated into the space between the battery cells 20, and the battery cells 20 can be properly cooled. In addition, the spacing P6 between the second bar portion 52 and the fourth bar portion 54 near the bottom in the arrangement direction is wider than the spacing P5 between the first bar portion 51 and the third bar portion 53 and the spacing P4 between the first bar portion 51 and the second bar portion 52, which are not near the bottom. Therefore, when the battery cells 20 are pressed by the bar portion 50 of the spacer 13 placed between them, the pressure on the bottom of the battery cell 20 by the bar portion 50 is lower than the pressure on other parts of the battery cell 20. This makes it possible to suppress the pressure on the bottom when the battery cell 20 expands during charging and discharging.

[0149] (4-2) By widening the spacing of the bar portions 50 near the bottom in the arrangement direction, the pressure on the bottom of the battery cell 20 is suppressed, while the second fin portion 57 and the fourth fin portion 59 come into contact with the battery cell 20, thereby suppressing excessive deformation of the battery cell 20.

[0150] (4-3) The same bar portion 50 is provided with a first fin portion 56 and a second fin portion 57. Therefore, insulation can be ensured by the first fin portion 56 and the second fin portion 57 being in contact with both adjacent battery cells 20.

[0151] (4-4) The first fin portion 56 is inclined with respect to the first arrangement direction, and the second fin portion 57 is inclined with respect to the second arrangement direction. As a result, insulation can be ensured by the first fin portion 56 and the second fin portion 57 contacting both adjacent battery cells 20 at different positions.

[0152] (Other embodiments) Each of the above embodiments can be implemented with the following modifications. Each of the above embodiments and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0153] In each of the above embodiments, four bar sections are provided. However, five or more bar sections may be provided. Furthermore, wide-spaced bar sections may be provided in 35-60% of the restraint range PX of the electrode body within the battery cell 20, and narrow-spaced bar sections may be provided in the remaining areas.

[0154] In the second and third embodiments described above, the spacing between the bars near the center in the arrangement direction was made wider than the spacing between the bars other than those near the center. However, as in the fourth embodiment, the spacing between the bars near the bottom in the arrangement direction may be made wider than the spacing between the bars other than those near the bottom.

[0155] In the above embodiments, the arrangement direction of the bar sections was set to the vertical direction (Z direction) of the battery cell 20. However, the arrangement direction of the bar sections may also be the width direction (Y direction) of the battery cell 20. Also, the number of bar sections can be changed as appropriate.

[0156] The application of each of the above embodiments is not particularly limited in terms of the type of battery, such as nickel-metal hydride secondary batteries or lithium-ion secondary batteries. [Explanation of symbols]

[0157] 10…Battery module 11…Lower case 11A...Floor section 11B... End wall section 13…Spacer 13A…Space forming part 13B…Space forming part 13C…Space forming part 14… End plate 15…Space 20…Battery cells 20A…First battery cell 20B…Second battery cell 21...face 30... Bar section 31...First bar section 32...Second bar section 33... Third Bar Section 34...4th Bar Section 35...Fin section 36…First fin section 37...Second fin section 38…Third fin section 39…Fourth fin section 40... Bar section 41...First bar section 42...Second bar section 43... Third Bar Section 44... Section 4 45...Fin section 46A...First fin section 46B...First stopper section 47A...Second fin section 47B...Second stopper section 48…Third fin section 49…Fourth fin section 50... Bar section 51...First bar section 52...Second bar section 53... Third Bar Section 54...4th Bar Section 55...Fin section 56…First fin section 57...Second fin section 58…Third fin section 59…Fourth fin section LA…1st fin length LB...Second fin length LC…3rd fin length LD...4th fin length LE…5th fin length LF...6th fin length P1,P2,P3,P4,P5,P6…interval

Claims

1. A battery module in which multiple battery cells and synthetic resin spacers placed between the battery cells are alternately stacked, The previous spacer is Multiple bar sections are arranged at intervals from each other along the aforementioned battery cell, A first fin portion is provided on the bar portion, is inclined with respect to the arrangement direction in which the bar portion is arranged and extends toward one of the battery cells, and is formed such that its longitudinal end, which is perpendicular to the arrangement direction and parallel to the surface of the battery cell, is not connected, and is in contact with the surface of the one battery cell. The bar portion is provided with a second fin portion that is inclined with respect to the arrangement direction and extends to the other battery cell, which is different from the one battery cell, and is formed such that its longitudinal end, which is perpendicular to the arrangement direction and parallel to the surface of the battery cell, is not connected, and which is in contact with the surface of the other battery cell. The spacing between the bar sections closer to the center in the aforementioned arrangement direction is wider than the spacing between the bar sections other than those closer to the center. Battery module.

2. A battery module in which multiple battery cells and synthetic resin spacers placed between the battery cells are alternately stacked, The previous spacer is Multiple bar sections are arranged at intervals from each other along the aforementioned battery cell, A first fin portion is provided on the bar portion, is formed inclined with respect to the arrangement direction in which the bar portions are arranged, and extends toward one of the battery cells, and is in contact with the surface of the one battery cell, The bar portion is provided with a second fin portion which is formed inclined with respect to the arrangement direction and extends toward the other battery cell, which is different from the one battery cell, and which is in contact with the surface of the other battery cell, The spacing between the plurality of bar sections near the center in the aforementioned arrangement direction is wider than the spacing between the plurality of bar sections other than those near the center. Each of the first fin portion and the second fin portion has a length corresponding to the distance between the bar portions, The lengths of the first and second fin portions located near the center in the direction of arrangement are longer than the lengths of the first and second fin portions located at locations other than near the center in the direction of arrangement. Battery module.

3. A battery module in which multiple battery cells and synthetic resin spacers placed between the battery cells are alternately stacked, The previous spacer is Multiple bar sections are arranged at intervals from each other along the aforementioned battery cell, A first fin portion is provided on the bar portion, is formed inclined with respect to the arrangement direction in which the bar portions are arranged, and extends toward one of the battery cells, and is in contact with the surface of the one battery cell, The bar portion is provided with a second fin portion which is formed inclined with respect to the arrangement direction and extends toward the other battery cell, which is different from the one battery cell, and which is in contact with the surface of the other battery cell, The spacing between the multiple bar sections near the bottom in the aforementioned arrangement direction is wider than the spacing between the multiple bar sections other than those near the bottom. Battery module.

4. Each of the first fin portion and the second fin portion has a length corresponding to the distance between the bar portions, The lengths of the first and second fin portions located near the bottom surface in the aforementioned arrangement direction are longer than the lengths of the first and second fin portions located at other points in the arrangement direction. The battery module according to claim 3.

5. The first fin portion and the second fin portion are provided on the same bar portion among the plurality of bar portions. A battery module according to any one of claims 1 to 4.

6. The first fin portion is inclined with respect to the first arrangement direction in the arrangement direction, The second fin portion is inclined with respect to a second arrangement direction opposite to the first arrangement direction. The battery module according to claim 5.

7. The first fin portion is provided on the first bar portion among the plurality of bar portions, The second fin portion is provided on a second bar portion that is different from the first bar portion among the plurality of bar portions. A battery module according to any one of claims 1 to 4.

8. The first fin section comprises two of the above-mentioned fin sections, One of the first fin portions is inclined with respect to the first arrangement direction in the arrangement direction, The other side of the first fin portion is inclined with respect to a second arrangement direction opposite to the first arrangement direction, The second fin section comprises two of the above-mentioned fin sections, One of the second fin portions is inclined with respect to the first arrangement direction, The other side of the second fin portion is inclined with respect to the second arrangement direction. The battery module according to claim 7.

9. The first fin portion is inclined with respect to the first arrangement direction in the arrangement direction, The second fin portion is inclined with respect to the first arrangement direction, The first bar portion is formed to extend in a second arrangement direction opposite to the first arrangement direction, The second bar portion comprises a second stopper portion formed extending in the second arrangement direction. The battery module according to claim 7.

10. A spacer made of synthetic resin, which is placed between multiple battery cells that make up a battery module, Multiple bar sections arranged with space between them, A first fin portion is provided on the first bar portion included in the bar portion, extending inclined with respect to the first arrangement direction in the arrangement direction in which the bar portions are arranged, and extending in a first orthogonal direction perpendicular to the arrangement direction, and formed such that its longitudinal end, which is perpendicular to the arrangement direction and parallel to the surface of the battery cell, is not connected. The first bar portion is provided with a second fin portion that extends inclined with respect to a second arrangement direction opposite to the first arrangement direction and in the first orthogonal direction, and is formed such that its longitudinal end, which is perpendicular to the arrangement direction and parallel to the surface of the battery cell, is not connected, The spacing between the bar sections closer to the center in the aforementioned arrangement direction is wider than the spacing between the bar sections other than those closer to the center. Spacer.

11. A spacer made of synthetic resin, which is placed between multiple battery cells that make up a battery module, Multiple bar sections arranged with space between them, A first fin portion is provided on the first bar portion included in the bar portion, and is formed to extend in a first orthogonal direction that is perpendicular to the arrangement direction and inclined with respect to the first arrangement direction in which the bar portions are arranged, The first bar portion is provided with a second fin portion that is inclined with respect to a second arrangement direction opposite to the first arrangement direction and extends in a first orthogonal direction, The spacing between the plurality of bar sections near the center in the aforementioned arrangement direction is wider than the spacing between the plurality of bar sections other than those near the center. Each of the first fin portion and the second fin portion has a length corresponding to the distance between the bar portions, The lengths of the first and second fin portions located near the center in the direction of arrangement are longer than the lengths of the first and second fin portions located at locations other than near the center in the direction of arrangement. Spacer.

12. A spacer made of synthetic resin, which is placed between multiple battery cells that make up a battery module, Multiple bar sections arranged with space between them, A first fin portion is provided on the first bar portion included in the bar portion, extending inclined with respect to the first arrangement direction in the arrangement direction in which the bar portions are arranged, and extending in a first orthogonal direction perpendicular to the arrangement direction, and formed such that its longitudinal end, which is perpendicular to the arrangement direction and parallel to the surface of the battery cell, is not connected. The first bar portion is provided with a second fin portion that extends inclined with respect to a second arrangement direction opposite to the first arrangement direction and in the first orthogonal direction, and is formed such that its longitudinal end, which is perpendicular to the arrangement direction and parallel to the surface of the battery cell, is not connected, The spacing between the multiple bar sections near the bottom in the aforementioned arrangement direction is wider than the spacing between the multiple bar sections other than those near the bottom. Spacer.

13. A spacer made of synthetic resin, which is placed between multiple battery cells that make up a battery module, Multiple bar sections arranged with space between them, A first fin portion is provided on the first bar portion included in the bar portion, and is formed to extend in a first orthogonal direction that is perpendicular to the arrangement direction and inclined with respect to the first arrangement direction in which the bar portions are arranged, The first bar portion is provided with a second fin portion that is inclined with respect to a second arrangement direction opposite to the first arrangement direction and extends in a first orthogonal direction, The spacing between the plurality of bar portions near the bottom in the aforementioned arrangement direction is wider than the spacing between the plurality of bar portions other than those near the bottom. Each of the first fin portion and the second fin portion has a length corresponding to the distance between the bar portions, The lengths of the first and second fin portions located near the bottom surface in the aforementioned arrangement direction are longer than the lengths of the first and second fin portions located at other points in the arrangement direction. Spacer.

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