Battery module and spacer

Abstract

To provide a battery module and a spacer, capable of cooling battery cells adequately.SOLUTION: Provided is a battery module in which a plurality of battery cells 20 and a synthetic resin spacer 13 disposed between the battery cells 20 are alternately stacked. The spacer 13 includes: a plurality of bar parts 50 extending in a longitudinal direction along the battery cells 20 and arranged to be spaced apart from each other in an arrangement direction crossing the longitudinal direction; a first fin part 56 extending from the bar parts 50 toward a first battery cell 20A and being in contact with the surface of the first battery cell 20A, the first fin part having a predetermined thickness; and a second fin part 57 extending from the bar parts 50 toward a second battery cell 20B and being in contact with the surface of the second battery cell 20B, the second fin part having a predetermined thickness. At the fin part 55, the thickness of each of both ends in the longitudinal direction is thicker than the thickness of a center in the longitudinal direction.SELECTED DRAWING: Figure 6

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, the internal pressure of the battery cells in the battery module 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 spacer has a plurality of bar portions extending in the longitudinal direction along the battery cell and arranged at intervals from each other in an arrangement direction intersecting the longitudinal direction, a first fin portion extending from the bar portions toward one of the battery cells with a predetermined thickness and in contact with the surface of the one battery cell, and a second fin portion extending from the bar portions toward the other battery cell different from the one battery cell with a predetermined thickness and in contact with the surface of the other battery cell, wherein the first fin portion and the second fin portion are separate fin portions, and in each fin portion, the thickness of both ends in the longitudinal direction is greater than the thickness of the central part in the longitudinal direction.

[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 thickness of both ends of each fin portion in the longitudinal direction of the bar portion is greater than the thickness of the central portion. As a result, when the battery cells are pressed by the fin portion of the spacer placed between them, the pressure on the central portion of the battery cell by the fin portion is lower than the pressure on the ends of the battery cell. This makes it possible to suppress the pressure on the central portion when the battery cell expands due to charging and discharging.

[0007] 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 spacer has a plurality of bar portions extending in the longitudinal direction along the battery cell and arranged at intervals from each other in an arrangement direction intersecting the longitudinal direction, a first fin portion extending from the bar portion toward one of the battery cells having a predetermined thickness and in contact with the surface of the one battery cell, and a second fin portion extending from the bar portion toward the other battery cell different from the one battery cell having a predetermined thickness and in contact with the surface of the other battery cell, wherein the direction perpendicular to the longitudinal direction and the arrangement direction is the thickness direction of the bar portion, the first fin portion and the second fin portion are separate fin portions, in the bar portion the thickness at both ends in the longitudinal direction is thicker than the thickness at the center in the longitudinal direction, and in each fin portion the thickness at the center in the longitudinal direction is thicker than the thickness at both ends in the longitudinal direction.

[0008] 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 thickness of both ends of the bar portion is greater than the thickness of the center portion, and the thickness of the center portion of the fin portion in the longitudinal direction of the bar portion is greater than the thickness of both ends. As a result, when the battery cells are pressed by the spacer placed between them, the pressure on the center portion of the battery cell by the bar portion is lower than the pressure on the ends of the battery cell, and the center portion of the battery cell is pressed more by the fin portion than by the ends. This suppresses the pressure on the center portion by the bar portion when the battery cell expands due to charging and discharging, while the deformation of the case can be suppressed by the fin portion pressing on the center portion with a surface.

[0009] 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.

[0010] 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.

[0011] 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.

[0012] 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.

[0013] 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 fin provided on the first bar portion and the second fin portion provided on the second bar portion separately contacting both adjacent battery cells.

[0014] Preferably, the above-described battery module comprises 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 comprises 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.

[0015] 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.

[0016] Preferably, the battery module described above includes a first fin portion that is inclined with respect to a first array direction, a second fin portion that is inclined with respect to a first array direction, a first stopper portion formed on the first bar portion that extends in a second array direction opposite to the first array direction, and a second stopper portion formed on the second bar portion that extends in the second array direction.

[0017] 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.

[0018] A spacer that solves the above problem is a synthetic resin spacer that is placed between a plurality of battery cells constituting a battery module, and is arranged with a gap between them, and has a plurality of bar portions that extend in a longitudinal direction perpendicular to the arrangement direction, a first fin portion that is provided from the bar portions with a predetermined thickness and is formed to extend in a first orthogonal direction that is inclined with respect to a first arrangement direction in the arrangement direction and perpendicular to the arrangement direction, and a second fin portion that is provided from the bar portions with a predetermined thickness and is formed to extend in the first orthogonal direction that is inclined with respect to a second arrangement direction opposite to the first arrangement direction, wherein the first fin portion and the second fin portion are separate fin portions, and in each fin portion, the thickness of both ends in the longitudinal direction is greater than the thickness of the central part in the longitudinal direction.

[0019] 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 thickness of both ends of the fin portion in the longitudinal direction of the bar portion is greater than the thickness of the center portion. As a result, when the battery cells are pressed by the fin portion of the spacer placed between them, the pressure on the center portion of the battery cell by the fin portion is lower than the pressure on the ends portion of the battery cell. This makes it possible to suppress the pressure on the center portion when the battery cell expands due to charging and discharging.

[0020] A spacer that solves the above problem is a spacer made of synthetic resin that is placed between a plurality of battery cells constituting a battery module, and is arranged with a gap between them and has a plurality of bar portions that extend in a longitudinal direction perpendicular to the arrangement direction, a first fin portion that is provided from the bar portions with a predetermined thickness and is formed to extend in a first orthogonal direction that is inclined with respect to a first arrangement direction in the arrangement direction and perpendicular to the arrangement direction, and a second fin portion that is provided from the bar portions with a predetermined thickness and is formed to extend in the first orthogonal direction that is inclined with respect to a second arrangement direction opposite to the first arrangement direction, wherein the longitudinal direction and the direction perpendicular to the arrangement direction are the thickness directions of the bar portions, the first fin portion and the second fin portion are separate fin portions, in the bar portions the thickness of both ends in the longitudinal direction is greater than the thickness of the central part in the longitudinal direction, and in each fin portion the thickness of the central part in the longitudinal direction is greater than the thickness of both ends in the longitudinal direction.

[0021] 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. Thus, heat dissipation to the space between the battery cells is appropriately performed, and the battery cells can be appropriately cooled. Further, the thickness of the bar portion is greater at both ends than at the central portion, and the thickness of the central portion of the fin portion in the longitudinal direction of the bar portion is greater than the thicknesses of both ends. For this reason, when the battery cells are pressed by the spacer disposed between the battery cells, the pressing of the central portion of the battery cell by the bar portion becomes lower than the pressing of the end portions of the battery cell, and the central portion of the battery cell is pressed by the surface by the first fin portion and the second fin portion more than the end portions. Thereby, when the battery cells expand due to charge and discharge, it is possible to suppress deformation of the case by pressing the central portion with the surface by the fin portion while suppressing the pressing on the central portion by the bar portion.

Advantages of the Invention

[0022] According to the present invention, the battery cells can be appropriately cooled.

Brief Description of the Drawings

[0023] [Figure 1] It is a perspective view showing a schematic configuration of a battery module according to the first embodiment. [Figure 2] It is a cross-sectional view taken along line 2-2 of FIG. 1 of the battery module according to the same embodiment. [Figure 3] It is a perspective view of the spacer according to the same embodiment. [Figure 4] It is a front view of the spacer according to the same embodiment. [Figure 5] It is a cross-sectional view taken along line 5-5 of FIG. 4 of the space forming portion of the spacer in the non-compressed state according to the same embodiment. [Figure 6] It is a cross-sectional view taken along line 6-6 of FIG. 4 of the space forming portion of the spacer in the non-compressed state according to the same 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, shown at line 5-5 in Figure 4. [Figure 8] This is a cross-sectional view of the space-forming portion of the spacer in the compressed state of the same embodiment, shown at 6-6 in Figure 4. [Figure 9] This is a perspective view of the spacer according to the second embodiment. [Figure 10] This is a front view of the spacer according to the same embodiment. [Figure 11] This is a cross-sectional view of the space-forming portion of the spacer in the uncompressed state of the same embodiment, shown at line 11-11 in Figure 10. [Figure 12] This is a cross-sectional view of the space-forming portion of the spacer in the uncompressed state of the same embodiment, shown at line 12-12 in Figure 10. [Figure 13] This is a cross-sectional view of the space-forming portion of the spacer in the compressed state of the same embodiment, shown at line 11-11 in Figure 10. [Figure 14] This is a cross-sectional view of the space-forming portion of the spacer in the compressed state of the same embodiment, shown at line 12-12 in Figure 10. [Figure 15] This is a cross-sectional view of the space-forming portion of the spacer in the uncompressed state of the third embodiment. [Figure 16] This is a cross-sectional view of the space-forming portion of the spacer in the compressed state of the same embodiment. [Figure 17] This is a cross-sectional view of the space-forming portion of the spacer in the uncompressed state of the fourth embodiment. [Figure 18] 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]

[0024] (First Embodiment) The first embodiment of the battery module and spacer will be described below with reference to Figures 1 to 8.

[0025] (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.

[0026] 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.

[0027] 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.

[0028] (Spacer 13) As shown in Figures 3 and 4, 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.

[0029] 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 at intervals from each other in the vertical direction (Z direction) along the surface 21 of the battery cell 20. The longitudinal direction and the arrangement direction intersect. 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.

[0030] (Space forming part 13C) Next, the space-forming portion 13C will be described in detail with reference to Figures 5 to 8. Figures 5 to 8 are cross-sectional views of the space-forming portion 13C of the spacer 13. Figure 5 shows a 5-5 cross-section including the end of the uncompressed space-forming portion 13C, together with the adjacent battery cells 20. Figure 6 shows a 6-6 cross-section including the end of the uncompressed space-forming portion 13C, together with the adjacent battery cells 20. Figure 7 shows a 5-5 cross-section including the central part of the compressed space-forming portion 13C, together with the adjacent battery cells 20. Figure 8 shows a 6-6 cross-section including the central part of the compressed space-forming portion 13C, together with the adjacent battery cells 20.

[0031] As shown in Figures 5 to 8, 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 cross-sectional shape of the bar section 50 is rectangular. The fin section 55 has a first fin section 56 and a second fin section 57. The thickness of both ends of the fin section 55 (Figures 5 and 7) is greater than the thickness of the central part (Figures 6 and 8) in the longitudinal direction (Y direction) of the bar section 50. The direction perpendicular to the longitudinal direction and the arrangement direction is the thickness direction of the bar section 50. The thickness of the bar section 50 is the same in the longitudinal direction of the bar section 50, both in the central part (Figures 6 and 8) and at both ends (Figures 5 and 7).

[0032] As shown in Figures 5 and 6, the first bar portion 51 and the second bar portion 52 are 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) 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 second fin portion 57 is formed extending in a second orthogonal direction (to the left in the figure) opposite to the first orthogonal direction, at a second angle θB 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 the same angle.

[0033] The third bar portion 53 is provided with a second fin portion 57. The second fin portion 57 is formed extending in a second orthogonal direction (left direction in the figure) at a second angle θB inclined with respect to the second alignment direction (downward direction). The second fin portion 57 is in contact with the left side surface 21 of the second battery cell 20B.

[0034] 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 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.

[0035] (Uncompressed state) As shown in FIGS. 5 and 6, in the uncompressed 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 of the first bar portion 51. In the uncompressed 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 of the first bar portion 51. In the uncompressed state, the tip of the first fin portion 56 provided on the second bar portion 52 protrudes toward the first battery cell 20A side on the right side of the second bar portion 52. In the uncompressed state, the tip of the second fin portion 57 provided on the second bar portion 52 protrudes toward the second battery cell 20B side on the left side of the second bar portion 52. The tip of the second fin portion 57 provided on the third bar portion 53 protrudes toward the second battery cell 20B side on the left side of 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 of 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.

[0036] The first fin length LA, which is the length of the first fin portion 56 from the first bar portion 51, and the second fin length LB, which is the length of the second fin portion 57 from the third bar portion 53, are both shorter than the distance P between the first bar portion 51 and the third bar portion 53 (LA < P, LB < P). The first fin length LA and the second fin length LB are the same length (LA = LB). The sum of the first fin length LA and the second fin length LB is longer than the distance P between the first bar portion 51 and the third bar portion 53 (LA + LB > P).

[0037] The second fin length LB, which is the length of the second fin portion 57 from the first bar portion 51, and the first fin length LA, which is the length of the first fin portion 56 from the second bar portion 52, are both shorter than the distance P between the first bar portion 51 and the second bar portion 52 (LB < P, LA < P). The second fin length LB and the first fin length LA are the same length (LB = LA). The sum of the second fin length LB and the first fin length LA is longer than the distance P between the first bar portion 51 and the second bar portion 52 (LB + LA > P).

[0038] The second fin length LB, which is the length of the second fin portion 57 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 P between the second bar portion 52 and the fourth bar portion 54 (LB < P, LA < P). The second fin length LB and the first fin length LA are of the same length (LB = LA). The sum of the second fin length LB and the first fin length LA is longer than the interval P between the second bar portion 52 and the fourth bar portion 54 (LB + LA > P).

[0039] The sum of the projection lengths LZA in the arrangement direction (Z direction) of the first fin portion 56 and the projection length LZB in the arrangement direction (Z direction) of the second fin portion 57 is shorter than the interval P between the first bar portion 51 and the third bar portion 53 in the non-compressed state (LZA + LZB < P). For this reason, in the non-compressed state, a gap G is provided in the arrangement direction (Z direction) between the tips of the first fin portion 56 and the second fin portion 57. Thereby, the first fin portion 56 and the second fin portion 57 are prevented from overlapping in the arrangement direction (Z direction). Such a spacer 13 can be manufactured at a low cost.

[0040] The sum of the projection length LZB in the arrangement direction (Z direction) of the second fin portion 57 and the projection length LZA in the arrangement direction (Z direction) of the first fin portion 56 is shorter than the interval P between the first bar portion 51 and the second bar portion 52 in the non-compressed state (LZB + LZA < P). For this reason, in the non-compressed state, a gap G is provided in the arrangement direction (Z direction) between the tips of the second fin portion 57 and the first fin portion 56. Thereby, the second fin portion 57 and the first fin portion 56 are prevented from overlapping in the arrangement direction (Z direction). Such a spacer 13 can be manufactured at a low cost.

[0041] The sum of the projection length LZB in the arrangement direction (Z direction) of the second fin portion 57 and the projection length LZA in the arrangement direction (Z direction) of the first fin portion 56 is shorter than the distance P between the second bar portion 52 and the fourth bar portion 54 in the non-compressed state (LZB + LZA < P). Therefore, in the non-compressed state, a gap G is provided in the arrangement direction (Z direction) between the tips of the second fin portion 57 and the first fin portion 56. As a result, the second fin portion 57 and the first fin portion 56 do not overlap in the arrangement direction (Z direction). Such a spacer 13 can be manufactured at a low cost.

[0042] (Compressed state) As shown in FIGS. 7 and 8, 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 is suppressed by the bar portion 50. And a space 15 is formed between the two bar portions 50 adjacent to each other 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.

[0043] Since the surface 21 of the right first battery cell 20A is in contact with the right side surface of the first bar portion 51, the first fin portion 56 provided on the first bar portion 51 is pressed to the left by the surface 21 of the right first battery cell 20A. By this pressing, the first fin portion 56 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 56 extends upward along the surface 21 of the right first battery cell 20A. And the bent first fin portion 56 presses the surface 21 of the right first battery cell 20A to the right by the reaction force of the bending.

[0044] 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.

[0045] 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 first fin portion 56 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 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. Then, due to the reaction force of its bending, the bent first fin portion 56 presses the surface 21 of the right first battery cell 20A to the right.

[0046] The left side of the second bar portion 52 is in contact with the left side surface 21 of the second battery cell 20B, causing the second fin portion 57 provided on the second bar portion 52 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.

[0047] 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 second fin portion 57 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 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.

[0048] 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.

[0049] As mentioned above, the first fin length LA of the first fin portion 56 and the second fin length LB of the second fin portion 57 are both shorter than the distance P 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 on the surface 21 that is not covered by the first fin portion 56 at the distance P 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 on the surface 21 that is not covered by the second fin portion 57 at the distance P between the first bar portion 51 and the third bar portion 53.

[0050] Similarly, the second fin length LB of the second fin portion 57 and the first fin length LA of the first fin portion 56 are both shorter than the distance P between the first bar portion 51 and the second bar portion 52. 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 57 at the distance P between the first bar portion 51 and the second bar portion 52. 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 second fin portion 57 at the distance P between the first bar portion 51 and the second bar portion 52.

[0051] Similarly, the second fin length LB of the second fin portion 57 and the first fin length LA of the first fin portion 56 are both shorter than the distance P 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 surface 21 that is not covered by the second fin portion 57 at the distance P between the second bar portion 52 and the fourth bar portion 54. 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 56 at the distance P between the second bar portion 52 and the fourth bar portion 54.

[0052] 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.

[0053] Furthermore, as mentioned above, the sum of the first fin length LA of the first fin portion 56 and the second fin length LB of the second fin portion 57 is longer than the distance P between the first bar portion 51 and the third bar portion 53. Therefore, in the compressed state, the first fin portion 56 and the second fin portion 57 overlap in the alignment direction (Z direction). In other words, there is an overlap L between the tip of the first fin portion 56 and the tip of the second fin portion 57. Thus, the first fin portion 56 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 second fin portion 57. The second fin portion 57 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 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 P 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 second fin portion 57. 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 second fin portion 57 respectively, at least one of the first fin portion 56 and the second fin portion 57 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.

[0054] Similarly, the sum of the second fin length LB of the second fin portion 57 and the first fin length LA of the first fin portion 56 is longer than the distance P between the first bar portion 51 and the second bar portion 52. Therefore, in the compressed state, the second fin portion 57 and the first fin portion 56 overlap in the alignment direction (Z direction). In other words, there is an overlap L between the tip of the second fin portion 57 and the tip of the first fin portion 56. Thus, the second fin portion 57 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 first fin portion 56. The first fin portion 56 presses on 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 portion 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 P 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 first fin portion 56. 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.

[0055] Similarly, the sum of the second fin length LB of the second fin portion 57 and the first fin length LA of the first fin portion 56 is longer than the distance P between the second bar portion 52 and the fourth bar portion 54. Therefore, in the compressed state, the second fin portion 57 and the first fin portion 56 overlap in the alignment direction (Z direction). In other words, there is an overlap L between the tip of the second fin portion 57 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 second fin portion 57. The second fin portion 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 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 P 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 second fin portion 57. 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 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.

[0056] As shown in Figures 7 and 8, the thickness of the first fin portion 56 and the second fin portion 57 is greater at both ends than in the center. The greater the thickness of the fin portion 55, the less it bends, and therefore the greater the thickness, the higher the pressure. That is, when the spacer 13 placed between the battery cells 20 is pressed against the battery cells 20, the pressure on the center of the battery cell 20 by the first fin portion 56 and the second fin portion 57 becomes lower than the pressure on the ends of the battery cell 20. 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.

[0057] 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. Therefore, the spacer 13 can prevent the flow rate of the cooling gas flowing into 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 into the space 15. Furthermore, even if the battery cell 20 expands due to some factor, the third bar portion 53 and the fourth bar portion 54 can push the case 22 of the battery cell 20 in, and the electrode body 23 can be held in place.

[0058] 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 thickness of the fin portion 55 in the longitudinal direction of the bar portion 50 is thicker at both ends than at the center. As a result, when the battery cells 20 are pressed by the fin portion 55 of the spacer 13 placed between the battery cells 20, the pressure on the center of the battery cell 20 by the fin portion 55 is lower than the pressure on the ends of the battery cell 20. This makes it possible to suppress the pressure on the center when the battery cell 20 expands due to charging and discharging.

[0059] (1-2) 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.

[0060] (1-3) 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. Therefore, 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.

[0061] (Second Embodiment) The second embodiment of the battery module and spacer will be described below with reference to Figures 9 to 14. The battery module and spacer of the second embodiment differ from those of the first embodiment in the space-forming portion. The differences from the first embodiment will be described below.

[0062] (Spacer 13) As shown in Figures 9 and 10, the spacer 13 has a space-forming portion 13D. The space-forming portion 13D is located in the central part of the spacer 13. The space-forming portion 13D is the part that forms a space between the battery cells 20 located on either side of the spacer 13.

[0063] (Space forming part 13D) Next, the space-forming portion 13D will be described in detail with reference to Figures 11 to 14. Figures 11 to 14 are cross-sectional views of the space-forming portion 13D of the spacer 13. Figure 11 shows the 11-11 cross-section including the end of the uncompressed space-forming portion 13D, together with the adjacent battery cells 20. Figure 12 shows the 12-12 cross-section including the end of the uncompressed space-forming portion 13D, together with the adjacent battery cells 20. Figure 13 shows the 11-11 cross-section including the central part of the compressed space-forming portion 13D, together with the adjacent battery cells 20. Figure 14 shows the 12-12 cross-section including the central part of the compressed space-forming portion 13C, together with the adjacent battery cells 20.

[0064] As shown in Figures 11 to 14, similar to the first embodiment, the bar portion 50 has, from top to bottom, a third bar portion 53, a first bar portion 51, a second bar portion 52, and a fourth bar portion 54. The fin portion 55 has a first fin portion 56 and a second fin portion 57. The direction perpendicular to the longitudinal direction and the arrangement direction is the thickness direction of the bar portion 50. The thickness of both ends of the bar portion 50 (Figures 11, 13) is greater than the thickness of the central portion (Figures 12, 14). The thickness of the central portion (Figures 12, 14) of the fin portion 55 in the longitudinal direction (Y direction) of the bar portion 50 is greater than the thickness of both ends (Figures 11, 13).

[0065] As shown in Figures 13 and 14, the thickness of both ends of the bar portion 50 is greater than the thickness of the central portion. When compressed, the bar portion 50 is pressed against the surface of the battery cell 20. That is, when the spacers 13 placed between the battery cells 20 are pressed against the battery cells 20, the pressure on the central portion of the battery cell 20 by the bar portion 50 becomes lower than the pressure on the ends of the battery cell 20. This lower pressure on the central portion of the battery cell 20 may lead to greater expansion of the central portion of the case 22. However, the thickness of the fin portion 55 is greater in the center than at both ends. That is, when the spacers 13 placed between the battery cells 20 are pressed against the battery cells 20, the pressure on the central portion of the battery cell 20 by the fin portion 55 becomes higher than the pressure on the ends of the battery cell 20. Therefore, when the battery cell 20 expands due to charging and discharging, the pressure on the central portion by the bar portion 50 is suppressed, while the central portion is pressed across by the fin portion 55, thereby suppressing deformation of the case 22. 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 compressed 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. Therefore, the spacer 13 can prevent the flow rate of the cooling gas flowing into 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 into the space 15. Furthermore, even if the battery cell 20 expands due to some factor, the third bar portion 53 and the fourth bar portion 54 can push the case 22 of the battery cell 20 in, and the electrode body 23 can be held in place.

[0067] Next, the effects of the second embodiment will be described. In addition to the effects of (1-2) and (1-3) of the first embodiment, the following effects are also achieved. (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 thickness of the bar portion 50 is greater at both ends than in the center, and the thickness of the fin portion 55 in the longitudinal direction of the bar portion 50 is greater in the center than at both ends. Therefore, when the battery cells 20 are pressed by the spacers 13 placed between them, the pressure on the center of the battery cell 20 by the bar portion 50 is lower than that on the edges of the battery cell 20, and the center of the battery cell 20 is pressed more evenly by the fin portion 55 than on the edges. As a result, when the battery cell 20 expands due to charging and discharging, the pressure on the center by the bar portion 50 is suppressed, while the deformation of the case 22 is suppressed by the fin portion 55 pressing the center evenly.

[0068] (Third embodiment) A third embodiment of the battery module and spacer will be described below with reference to Figures 15 and 16. The shape of the fin portion in the first and second embodiments may be changed as in the third embodiment. The differences from the first and second embodiments will be described below.

[0069] (Space forming part 13A) Next, the space-forming portion 13A will be described in detail with reference to Figures 15 and 16. Figures 15 and 16 are cross-sectional views of the space-forming portion 13A of the spacer 13. Figure 15 shows the space-forming portion 13A in an uncompressed state together with the adjacent battery cells 20. Figure 16 shows the space-forming portion 13A in a compressed state together with the adjacent battery cells 20.

[0070] As shown in Figure 15, 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 cross-sectional shape of the bar section 30 is rectangular. 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.

[0071] 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 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 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 right-side first battery cell 20A. The first angle θA and the second angle θB are the same angle.

[0072] 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 at a third angle θC with respect to the first alignment direction (upward direction) and extends in a second orthogonal direction (leftward direction in the figure), opposite to the first orthogonal direction (rightward direction in the figure). The fourth fin portion 39 is formed at a fourth angle θD with respect to the second alignment direction (downward direction) and extends in a second orthogonal direction (leftward direction in the figure). The third fin portion 38 and the fourth fin portion 39 are in contact with the left side surface 21 of the second battery cell 20B. The third angle θC and the fourth angle θD are the same angle. The first angle θA and the third angle θC are the same angle.

[0073] The third bar portion 33 is provided with a fourth fin portion 39. 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 second alignment direction (downward direction). The fourth fin portion 39 is in contact with the left side surface 21 of the second battery cell 20B.

[0074] The fourth bar portion 34 is provided with a first fin portion 36. The first fin portion 36 is formed to extend in a first orthogonal direction (rightward in the drawing) while being inclined at a first angle θA with respect to a first arrangement direction (upward direction). The first fin portion 36 is in contact with the surface 21 of the right first battery cell 20A.

[0075] (Non-compressed state) As shown in FIG. 15, in the non-compressed 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 of the first bar portion 31. Also, in the non-compressed 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 of 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 of 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 of 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 are not in contact with the surface 21 of the right first battery cell 20A nor with the surface 21 of the left second battery cell 20B.

[0076] A first fin length LA, which is the length of the first fin portion 36 from the first bar portion 31, and a fourth fin length LD, which is the length of the fourth fin portion 39 from the third bar portion 33, are both shorter than the distance P between the first bar portion 31 and the third bar portion 33 (LA < P, LD < P). The first fin length LA and the fourth fin length LD are of the same length (LA = LD). The sum of the first fin length LA and the fourth fin length LD is longer than the distance P between the first bar portion 31 and the third bar portion 33 (LA + LD > P).

[0077] The second fin length LB, which is the length of the second fin portion 37 from the first bar portion 31, and the third fin length LC, which is the length of the third fin portion 38 from the second bar portion 32, are both shorter than the interval P between the first bar portion 31 and the second bar portion 32 (LB < P, LC < P). The second fin length LB and the third fin length LC are of the same length (LB = LC). The sum of the second fin length LB and the third fin length LC is longer than the interval P between the first bar portion 31 and the second bar portion 32 (LB + LC > P).

[0078] The fourth fin length LD, which is the length of the fourth fin portion 39 from the second bar portion 32, and the first fin length LA, which is the length of the first fin portion 36 from the fourth bar portion 34, are both shorter than the interval P between the second bar portion 32 and the fourth bar portion 34 (LD < P, LA < P). The fourth fin length LD and the first fin length LA are of the same length (LD = LA). The sum of the fourth fin length LD and the first fin length LA is longer than the interval P between the second bar portion 32 and the fourth bar portion 34 (LD + LA > P).

[0079] The sum of the projection lengths LZA and LZD in the arrangement direction (Z direction) of the first fin portion 36 and the fourth fin portion 39 is shorter than the interval P between the first bar portion 31 and the third bar portion 33 in the non-compressed state (LZA + LZD < P). For this reason, in the non-compressed state, a gap G is provided in the arrangement direction (Z direction) between the tips of the first fin portion 36 and the fourth fin portion 39. As a result, the first fin portion 36 and the fourth fin portion 39 do not overlap in the arrangement direction (Z direction). Such a spacer 13 can be manufactured at a low cost.

[0080] The sum of the projection length LZB in the arrangement direction (Z direction) of the second fin portion 37 and the projection length LZC in the arrangement direction (Z direction) of the third fin portion 38 is shorter than the distance P between the first bar portion 31 and the second bar portion 32 in the non-compressed state (LZB + LZC < P). Therefore, in the non-compressed state, a gap G is provided in the arrangement direction (Z direction) between the tips of the second fin portion 37 and the third fin portion 38. As a result, the second fin portion 37 and the third fin portion 38 do not overlap in the arrangement direction (Z direction). Such a spacer 13 can be manufactured at a low cost.

[0081] The sum of the projection length LZD in the arrangement direction (Z direction) of the fourth fin portion 39 and the projection length LZA in the arrangement direction (Z direction) of the first fin portion 36 is shorter than the distance P between the second bar portion 32 and the fourth bar portion 34 in the non-compressed state (LZD + LZA < P). Therefore, in the non-compressed state, a gap G is provided in the arrangement direction (Z direction) between the tips of the fourth fin portion 39 and the first fin portion 36. As a result, the fourth fin portion 39 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.

[0082] (Compressed state) As shown in FIG. 16, 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 on both sides is suppressed by the bar portion 30. And a space 15 is formed between the two bar portions 30 adjacent to each other vertically, where the surfaces 21 of the battery cells 20 adjacent to both sides of the spacer 13 are separated.

[0083] The right side of the first bar portion 31 is in contact with the surface 21 of the right first battery cell 20A, causing the first fin portion 36 provided on the first bar portion 31 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.

[0084] 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.

[0085] 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 upward 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.

[0086] 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 downward along the left side surface 21 of the second battery cell 20B. Then, due to the reaction force of its bending, the bent fourth fin portion 39 presses the left side surface 21 of the second battery cell 20B to the left.

[0087] 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 fourth fin portion 39 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 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 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.

[0088] 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.

[0089] As mentioned above, the first fin length LA of the first fin portion 36 and the fourth fin length LD of the fourth fin portion 39 are both shorter than the distance P 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 P between the first bar portion 31 and the third bar portion 33. Similarly, on the left side of the second battery cell 20B, there is a portion on the surface 21 that is not covered by the fourth fin portion 39 at the distance P between the first bar portion 31 and the third bar portion 33.

[0090] Similarly, the second fin length LB of the second fin portion 37 and the third fin length LC of the third fin portion 38 are both shorter than the distance P 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 P 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 third fin portion 38 at the distance P between the first bar portion 31 and the second bar portion 32.

[0091] Similarly, the fourth fin length LD of the fourth fin portion 39 and the first fin length LA of the first fin portion 36 are both shorter than the distance P 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 fourth fin portion 39 at the distance P 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 P between the second bar portion 32 and the fourth bar portion 34.

[0092] Therefore, the surfaces 21 of the battery cells 20 adjacent to the spacer 13 are exposed to the space 15 at the distance P 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.

[0093] Furthermore, as mentioned above, the sum of the first fin length LA of the first fin portion 36 and the fourth fin length LD of the fourth fin portion 39 is longer than the distance P between the first bar portion 31 and the third bar portion 33. Therefore, in the compressed state, the first fin portion 36 and the fourth fin portion 39 overlap in the alignment direction (Z direction). In other words, there is an overlap L between the tip of the first fin portion 36 and the tip of the fourth fin portion 39. 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 fourth fin portion 39. The fourth fin portion 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 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 P between the bar portions 30, and are pressed away from each other by at least one of the first fin portion 36 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 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 fourth fin portion 39 respectively, at least one of the first fin portion 36 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.

[0094] Similarly, the sum of the second fin length LB of the second fin portion 37 and the third fin length LC of the third fin portion 38 is longer than the distance P between the first bar portion 31 and the second bar portion 32. Therefore, in the compressed state, the second fin portion 37 and the third fin portion 38 overlap in the alignment direction (Z direction). In other words, there is an overlap L between the tip of the second fin portion 37 and the tip of the third fin portion 38. Thus, the second fin portion 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 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 second fin portion 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 P between the bar portions 30, and are pressed away from each other by at least one of the second fin portion 37 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 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 third fin portion 38 respectively, at least one of the second fin portion 37 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.

[0095] Similarly, the sum of the fourth fin length LD of the fourth fin portion 39 and the first fin length LA of the first fin portion 36 is longer than the distance P between the second bar portion 32 and the fourth bar portion 34. Therefore, in the compressed state, the fourth fin portion 39 and the first fin portion 36 overlap in the alignment direction (Z direction). In other words, there is an overlap L between the tip of the fourth fin portion 39 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 fourth fin portion 39. The fourth fin portion 39 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 P between the bar portions 30, and are pressed away from each other by at least one of the first fin portion 36 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 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 fourth fin portion 39 and the first fin portion 36 respectively, at least one of the fourth fin portion 39 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.

[0096] The first fin portion 36 and the second fin portion 37 provided on the first bar portion 31 are pressed by the first battery cell 20A on the right side during compression. At this time, both the first fin portion 36 and the second fin portion 37 are pressed to the left. Therefore, if the first bar portion 31 is the center of rotation, the force exerted from the first fin portion 36 on the first bar portion 31 and the force exerted from the second fin portion 37 on the first bar portion 31 are in opposite directions and cancel each other out. Thus, there is no risk of the first bar portion 31 rotating.

[0097] Similarly, the third fin portion 38 and the fourth fin portion 39 provided on the second bar portion 32 are pressed from the second battery cell 20B on the left side during compression. At this time, both the third fin portion 38 and the fourth fin portion 39 are pressed to the right. Therefore, with the second bar portion 32 as the center of rotation, the force exerted from the third fin portion 38 on the second bar portion 32 and the force exerted from the fourth fin portion 39 on the second bar portion 32 are in opposite directions and cancel each other out. Thus, there is no risk of the second bar portion 32 rotating.

[0098] 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 into 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 into the space 15. Furthermore, even if the battery cell 20 expands due to some factor, the third bar portion 53 and the fourth bar portion 54 can push the case 22 of the battery cell 20 in, and the electrode body 23 can be held in place.

[0099] Next, the effects of the third embodiment will be described. In addition to the effects of (1-1) of the first embodiment or (2-1) of the second embodiment, the following effects are also achieved. (3-1) The first fin portion 36 and the second fin portion 37, which correspond to the first fin portion, are provided on the first bar portion 31, and the third fin portion 38 and the fourth fin portion 39, which correspond to the second fin portion, are provided on the second bar portion 32, which is different from the first bar portion 31. In this way, insulation can be ensured by the fin portion 35 provided on the first bar portion 31 and the fin portion 35 provided on the second bar portion 32 separately contacting both adjacent battery cells 20.

[0100] (3-2) 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 third fin portion 38 inclined with respect to the first arrangement direction and a fourth fin portion 39 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.

[0101] (Fourth Embodiment) A fourth embodiment of the battery module and spacer will be described below with reference to Figures 17 and 18. The shape of the fin portion in the first and second embodiments may be changed as in the fourth embodiment. The following description will focus on the differences from the first and second embodiments.

[0102] (Space forming part 13B) Figures 17 and 18 are cross-sectional views of the space-forming portion 13B of the spacer 13. Figure 17 shows the space-forming portion 13B in an uncompressed state together with the adjacent battery cells 20. Figure 18 shows the space-forming portion 13B in a compressed state together with the adjacent battery cells 20.

[0103] As shown in Figure 17, 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 cross-sectional shape of the bar section 40 is rectangular. 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.

[0104] 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 with respect to the first arrangement direction (downward direction) 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 direction) opposite to the first arrangement direction. The first fin portion 46A is in contact with the surface 21 of the right-side first battery cell 20A. 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.

[0105] 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 to extend in the 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 second alignment direction (upward direction). The second stopper portion 47B is formed to extend in the first alignment direction (downward direction). The second fin portion 47A is in contact with the surface 21 of the second battery cell 20B on the left side. 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.

[0106] 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 left side surface 21 of the second battery cell 20B.

[0107] The fourth bar portion 44 is provided with a fourth fin portion 49. The fourth fin portion 49 is formed extending in the first orthogonal direction (to the right in the figure) at a fourth angle θD inclined with respect to the second alignment direction (upward). The fourth fin portion 49 is in contact with the surface 21 of the right-side first battery cell 20A.

[0108] (Uncompressed state) As shown in FIG. 17, in the non-compressed 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 of the first bar portion 41. In the non-compressed 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 of the second bar portion 42. In the non-compressed 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 of the third bar portion 43. In the non-compressed 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 of 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 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.

[0109] 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 P between the first bar portion 41 and the second bar portion 42 (LA < P, LB < P). The sum of the first fin length LA and the second fin length LB is longer than the distance P between the first bar portion 41 and the second bar portion 42 (LA + LB > P).

[0110] 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 P between the first bar portion 41 and the third bar portion 43 (LC < P, LE < P). The sum of the third fin length LC and the fifth fin length LE is longer than the distance P between the first bar portion 41 and the third bar portion 43 (LC + LE > P).

[0111] The sixth fin length LF, which is the length of the second stopper portion 47B from the second bar portion 42, and the fourth fin length LD, which is the length of the fourth fin portion 49 from the fourth bar portion 44, are both shorter than the distance P between the second bar portion 42 and the fourth bar portion 44 (LF < P, LD < P). The sum of the sixth fin length LF and the fourth fin length LD is longer than the distance P between the second bar portion 42 and the fourth bar portion 44 (LF + LD > P).

[0112] The total of the projection length LZA in the arrangement direction (Z direction) of the first fin portion 46A and the projection length LZB of the second fin portion 47A is shorter than the interval P between the first bar portion 41 and the second bar portion 42 in the non-compressed state (LZA + LZB < P). Therefore, 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 low cost.

[0113] The total 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 P between the first bar portion 41 and the third bar portion 43 in the non-compressed state (LZC + LE < P). Therefore, 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 low cost.

[0114] The total of the projection length LZD in the arrangement 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 interval P between the second bar portion 42 and the fourth bar portion 44 in the non-compressed state (LZD + LF < P). Therefore, in the non-compressed state, a gap G3 is provided in the arrangement 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 are prevented from overlapping in the arrangement direction (Z direction). Such a spacer 13 can be manufactured at low cost.

[0115] (Compressed state) As shown in Figure 18, in the compressed state, the right side of the bar portion 40 is in contact with the surface 21 of the right first battery cell 20A. The left side of the bar portion 40 is in contact with the surface 21 of the left second battery cell 20B. In other words, in the compressed state, the bar portion 40 is compressed in the stacking direction (X direction) by being sandwiched between the surface 21 of the first battery cell 20A and the surface 21 of the second battery cell 20B. Furthermore, the bar portion 40 presses the surface 21 of the first battery cell 20A and the surface 21 of the second battery cell 20B away from each other due to the reaction force against this compression. As a result, contact between adjacent battery cells 20 is suppressed by the bar portion 40. And, between two vertically adjacent bar portions 40, a space 15 is formed in which the surfaces 21 of the battery cells 20 adjacent to the spacer 13 are separated.

[0116] As the right side surface of the first bar portion 41 is in contact with the surface 21 of the right first battery cell 20A, 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. Due to this pressure, the first fin portion 46A 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 46A extends downward along the surface 21 of the right first battery cell 20A. Then, due to the reaction force of its bending, the bent first fin portion 46A presses the surface 21 of the right first battery cell 20A to the right.

[0117] 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 upward 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.

[0118] 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.

[0119] The right side of the fourth bar portion 44 is in contact with the surface 21 of the right first battery cell 20A, causing the fourth fin portion 49 provided on the fourth bar portion 44 to be pressed to the right by the surface 21 of the right first battery cell 20A. Due to this pressure, the fourth fin portion 49 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 49 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.

[0120] 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 P 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 on the surface 21 that is not covered by the first fin portion 46A at the distance P 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 on the surface 21 that is not covered by the second fin portion 47A at the distance P between the first bar portion 41 and the second bar portion 42.

[0121] 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 P 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 on the surface 21 that is not covered by the first stopper portion 46B at the distance P 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 on the surface 21 that is not covered by the third fin portion 48 at the distance P between the first bar portion 41 and the third bar portion 43.

[0122] 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 P 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 on the surface 21 that is not covered by the second stopper portion 47B at the distance P 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 on the surface 21 that is not covered by the fourth fin portion 49 at the distance P between the second bar portion 42 and the fourth bar portion 44.

[0123] 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.

[0124] 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 P 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 L1 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 P 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.

[0125] Similarly, the sum of the first fin length LA of the first fin portion 46A and the second fin length LB of the second fin portion 47A is longer than the distance P 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 P 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.

[0126] 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 P 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 P 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.

[0127] Even if the battery cell 20 expands for any reason, 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. Therefore, the spacer 13 can prevent the flow rate of the cooling gas flowing into 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 into the space 15. Furthermore, even if the battery cell 20 expands for any reason, the third bar portion 33 and the fourth bar portion 34 can push the case 22 of the battery cell 20 in, and the electrode body 23 can be held in place.

[0128] Next, the effects of the fourth embodiment will be described. In addition to the effects of (1-1) of the first embodiment or (2-1) of the second embodiment, the following effects are also achieved. (4-1) 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. As a result, insulation can be ensured by the first fin portion 46A provided on the first bar portion 41 and the second fin portion 47A provided on the second bar portion 42 separately contacting both adjacent battery cells 20.

[0129] (4-2) 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.

[0130] (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.

[0131] Each of the above embodiments includes four bar sections. However, it may also include five or more bar sections. In the embodiments described above, the cross-sectional shape of the bar portion was rectangular. However, the cross-sectional shape of the bar portion may be other than rectangular.

[0132] 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.

[0133] 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]

[0134] 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 13D…Space forming part 14… End plate 15…Space 20…Battery cells 20A…First battery cell 20B…Second battery cell 21...face 22... Cases 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 A plurality of bar portions extending in the longitudinal direction along the battery cell and arranged at intervals from each other in an arrangement direction intersecting the longitudinal direction, A first fin portion extends from the bar portion having a predetermined thickness toward one of the battery cells and is in contact with the surface of the one of the battery cells, It has a second fin portion that extends from the bar portion having a predetermined thickness toward the other battery cell which is different from the one battery cell, and that is in contact with the surface of the other battery cell, The first fin portion and the second fin portion are separate fin portions. In each of the fin portions, the thickness at both ends in the longitudinal direction is greater than the thickness at the center in the longitudinal direction. 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 A plurality of bar portions extending in the longitudinal direction along the battery cell and arranged at intervals from each other in an arrangement direction intersecting the longitudinal direction, A first fin portion extends from the bar portion having a predetermined thickness toward one of the battery cells and is in contact with the surface of the one of the battery cells, It has a second fin portion that extends from the bar portion having a predetermined thickness toward the other battery cell which is different from the one battery cell, and that is in contact with the surface of the other battery cell, The direction perpendicular to the longitudinal direction and the arrangement direction is the thickness direction of the bar portion. The first fin portion and the second fin portion are separate fin portions. In the bar portion, the thickness of both ends in the longitudinal direction is greater than the thickness of the central part in the longitudinal direction. In each of the fin portions, the thickness of the central portion in the longitudinal direction is greater than the thickness of the ends in the longitudinal direction. Battery module.

3. The first fin portion and the second fin portion are provided on the same bar portion among the plurality of bar portions. The battery module according to claim 1 or 2.

4. 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 3.

5. 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. The battery module according to claim 1 or 2.

6. 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 device comprises two of the aforementioned second 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 5.

7. 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 5.

8. A spacer made of synthetic resin, which is placed between multiple battery cells that make up a battery module, Multiple bar sections are arranged at intervals from each other, and extend in the longitudinal direction intersecting the direction of arrangement, A first fin portion is provided from the bar portion having a predetermined thickness, and is formed to extend in a first orthogonal direction that is inclined with respect to the first arrangement direction in the arrangement direction and perpendicular to the arrangement direction, It has a second fin portion that is provided with a predetermined thickness from the bar portion and is formed to extend in the first orthogonal direction, inclined with respect to the second arrangement direction opposite to the first arrangement direction, The first fin portion and the second fin portion are separate fin portions. In each of the fin portions, the thickness at both ends in the longitudinal direction is greater than the thickness at the center in the longitudinal direction. Spacer.

9. A spacer made of synthetic resin, which is placed between multiple battery cells that make up a battery module, Multiple bar sections are arranged at intervals from each other, and extend in the longitudinal direction intersecting the direction of arrangement, A first fin portion is provided from the bar portion having a predetermined thickness, and is formed to extend in a first orthogonal direction that is inclined with respect to the first arrangement direction in the arrangement direction and perpendicular to the arrangement direction, It has a second fin portion that is provided with a predetermined thickness from the bar portion and is formed to extend in the first orthogonal direction, inclined with respect to the second arrangement direction opposite to the first arrangement direction, The direction perpendicular to the longitudinal direction and the arrangement direction is the thickness direction of the bar portion. The first fin portion and the second fin portion are separate fin portions. In the bar portion, the thickness of both ends in the longitudinal direction is greater than the thickness of the central part in the longitudinal direction. In each of the fin portions, the thickness of the central portion in the longitudinal direction is greater than the thickness of the ends in the longitudinal direction. Spacer.

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