Battery module and spacer

Abstract

To provide a battery module and a spacer which appropriately cool battery cells.SOLUTION: In a battery module, a plurality of battery cells 20 and spacers 13 which is arranged between the battery cells 20 and is made of a synthetic resin are alternately stacked. The spacer 13 has a plurality of bar parts 50 arrayed at intervals along the battery cells 20, a first fin part 56 which is inclined in a first array direction in an array direction in which the bar parts 50 are arrayed, is formed so as to extend to a side of the first battery cell 20A, and is brought into contact with a surface 21 of the first battery cell 20A, and a second fin part 57 which is inclined in a second array direction reverse to the first array direction, is formed so as to extend to a side of a second battery cell 20B different from the first battery cell 20A, and is brought into contact with the surface 21 of the second battery cell 20B. A cross sectional shape of the bar part 50 has a shape such that the first fin part 56 and the second fin part 57 are pressed to the battery cell 20, thereby the bar parts 50 are rotated, and thereby are brought into surface contact with the battery cell 20.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] In the battery module described in Patent Document 1, spacers are placed between the battery cells. The spacers have wall portions sandwiched between the main surfaces of the adjacent battery cells, and notches that penetrate the wall portions in the thickness direction are formed in the wall portions. By using such spacers and passing cooling gas through the notches, the temperature difference between the adjacent battery cells through the spacers is reduced. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-82170 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the technology described in Patent Document 1, there is a risk that the passageway for the cooling gas that penetrates the spacer in the thickness direction may become narrower than expected. That is, the internal pressure of the battery cells in the battery module may increase due to gas generated inside the case, causing them to expand. Part of the expanded battery cell may enter the passageway for the cooling gas provided in the spacer. In other words, if the battery cell expands, the passageway for the cooling gas provided in the spacer may become narrower than when the battery cell does not expand. This may result in inadequate cooling of the battery cell. [Means for solving the problem]

[0005] A battery module that solves the above problem is a battery module in which a plurality of battery cells and synthetic resin spacers that are placed between the battery cells are alternately stacked, wherein the spacers have a plurality of bar portions that are arranged at intervals along the battery cells, a first fin portion that is provided on the bar portions and is formed so as to extend toward one of the battery cells at an angle with respect to a first arrangement direction in which the bar portions are arranged, and contacts a surface of the one battery cell, and a second fin portion that is provided on the bar portions and is formed so as to extend toward the other battery cell that is different from the one battery cell at an angle with respect to a second arrangement direction that is opposite to the first arrangement direction, and contacts a surface of the other battery cell, and the cross-sectional shape of the bar portions is such that the bar portions rotate when the first fin portions and the second fin portions are pressed against the battery cells, thereby coming into surface contact with the battery cells.

[0006] According to the above configuration, the first fin portion contacts the surface of one of the battery cells, thereby ensuring an appropriate distance from the surface of the 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. Therefore, the spacer ensures an appropriate distance between adjacent battery cells. Therefore, heat is appropriately dissipated into the space between the battery cells, allowing the battery cells to be appropriately cooled. Furthermore, the cross-sectional shape of the bar portion is such that the bar portion rotates to come into surface contact with the battery cell. Therefore, when the first fin portion and the second fin portion are pressed against the battery cell, the bar portion rotates, preventing the corners of the bar portion from hitting the battery cell.

[0007] A battery module that solves the above problem is a battery module in which a plurality of battery cells and spacers made of synthetic resin that are arranged between the battery cells are alternately stacked, and the spacers have a plurality of bar portions arranged at intervals along the battery cells, a first fin portion that is provided on the bar portions and is formed so as to extend toward one of the battery cells at an angle with respect to a first arrangement direction in which the bar portions are arranged, and contacts a surface of the one battery cell, and a second fin portion that is provided on the bar portions and is formed so as to extend toward the other battery cell that is different from the one battery cell at an angle with respect to a second arrangement direction that is opposite to the first arrangement direction, and contacts a surface of the other battery cell, and the cross-sectional shape of the bar portions is circular.

[0008] According to the above configuration, the first fin portion contacts the surface of one of the battery cells, thereby ensuring an appropriate distance from the surface of the 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. Therefore, the spacer ensures an appropriate distance between adjacent battery cells. This allows heat to be appropriately dissipated into the space between the battery cells, allowing the battery cells to be appropriately cooled. Furthermore, the cross-sectional shape of the bar portion is circular. Therefore, even if the bar portion rotates as the first fin portion and the second fin portion are pressed against the battery cells, the curved surface of the bar portion faces the surface of the battery cell, preventing the bar portion from applying a local load to the battery cell.

[0009] In the above-mentioned battery module, it is preferable that the cross-sectional shape of the bar portion is elliptical, the long axis of the ellipse extends in the arrangement direction of the bar portions, and the long axis of the ellipse becomes inclined from the arrangement direction when the bar portions rotate.

[0010] According to the above configuration, the cross section of the bar portion is elliptical, and the portion of the outer periphery of the ellipse where the angle is small comes into contact with the battery cell, so the contact area between the bar portion and the battery cell can be made wider than with a circular shape.

[0011] A battery module that solves the above problem is a battery module in which a plurality of battery cells and synthetic resin spacers that are placed between the battery cells are alternately stacked, wherein the spacers have a plurality of bar portions that are arranged at intervals along the battery cells, a first fin portion that is provided on the bar portions and is formed so as to extend toward one of the battery cells at an angle with respect to a first arrangement direction in which the bar portions are arranged, and contacts a surface of the one battery cell, and a second fin portion that is provided on the bar portions and is formed so as to extend toward the other battery cell that is different from the one battery cell at an angle with respect to a second arrangement direction that is opposite to the first arrangement direction, and contacts a surface of the other battery cell, wherein the cross-sectional shape of the bar portions is a shape that includes two opposing sides, and the two opposing sides are parallel to the surfaces of the battery cells as the bar portions rotate when the first fin portions and the second fin portions are pressed against the battery cells.

[0012] According to the above configuration, the first fin portion contacts the surface of one of the battery cells, thereby ensuring an appropriate distance from the surface of the 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. Therefore, the spacer allows the appropriate distance between adjacent battery cells to be ensured. This allows appropriate heat dissipation into the space between the battery cells, allowing the battery cells to be appropriately cooled. Furthermore, the two opposing sides of the bar portion are parallel to the surfaces of the battery cells. Therefore, when the bar portion rotates as the first fin portion and the second fin portion are pressed against the battery cells, the surfaces of the bar portion and the surfaces of the battery cells become parallel, preventing the corners of the bar portion from hitting the battery cells.

[0013] The spacer that solves the above problem is a spacer made of synthetic resin and placed between multiple battery cells that make up a battery module, and has multiple bar portions arranged at intervals from each other, a first fin portion provided on a first bar portion included in the bar portions, the first fin portion being formed so as to extend in a first orthogonal direction that is inclined with respect to a first arrangement direction in which the bar portions are arranged and perpendicular to the arrangement direction, and a second fin portion being provided on the first bar portion, the second fin portion being formed so as to extend in the first orthogonal direction and inclined with respect to a second arrangement direction that is opposite to the first arrangement direction, and the cross-sectional shape of the bar portion is such that when the first fin portion and the second fin portion are pressed against the battery cell, the bar portion rotates to come into surface contact with the battery cell.

[0014] According to the above configuration, the first fin portion contacts the surface of one of the battery cells, thereby ensuring an appropriate distance from the surface of the 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. Therefore, the spacer can ensure an appropriate distance between adjacent battery cells. Therefore, heat is dissipated appropriately into the space between the battery cells, and the battery cells can be cooled appropriately. Furthermore, the first fin portion contacts the surface of one of the battery cells, thereby ensuring an appropriate distance from the surface of the 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. Therefore, the spacer can ensure an appropriate distance between adjacent battery cells. Therefore, heat is dissipated appropriately into the space between the battery cells, and the battery cells can be cooled appropriately. Furthermore, the cross-sectional shape of the bar portion is such that the bar portion rotates to come into surface contact with the battery cells. This prevents the bar portion from rotating and the corners of the bar portion from hitting the battery cell when the first fin portion and the second fin portion are pressed against the battery cell.

[0015] The spacer that solves the above problem is a spacer made of synthetic resin and placed between multiple battery cells that make up a battery module, and has multiple bar portions arranged at intervals from each other, a first fin portion provided on a first bar portion included in the bar portions, and formed so as to extend in a first orthogonal direction that is inclined with respect to a first arrangement direction in which the bar portions are arranged and perpendicular to the arrangement direction, and a second fin portion provided on the first bar portion, and formed so as to extend in the first orthogonal direction that is inclined with respect to a second arrangement direction that is opposite to the first arrangement direction, and the cross-sectional shape of the bar portions is circular.

[0016] According to the above configuration, the first fin portion contacts the surface of one of the battery cells, thereby ensuring an appropriate distance from the surface of the 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. Therefore, the spacer ensures an appropriate distance between adjacent battery cells. This allows heat to be appropriately dissipated into the space between the battery cells, allowing the battery cells to be appropriately cooled. Furthermore, the cross-sectional shape of the bar portion is circular. Therefore, even if the bar portion rotates as the first fin portion and the second fin portion are pressed against the battery cells, the curved surface of the bar portion faces the surface of the battery cell, preventing the bar portion from applying a local load to the battery cell.

[0017] Regarding the above-mentioned spacer, it is preferable that the cross-sectional shape of the bar portion is elliptical, the long axis of the ellipse extends in the arrangement direction of the bar portions, and the long axis of the ellipse becomes inclined from the arrangement direction when the bar portions rotate.

[0018] According to the above configuration, the cross section of the bar portion is elliptical, and the portion of the outer periphery of the ellipse where the angle is small comes into contact with the battery cell, so the contact area between the bar portion and the battery cell can be made wider than with a circular shape.

[0019] The spacer that solves the above problem is a spacer made of synthetic resin and placed between multiple battery cells that make up a battery module, and has multiple bar portions arranged at intervals from each other, a first fin portion provided on a first bar portion included in the bar portions, the first fin portion being formed so as to extend in a first orthogonal direction that is inclined with respect to a first arrangement direction in which the bar portions are arranged and perpendicular to the arrangement direction, and a second fin portion being provided on the first bar portion, the second fin portion being formed so as to extend in the first orthogonal direction and inclined with respect to a second arrangement direction that is opposite to the first arrangement direction, and the cross-sectional shape of the bar portion is a shape that includes two opposing sides, and when the first fin portion and the second fin portion are pressed against the battery cell, the bar portion rotates so that the two opposing sides become parallel to the surface of the battery cell.

[0020] According to the above configuration, the first fin portion contacts the surface of one of the battery cells, thereby ensuring an appropriate distance from the surface of the 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. Therefore, the spacer ensures an appropriate distance between adjacent battery cells. This allows heat to be appropriately dissipated into the space between the battery cells, allowing the battery cells to be appropriately cooled. Furthermore, the two opposing sides of the bar portion are parallel to the surfaces of the battery cells. Therefore, when the bar portion rotates as the first fin portion and the second fin portion are pressed against the battery cells, the surfaces of the bar portion and the surfaces of the battery cells become parallel, preventing the corners of the bar portion from hitting the battery cells. [Effects of the Invention]

[0021] According to the present invention, the battery cells can be cooled appropriately. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a perspective view showing a schematic configuration of a battery module according to a first embodiment. [Figure 2] 2 is a cross-sectional view of the battery module of the embodiment taken along line 2-2 of FIG. 1. [Figure 3]FIG. 2 is a perspective view of the spacer of the embodiment. [Figure 4] 4 is a cross-sectional view of a space forming portion of the spacer in an uncompressed state according to the embodiment; FIG. [Figure 5] 4 is a cross-sectional view of a space forming portion of the spacer in a compressed state according to the embodiment. FIG. [Figure 6] FIG. 10 is a cross-sectional view of a space forming portion of a spacer in a non-compressed state according to a second embodiment. [Figure 7] 4 is a cross-sectional view of a space forming portion of the spacer in a compressed state according to the embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0023] (First embodiment) A first embodiment of a battery module and a spacer will be described below with reference to FIGS.

[0024] (Battery module 10) As shown in FIG. 1 , the battery module 10 has a lower case 11 and multiple battery cells 20 housed within it. The lower case 11 is a box-shaped member with an open top. The battery cells 20 have a flattened rectangular parallelepiped outer shape. The multiple battery cells 20 are stacked and arranged within the lower case 11. Each battery cell 20 has a surface in the X direction, which is the stacking direction of the battery cells 20. Surface 21 of the battery cell 20 is the largest outer surface. The battery module 10 houses two rows of battery groups each made up of multiple stacked battery cells 20. The direction in which the rows of battery groups of battery cells 20 are arranged is the Y direction. The direction toward the top of the lower case 11 is the Z direction. Bus bars, pole terminals, an upper case, etc. are actually attached to the battery module 10, but these are omitted from the illustration.

[0025] As shown in FIG. 2, the lower case 11 has a floor portion 11A and an end wall portion 11B. The floor portion 11A is a portion of the lower case 11 located below the multiple battery cells 20. The end wall portion 11B is a portion 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, the spacers 13 are arranged between the battery cells 20. End plates 14 are sandwiched between the battery cells 20 on both ends and the end wall portions 11B. The spacers 13 and end plates 14 are made of synthetic resin. The spacers 13 and end plates 14 are insulating and have a certain degree of flexibility.

[0026] The battery cells 20, spacers 13, and end plates 14 are constrained by the end wall portions 11B at both ends in the stacking direction (X direction). As a result, the battery cells 20, spacers 13, and end plates 14 are subjected to a compressive load in the stacking direction (X direction). When compressed and housed in the battery module 10, the battery cells 20, spacers 13, and end plates 14 are compressed in the stacking direction (X direction) more than when they are uncompressed.

[0027] (Spacer 13) 3, the spacer 13 has a space-forming portion 13C. The space-forming portion 13C is provided in the center portion of the spacer 13. The space-forming portion 13C is a portion that forms a space between the battery cells 20 located on both sides of the spacer 13.

[0028] The spacer 13 has a plurality of bar portions 50 in the space forming portion 13C. The bar portions 50 extend in the longitudinal direction (Y direction) of the surface 21 of the battery cell 20. The plurality of bar portions 50 are arranged at intervals from one another in the vertical direction (Z direction) along the surface 21 of the battery cell 20. Fin portions 55 are provided on the plurality of bar portions 50. The space forming portion 13C is composed of the bar portions 50 and the fin portions 55.

[0029] (Space forming part 13C) Next, the space forming portion 13C will be described in detail with reference to Figures 4 and 5. Figures 4 and 5 are cross-sectional views of the space forming portion 13C of the spacer 13. Figure 4 shows the space forming portion 13C in an uncompressed state together with the adjacent battery cells 20 on both sides. Figure 5 shows the space forming portion 13C in a compressed state together with the adjacent battery cells 20 on both sides.

[0030] As shown in FIG. 4 , the bar portion 50 includes, 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 cross-sectional shape of the bar portions 50 in the stacking direction (X direction) is such that the first fin portion 56 and the second fin portion 57 are pressed against the battery cell 20, causing the bar portion 50 to rotate and come into surface contact with the battery cell 20. Specifically, the cross-sectional shape of the bar portion 50 is elliptical. The long axis of the ellipse of the bar portion 50 extends in the arrangement direction of the bar portions 50, and as the bar portion 50 rotates, the long axis of the ellipse becomes inclined from the arrangement direction (Z direction). When the bar portion 50 is not compressed, the long axis of the ellipse coincides with the arrangement direction (Z direction). Note that the cross-sectional shape of the bar portion 50 may also be circular. The fin portion 55 includes a first fin portion 56, a second fin portion 57, a third fin portion 58, and a fourth fin portion 59.

[0031] 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 inclined at a first angle θA with respect to a first arrangement direction (upward direction) in the arrangement direction (Z direction) in which the bar portions 50 are arranged, and extends in a first orthogonal direction (rightward in the figure) perpendicular to the arrangement direction (Z direction). The second fin portion 57 is inclined at a second angle θB with respect to a second arrangement direction (downward direction) opposite to the first arrangement direction, and extends in a second orthogonal direction (leftward in the figure) opposite to the first orthogonal direction. The first fin portion 56 contacts the surface 21 of the first battery cell 20A on the right side in the figure. The second fin portion 57 contacts 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.

[0032] A second fin portion 57 is provided on the third bar portion 53. The second fin portion 57 is inclined at a second angle θB with respect to the second arrangement direction (downward) and extends in a second orthogonal direction (leftward in the figure). The second fin portion 57 contacts the surface 21 of the second battery cell 20B on the left side.

[0033] A first fin portion 56 is provided on the fourth bar portion 54. The first fin portion 56 is inclined at a first angle θA with respect to the first arrangement direction (upward) and extends in a first orthogonal direction (rightward in the figure). The first fin portion 56 contacts the surface 21 of the first battery cell 20A on the right side.

[0034] (uncompressed state) As shown in FIG. 4 , in the uncompressed state, the tip of the first fin portion 56 on the first bar portion 51 protrudes beyond the first bar portion 51 toward the first battery cell 20A on the right side in the figure. In the uncompressed state, the tip of the second fin portion 57 on the first bar portion 51 protrudes beyond the first bar portion 51 toward the second battery cell 20B on the left side in the figure. In the uncompressed state, the tip of the first fin portion 56 on the second bar portion 52 protrudes beyond the second bar portion 52 toward the first battery cell 20A on the right side. In the uncompressed state, the tip of the second fin portion 57 on the second bar portion 52 protrudes beyond the second bar portion 52 toward the second battery cell 20B on the left side. The tip of the second fin portion 57 on the third bar portion 53 protrudes beyond the third bar portion 53 toward the second battery cell 20B on the left side. The tip of the first fin portion 56 provided on the fourth bar portion 54 protrudes further toward the first battery cell 20A on the right side than the fourth bar portion 54. The first bar portion 51, the second bar portion 52, the third bar portion 53, and the fourth bar portion 54 do not contact 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.

[0035] 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 interval 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 of the same length (LA = LB). The sum of the first fin length LA and the second fin length LB is longer than the interval P between the first bar portion 51 and the third bar portion 53 (LA + LB > P).

[0036] 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 interval 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 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 first bar portion 51 and the second bar portion 5 (LB + LA > P).

[0037] 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).

[0038] The sum of the projection lengths LZA and LZB in the arrangement direction (Z direction) of the first fin portion 56 and 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). Therefore, 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. As a result, 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.

[0039] The total 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 first bar portion 51 and the second bar portion 52 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 are prevented from overlapping in the arrangement direction (Z direction). Such a spacer 13 can be manufactured at a low cost.

[0040] The total 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 are prevented from overlapping in the arrangement direction (Z direction). Such a spacer 13 can be manufactured at a low cost.

[0041] (Compressed state) As shown in FIG. 5, in the compressed state, the right side surface of the bar portion 50 is in contact with the surface 21 of the first battery cell 20A on the right side. The surface 21 of the second battery cell 20B on the left side 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 of the second battery cell 20B 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 in which the surfaces 21 of the battery cells 20 adjacent to both sides of the spacer 13 are separated is formed between two adjacent bar portions 50 vertically.

[0042] Because the surface 21 of the first right 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 first right battery cell 20A. Due to this pressing, the first fin portion 56 is bent more to the left than in the uncompressed state along the surface 21 of the first right battery cell 20A. In this bent state, the first fin portion 56 extends upward along the surface 21 of the first right battery cell 20A. In this bent state, the first fin portion 56 presses the surface 21 of the first right battery cell 20A to the right due to the reaction force of the bending.

[0043] Because the surface 21 of the second left battery cell 20B is in contact with the left side surface of the first bar portion 51, the second fin portion 57 provided on the first bar portion 51 is pressed to the right by the surface 21 of the second left battery cell 20B. Due to this pressing, the second fin portion 57 is bent more to the right than in the uncompressed state along the surface 21 of the second left battery cell 20B. In this bent state, the second fin portion 57 extends downward along the surface 21 of the second left battery cell 20B. In this bent state, the second fin portion 57 presses the surface 21 of the second left battery cell 20B to the left due to the reaction force of the bending.

[0044] Because the surface 21 of the first right battery cell 20A is in contact with the right side surface of the second bar portion 52, the first fin portion 56 provided on the second bar portion 52 is pressed to the right by the surface 21 of the first right battery cell 20A. Due to this pressing, the first fin portion 56 is bent along the surface 21 of the first right battery cell 20A and is bent more to the left than when in an uncompressed state. In this bent state, the first fin portion 56 extends upward along the surface 21 of the first right battery cell 20A. In this bent state, the first fin portion 56 presses the surface 21 of the first right battery cell 20A to the right due to the reaction force of the bending.

[0045] Because the surface 21 of the second left battery cell 20B is in contact with the left side surface of the second bar portion 52, the second fin portion 57 provided on the second bar portion 52 is pressed to the right by the surface 21 of the second left battery cell 20B. Due to this pressing, the second fin portion 57 is bent more to the right than in the uncompressed state along the surface 21 of the second left battery cell 20B. In this bent state, the second fin portion 57 extends downward along the surface 21 of the second left battery cell 20B. In this bent state, the second fin portion 57 presses the surface 21 of the second left battery cell 20B to the left due to the reaction force of the bending.

[0046] Because the surface 21 of the second left battery cell 20B is in contact with the left side surface of the third bar portion 53, the second fin portion 57 provided on the third bar portion 53 is pressed to the right by the surface 21 of the second left battery cell 20B. Due to this pressing, the second fin portion 57 is bent more to the right than in the uncompressed state along the surface 21 of the second left battery cell 20B. In this bent state, the second fin portion 57 extends downward along the surface 21 of the second left battery cell 20B. In this bent state, the second fin portion 57 presses the surface 21 of the second left battery cell 20B to the left due to the reaction force of the bending.

[0047] Because the surface 21 of the first right battery cell 20A is in contact with the right side surface of the fourth bar portion 54, the first fin portion 56 provided on the fourth bar portion 54 is pressed to the left by the surface 21 of the first right battery cell 20A. Due to this pressing, the first fin portion 56 is bent more to the left than in the uncompressed state along the surface 21 of the first right battery cell 20A. In this bent state, the first fin portion 56 extends upward along the surface 21 of the first right battery cell 20A. In this bent state, the first fin portion 56 presses the surface 21 of the first right battery cell 20A to the right due to the reaction force of the bending.

[0048] As described 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, there is a portion of the surface 21 of the first right-side battery cell 20A that is not covered by the first fin portion 56 within the distance P between the first bar portion 51 and the third bar portion 53. Similarly, there is a portion of the surface 21 of the second left-side battery cell 20B that is not covered by the second fin portion 57 within the distance P between the first bar portion 51 and the third bar portion 53.

[0049] 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. Therefore, there is a portion of the surface 21 of the first right-side battery cell 20A that is not covered by the second fin portion 57 within the distance P between the first bar portion 51 and the second bar portion 52. Furthermore, there is a portion of the surface 21 of the second left-side battery cell 20B that is not covered by the first fin portion 56 within the distance P between the first bar portion 51 and the second bar portion 52.

[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 second bar portion 52 and the fourth bar portion 54. Therefore, there is a portion of the surface 21 of the second left battery cell 20B that is not covered by the second fin portion 57 within the distance P between the second bar portion 52 and the fourth bar portion 54. Also, there is a portion of the surface 21 of the first right battery cell 20A that is not covered by the first fin portion 56 within the distance P between the second bar portion 52 and the fourth bar portion 54.

[0051] Therefore, the surfaces 21 of the battery cells 20 on both sides of the spacer 13 have portions exposed to the space 15 at the interval P between the bar portions 50. In other words, when the battery cells 20 on both sides of the spacer 13 generate heat, they can dissipate the heat into the space 15. The space 15 is a passageway for cooling gas in the battery module 10, through which gas for cooling the battery cells 20 flows. As a result, the spacer 13 can cool the battery cells 20 on both sides while preventing the temperature difference between the adjacent battery cells 20 from becoming too large.

[0052] As described 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 arrangement direction (Z direction). That is, there is an overlap L between the tip of the first fin portion 56 and the tip of the second fin portion 57. Therefore, the first fin portion 56 presses at least a region of the first right battery cell 20A that faces a region of the second left battery cell 20B that is not pressed by the second fin portion 57. The second fin portion 57 presses at least a region of the second left battery cell 20B that faces a region of the first right battery cell 20A that is not pressed by the first fin portion 56. In other words, the battery cells 20 on either side of the spacer 13 have no gap in the arrangement direction (Z direction) at the interval P between the bar portions 50, 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 on either side of 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 their respective first fin portions 56 and second fin portions 57, 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 on either side. This allows the spacer 13 to reliably maintain insulation between the adjacent battery cells 20 on either side.

[0053] 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 arrangement direction (Z direction). That is, there is an overlap L between the tip of the second fin portion 57 and the tip of the first fin portion 56. Therefore, the second fin portion 57 presses at least a region of the first right battery cell 20A that faces a region of the second left battery cell 20B that is not pressed by the first fin portion 56. The first fin portion 56 presses at least a region of the second left battery cell 20B that faces a region of the first right battery cell 20A that is not pressed by the second fin portion 57. In other words, the battery cells 20 on either side of the spacer 13 have no gap in the arrangement direction (Z direction) at the interval P between the bar portions 50, 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 on either side of 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 their respective second fin portions 57 and first fin portions 56, 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. This allows the spacer 13 to 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 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 arrangement direction (Z direction). That is, there is an overlap L between the tip of the second fin portion 57 and the tip of the first fin portion 56. Therefore, the first fin portion 56 presses at least a region of the right-side first battery cell 20A that faces a region of the left-side second battery cell 20B that is not pressed by the second fin portion 57. The second fin portion 57 presses at least a region of the left-side second battery cell 20B that faces a region of the right-side first battery cell 20A that is not pressed by the first fin portion 56. In other words, the battery cells 20 on either side of the spacer 13 have no gap in the arrangement direction (Z direction) at the interval P between the bar portions 50, 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 on either side of 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 their respective second fin portions 57 and first fin portions 56, 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. This allows the spacer 13 to reliably maintain insulation between the adjacent battery cells 20 on either side.

[0055] 5, when the tip end of the fin portion 55 is pressed by the surfaces 21 of the adjacent battery cells 20 on either side, the base end of the fin portion 55 bends and the bar portion 50 rotates slightly counterclockwise (in the direction of the arrow in the figure) as the fin portion 55 is pressed. Because the cross-sectional shape of the bar portion 50 is elliptical, even if the bar portion 50 rotates, the corners of the bar portion 50 do not come into contact with the battery cells 20. This prevents the bar portion 50 from rotating and generating a local load on the battery cells 20 due to the bar portion 50.

[0056] Even if the battery cells 20 expand for some reason, the spacers 13 can prevent the battery cells 20 from entering the spaces 15 by the pressure applied by the first fin portions 56 and the second fin portions 57 to the battery cells 20. In other words, even if the battery cells 20 expand, the spacers 13 can prevent the length of the spaces 15 in the stacking direction (X direction) from becoming narrower, thereby ensuring the appropriate size of the spaces 15. Therefore, the spacers 13 can prevent the flow rate of the cooling gas flowing in the spaces 15 from decreasing due to the expansion of the battery cells 20. Therefore, the spacers 13 can prevent a decrease in the cooling function of the cooling gas flowing in the spaces 15 for the battery cells 20 from decreasing.

[0057] Next, the effects of the first embodiment will be described. (1-1) The first fin portion 56 contacts the surface 21 of the first battery cell 20A, thereby ensuring an appropriate distance from the surface 21 of the first battery cell 20A. The second fin portion 57 contacts the surface 21 of the second battery cell 20B, thereby ensuring an appropriate distance from the surface 21 of the second battery cell 20B. Therefore, the spacer 13 can ensure an appropriate distance between adjacent battery cells 20. As a result, heat is appropriately dissipated into the space between the battery cells 20, allowing the battery cells 20 to be appropriately cooled. Furthermore, the cross-sectional shape of the bar portion 50 is such that the bar portion 50 comes into surface contact with the battery cell 20 when rotated. Therefore, when the first fin portion 56 and the second fin portion 57 are pressed against the battery cell 20, the bar portion 50 rotates, preventing the corners of the bar portion 50 from hitting the battery cell 20.

[0058] (1-2) The cross-sectional shape of the bar portion 50 is circular. Therefore, even if the bar portion 50 rotates as the first fin portion 56 and the second fin portion 57 are pressed against the battery cell 20, the curved surface of the bar portion 50 faces the surface 21 of the battery cell 20, preventing the bar portion 50 from applying a local load to the battery cell 20.

[0059] (1-3) The cross-sectional shape of the bar portion 50 is elliptical, and the portion of the outer periphery of the ellipse where the angle is small comes into contact with the battery cell 20, so the contact area between the bar portion 50 and the battery cell 20 can be made wider than with a circular shape.

[0060] (Second embodiment) A second embodiment of the battery module and spacer will be described below with reference to Figures 6 and 7. The battery module and spacer of this embodiment differ from those of the first embodiment in terms of the space-forming portion. The following description will focus on the differences from the first embodiment.

[0061] (Space forming part 13A) Next, the space forming portion 13A will be described in detail with reference to Figures 6 and 7. Figures 6 and 7 are cross-sectional views of the space forming portion 13A of the spacer 13. Figure 6 shows the space forming portion 13A in an uncompressed state together with the adjacent battery cells 20 on either side. Figure 7 shows the space forming portion 13A in a compressed state together with the adjacent battery cells 20 on either side.

[0062] As shown in FIG. 6 , the bar portion 60 has, from top to bottom, a third bar portion 63, a first bar portion 61, a second bar portion 62, and a fourth bar portion 64. The cross-sectional shape of these bar portions 60 in the stacking direction (X direction) is such that the first fin portion 66 and the second fin portion 67 are pressed against the battery cell 20, causing the bar portion 60 to rotate and come into surface contact with the battery cell 20. Specifically, the cross-sectional shape of the bar portion 60 is a shape that includes two opposing sides. The two opposing sides of the cross section of the bar portion 60 are parallel to the surface of the battery cell 20, as a result of the bar portion 60 rotating when the first fin portion 66 and the second fin portion 67 are pressed against the battery cell 20. The fin portion 65 has a first fin portion 66, a second fin portion 67, a third fin portion 68, and a fourth fin portion 69.

[0063] The first bar portion 61 is provided with a first fin portion 66 and a second fin portion 67. The first fin portion 66 is similar to the first fin portion 56 of the first embodiment. The second fin portion 67 is similar to the second fin portion 57 of the first embodiment.

[0064] The second bar portion 62 is provided with a third fin portion 68 and a fourth fin portion 69. The third fin portion 68 is similar to the third fin portion 58 of the first embodiment. The fourth fin portion 69 is similar to the fourth fin portion 59 of the first embodiment.

[0065] The third bar portion 63 is provided with a fourth fin portion 69. The fourth fin portion 69 is similar to the fourth fin portion 59 of the first embodiment. The fourth bar portion 64 is provided with a first fin portion 66. The first fin portion 66 is similar to the first fin portion 56 of the first embodiment.

[0066] 7, when the tip end of the fin portion 65 is pressed by the surfaces 21 of the adjacent battery cells 20, the base end of the fin portion 65 bends and the bar portion 60 rotates slightly counterclockwise (in the direction of the arrow in the figure) as the fin portion 65 is pressed. Because the cross-sectional shape of the bar portion 60 includes two opposing sides, even if the bar portion 60 rotates, it is possible to prevent the corners of the bar portion 60 from hitting the battery cells 20. This makes it possible to prevent the bar portion 60 from rotating and causing local loads on the battery cells 20 due to the corners of the bar portion 60.

[0067] Even if the battery cell 20 expands for some reason, the spacer 13 can prevent the battery cell 20 from entering the space 15 by the first fin portion 66, the second fin portion 67, the third fin portion 68, and the fourth fin portion 69 pressing against the battery cell 20. 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 becoming narrower, thereby ensuring an appropriate space 15. Therefore, the spacer 13 can prevent the flow rate of the cooling gas flowing in the space 15 from decreasing due to the expansion of the battery cell 20. Therefore, the spacer 13 can prevent a decrease in the cooling function of the cooling gas flowing in the space 15 for the battery cell 20 from decreasing.

[0068] Next, the effects of the second embodiment will be described. (2-1) The first fin portion 66 and the second fin portion 67 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. The third fin portion 68 and the fourth fin portion 69 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. Therefore, the spacer 13 can appropriately ensure the distance between adjacent battery cells 20. As a result, heat is appropriately dissipated into the space between the battery cells 20, allowing the battery cells 20 to be appropriately cooled. Furthermore, the cross-sectional shape of the bar portion 60 is such that the bar portion 60 comes into surface contact with the battery cell 20 when rotated. Therefore, when the first fin portion 66 and the second fin portion 67 are pressed against the battery cell 20, the bar portion 60 rotates, preventing the corners of the bar portion 60 from hitting the battery cell 20.

[0069] (2-2) Two opposing sides of the bar portion 60 are parallel to the surface of the battery cell 20. Therefore, when the bar portion 60 rotates as the first fin portion 66 and the second fin portion 67 are pressed against the battery cell 20, the surface of the bar portion 60 and the surface 21 of the battery cell 20 become parallel, preventing the corners of the bar portion 60 from hitting the battery cell 20.

[0070] (Other embodiments) The above-described embodiments can be modified as follows: The above-described embodiments and the following modifications can be combined with each other within the scope of technical compatibility.

[0071] In the above embodiments, the arrangement direction of the bar portions is the vertical direction (Z direction) of the battery cells 20. However, the arrangement direction of the bar portions may also be the width direction (Y direction) of the battery cells 20. Furthermore, the number of bar portions can be changed as appropriate.

[0072] The above embodiments are applicable to any type of battery, such as a nickel-metal hydride secondary battery or a lithium-ion secondary battery, and there is no particular limitation thereon. [Explanation of symbols]

[0073] 10...Battery module 11...Lower case 11A...Floor section 11B...End wall section 13...Spacer 13A…Space forming part 13B…Space forming part 13C…Space forming part 14...End plate 15…Space 20...Battery cell 20A…1st battery cell 20B...2nd battery cell 21...face 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 part 57...Second fin part 60...Bar section 61...First bar section 62...Second bar section 63...Third bar section 64...4th bar section 65...Fin section 66...First fin part 67...Second fin part LA...First fin length LB: Second fin length

Claims

1. A battery module in which a plurality of battery cells and synthetic resin spacers disposed between the battery cells are alternately stacked, The spacer is a plurality of bar portions arranged at intervals along the battery cell; a first fin portion provided on the bar portion, extending toward one of the battery cells at an angle with respect to a first arrangement direction in the arrangement direction of the bar portions, and in contact with a surface of the one of the battery cells; a second fin portion provided on the bar portion, inclined with respect to a second arrangement direction opposite to the first arrangement direction, extending toward the other battery cell different from the one battery cell, and in contact with a surface of the other battery cell; The cross-sectional shape of the bar portion is such that the first fin portion and the second fin portion are pressed against the battery cell, causing the bar portion to rotate and come into surface contact with the battery cell. Battery module.

2. A battery module in which a plurality of battery cells and synthetic resin spacers disposed between the battery cells are alternately stacked, The spacer is a plurality of bar portions arranged at intervals along the battery cell; a first fin portion provided on the bar portion, extending toward one of the battery cells at an angle with respect to a first arrangement direction in the arrangement direction of the bar portions, and in contact with a surface of the one of the battery cells; a second fin portion provided on the bar portion, inclined with respect to a second arrangement direction opposite to the first arrangement direction, extending toward the other battery cell different from the one battery cell, and in contact with a surface of the other battery cell; The cross-sectional shape of the bar portion is circular. Battery module.

3. The cross-sectional shape of the bar portion is elliptical, The bar portion has a major axis of the ellipse extending in the arrangement direction of the bar portions, and when the bar portion rotates, the major axis of the ellipse is inclined from the arrangement direction. The battery module according to claim 2 .

4. A battery module in which a plurality of battery cells and synthetic resin spacers disposed between the battery cells are alternately stacked, The spacer is a plurality of bar portions arranged at intervals along the battery cell; a first fin portion provided on the bar portion, extending toward one of the battery cells at an angle with respect to a first arrangement direction in the arrangement direction of the bar portions, and in contact with a surface of the one of the battery cells; a second fin portion provided on the bar portion, inclined with respect to a second arrangement direction opposite to the first arrangement direction, extending toward the other battery cell different from the one battery cell, and in contact with a surface of the other battery cell; The cross-sectional shape of the bar portion is a shape including two opposing sides, The two opposing sides are parallel to the surface of the battery cell as a result of the bar portion rotating when the first fin portion and the second fin portion are pressed against the battery cell. Battery module.

5. A spacer made of synthetic resin and arranged between a plurality of battery cells that constitute a battery module, A plurality of bar portions arranged at intervals from each other; a first fin portion provided on a first bar portion included in the bar portion, the first fin portion being formed to extend in a first orthogonal direction perpendicular to the arrangement direction and inclined with respect to a first arrangement direction in which the bar portions are arranged; a second fin portion provided on the first bar portion and extending in the first orthogonal direction at an angle with respect to a second arrangement direction opposite to the first arrangement direction; The cross-sectional shape of the bar portion is such that when the first fin portion and the second fin portion are pressed against the battery cell, the bar portion rotates to come into surface contact with the battery cell. Spacer.

6. A spacer made of synthetic resin and arranged between a plurality of battery cells that constitute a battery module, A plurality of bar portions arranged at intervals from each other; a first fin portion provided on a first bar portion included in the bar portion, the first fin portion being formed to extend in a first orthogonal direction perpendicular to the arrangement direction and inclined with respect to a first arrangement direction in which the bar portions are arranged; a second fin portion provided on the first bar portion and extending in the first orthogonal direction at an angle with respect to a second arrangement direction opposite to the first arrangement direction; The cross-sectional shape of the bar portion is circular. Spacer.

7. The cross-sectional shape of the bar portion is elliptical, The bar portion has a major axis of the ellipse extending in the arrangement direction of the bar portions, and when the bar portion rotates, the major axis of the ellipse is inclined from the arrangement direction. The spacer according to claim 6 .

8. A spacer made of synthetic resin and arranged between a plurality of battery cells that constitute a battery module, A plurality of bar portions arranged at intervals from each other; a first fin portion provided on a first bar portion included in the bar portion, the first fin portion being formed to extend in a first orthogonal direction perpendicular to the arrangement direction and inclined with respect to a first arrangement direction in which the bar portions are arranged; a second fin portion provided on the first bar portion and extending in the first orthogonal direction at an angle with respect to a second arrangement direction opposite to the first arrangement direction; The cross-sectional shape of the bar portion is a shape including two opposing sides, When the first fin portion and the second fin portion are pressed against the battery cell, the bar portion rotates and becomes parallel to the surface of the battery cell. Spacer.

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