Power storage device

Abstract

To inhibit variations in a thickness of a heat-transfer agent located between a power storage module and a lower case.SOLUTION: A power storage device includes: a power storage module 10; a lower case mounted with the power storage module 10; and a bracket 21 for fixing the power storage module 10 and the lower case to each other. The bracket 21 includes: a first fixing part 201 fixed to a side surface 11a of the power storage module 10; and a second fixing part 202 extending from the first fixing part 201 in a direction away from the power storage module 10 and fixed to the lower case. The second fixing part 202 has a plurality of recessed parts. Each of the recessed parts has a hole into which a fastening member is inserted. The recessed parts include two first recessed parts 221 having a first rigidity and at least one second recessed part 222 having a second rigidity lower than the first rigidity.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to an electricity storage device. [Background technology]

[0002] For example, Japanese Patent Application Laid-Open No. 2016-212980 (Patent Document 1) discloses a battery pack (electricity storage device) that can maintain contact of a heat transfer plate with a housing even if the position of a battery cell is misaligned with respect to the housing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-212980 Summary of the Invention [Problem to be solved by the invention]

[0004] In some cases, the cooling device is located below the power storage device and a thermally conductive agent is applied between the power storage module and the lower case. In such cases, if there is variation in the shape or rigidity of the bracket that secures the power storage module to the lower case, the power storage module will tilt relative to the lower case. This will result in variations in the thickness of the thermally conductive agent, which will deteriorate the cooling performance.

[0005] An object of the present disclosure is to suppress variations in the thickness of a thermally conductive agent positioned between an electricity storage module and a lower case. [Means for solving the problem]

[0006] An energy storage device according to one aspect of the present disclosure includes an energy storage module, a lower case on which the energy storage module is mounted, and a bracket that secures the energy storage module to the lower case. The bracket includes a first fixing portion secured to a side surface of the energy storage module and a second fixing portion that extends from the first fixing portion in a direction away from the energy storage module and is secured to the lower case. A plurality of recesses are formed in the second fixing portion. Each of the plurality of recesses has a hole into which a fastening member is inserted. The plurality of recesses include two first recesses having a first rigidity and at least one second recess having a second rigidity lower than the first rigidity.

[0007] Preferably, reinforcing portions are formed within the two first recesses.

[0008] Preferably, at least one second recess is provided with a notch.

[0009] Preferably, the thickness of the portion of the bracket that defines the at least one second recess is thinner than the thickness of the portions that define the two first recesses.

[0010] Preferably, the side surfaces of the power storage module have a first side surface and a second side surface aligned in the first direction. When the power storage module and the bracket are viewed from a position spaced above the power storage module and the bracket, the two first recesses are disposed at positions symmetrical with respect to an imaginary line that passes through the center of gravity of the power storage module and extends in the first direction. [Effects of the Invention]

[0011] According to the present disclosure, it is possible to suppress variations in the thickness of the thermally conductive agent located between the power storage module and the lower case. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a side view schematically illustrating a vehicle including an electricity storage device according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] 1A and 1B are diagrams showing a bracket according to the present embodiment. [Figure 4] 9 is a diagram showing the power storage module 10 and a bracket 21 fixed to a base 911. FIG. [Figure 5] 9A and 9B are diagrams showing the power storage module 10 and the bracket 22 fixed to the base 912. FIG. [Figure 6] 2 is a plan view schematically showing the storage module 10 and brackets 21 and 22. FIG. [Figure 7] FIG. 10 is a diagram showing a bracket according to a first modified example. [Figure 8] FIG. 10 is a view showing a bracket according to a second modification. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments and modifications according to the present disclosure will be described with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated. Note that the embodiments and modifications described below may be selectively combined as appropriate.

[0014] [Embodiment] A power storage device according to an embodiment of the present disclosure will be described with reference to FIGS.

[0015] FIG. 1 is a side view schematically illustrating a vehicle equipped with a power storage device according to an embodiment of the present disclosure. The power storage device 100 according to the embodiment of the present disclosure is a power storage device that stores electric power for driving, and is mounted on a vehicle 300. The vehicle 300 runs using the electric power stored in the power storage device 100. Examples of the vehicle 300 include a hybrid vehicle, a plug-in hybrid vehicle, a fuel cell vehicle, and an electric vehicle. The power storage device 100 is disposed below a floor panel of the vehicle 300.

[0016] The vehicle 300 further includes a cooling device 200. The cooling device 200 cools the power storage modules 10 in the power storage device 100. The cooling device 200 is disposed below the power storage device 100.

[0017] The power storage device 100 includes a case 90 and a power storage module 10. The case 90 includes a lower case 91 and an upper case 92. The power storage module 10 is mounted on the lower case 91. More specifically, the power storage module 10 is stored in a space formed by the lower case 91 and the upper case 92.

[0018] Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. The energy storage module 10 includes a plurality of energy storage cells 1 and end plates 11 and 12. The plurality of energy storage cells 1 are arranged and stacked between the end plates 11 and 12. In this embodiment, the number of energy storage cells 1 is two or more, but the number of energy storage cells 1 may be one or more.

[0019] The multiple energy storage cells 1 are sandwiched between end plates 11, 12 in a stacked state, and a predetermined restraining load is applied by a restraining band or the like (not shown). In the present disclosure, the first direction refers to the stacking direction of the multiple energy storage cells 1. In the present disclosure, the second direction refers to a direction perpendicular to the first direction and along the bottom surface 95 of the energy storage device 100. In the present disclosure, the third direction refers to a direction perpendicular to the bottom surface 95 of the energy storage device 100.

[0020] When a plurality of energy storage cells 1 stacked in a first direction are referred to as an energy storage stack, one or more energy storage stacks are arranged side by side in a second direction. When a plurality of energy storage stacks are arranged side by side in the second direction, the end plates 11, 12 may be shared by the plurality of energy storage stacks, or an end plate may be formed for each energy storage stack.

[0021] The side surfaces of the energy storage module 10 include a first side surface 11a and a second side surface 12a arranged in a first direction. More specifically, the first side surface 11a is the side surface (outer side surface) of the two side surfaces of the end plate 11 arranged in the first direction that does not face the energy storage cells 1. The second side surface 12a is the side surface (outer side surface) of the two side surfaces of the end plate 12 arranged in the first direction that does not face the energy storage cells 1.

[0022] A thermally conductive agent 80 is applied between the power storage module 10 and the lower case 91. More specifically, the thermally conductive agent 80 is applied between the plurality of power storage cells 1 and the lower case 91.

[0023] The lower case 91 includes a lower case main body 915 and pedestals 911 and 912. The lower case main body 915 includes a bottom wall 913 and a peripheral wall 914. The peripheral wall 914 stands upright from the peripheral edge of the bottom wall 913. The peripheral wall 914 is formed in a generally rectangular tubular shape. The pedestals 911 and 912 protrude from the bottom wall 913 in the third direction. The pedestals 911 and 912 are formed to extend in the second direction. More specifically, the pedestal 911 has an upper surface 911a and a lower surface aligned in the third direction, two side surfaces aligned in the first direction, and two side surfaces aligned in the second direction. The pedestal 912 has an upper surface 912a and a lower surface aligned in the third direction, two side surfaces aligned in the first direction, and two side surfaces aligned in the second direction. The length of each of the bases 911 and 912 in the second direction may be the same as or different from the length of the power storage module 10 in the second direction.

[0024] The energy storage device 100 further includes brackets 21 and 22 that secure the energy storage module 10 to the lower case 91. The brackets 21 and 22 have the same configuration. That is, in the energy storage device 100, only one type of bracket is required to secure the energy storage module 10 to the lower case 91.

[0025] The brackets 21 and 22 shown in Fig. 2 will be described with reference to Figs. 3 to 6. Fig. 3 is a diagram showing the brackets in this embodiment. Fig. 4 is a diagram showing the power storage module 10 and the bracket 21 fixed to a base 911. Fig. 5 is a diagram showing the power storage module 10 and the bracket 22 fixed to a base 912. Fig. 6 is a plan view schematically showing the power storage module 10 and the brackets 21 and 22.

[0026] 3, the bracket 20 is employed as each of the brackets 21 and 22 (see FIG. 2). As shown in FIG. 3, the bracket 20 includes a first fixing portion 201 and a second fixing portion 202.

[0027] The first fixing portion 201 has a plurality of holes 213 formed therein, into which fastening members 41 (see FIGS. 4 and 5) are inserted. The fastening members 41 are, for example, bolts. With reference to FIGS. 4 and 5, the first fixing portion 201 is fixed to a side surface of the energy storage module 10 by the fastening members 41. More specifically, as shown in FIG. 4, the first fixing portion 201 of the bracket 21 is fixed to the first side surface 11a by the fastening members 41. As shown in FIG. 5, the first fixing portion 201 of the bracket 22 is fixed to the second side surface 12a by the fastening members 41.

[0028] The second fixing portion 202 extends from the first fixing portion 201 in a direction away from the energy storage module 10 and is fixed to the lower case 91 (see FIG. 2). More specifically, the second fixing portion 202 has a plurality of recesses formed therein. The plurality of recesses formed in the second fixing portion 202 include two first recesses 221 and at least one second recess 222. In this embodiment, the plurality of recesses formed in the second fixing portion 202 include two first recesses 221 and three second recesses 222. The number of second recesses 222 may be one or more. Each of the plurality of recesses formed in the second fixing portion 202 has a hole 223 (see FIG. 3) formed therein, into which a fastening member 42 is inserted. The fastening member 42 is, for example, a bolt.

[0029] The second fixing portion 202 is fixed to the lower case 91 (see FIG. 2) by the fastening member 42. More specifically, as shown in FIG. 4, the second fixing portion 202 of the bracket 21 extends from the first fixing portion 201 in the direction opposite to the first direction, and is fixed to the upper surface 911a of the base 911 by the fastening member 42. On the other hand, as shown in FIG. 5, the second fixing portion 202 of the bracket 22 extends from the first fixing portion 201 in the first direction, and is fixed to the upper surface 912a of the base 912 by the fastening member 42.

[0030] The rigidity of each first recess 221 in the third direction is a first rigidity. On the other hand, the rigidity of each second recess 222 in the third direction is a second rigidity. The second rigidity is lower than the first rigidity. More specifically, a reinforcing portion 55 is formed in each first recess 221 to increase the rigidity of the first recess 221 in the third direction. On the other hand, no reinforcing portion 55 is formed in each second recess 222. By forming the reinforcing portion 55 in the first recess 221 and not forming the reinforcing portion 55 in the second recess 222, the rigidity in the third direction of the first recess 221 and the second recess 222 is made different. More specifically, by forming the reinforcing portion 55 in the first recess 221 and not forming the reinforcing portion 55 in the second recess 222, the rigidity of the first recess 221 in the third direction is made higher than the rigidity of the second recess 222 in the third direction.

[0031] The depth of the second recess 222 is shallower than the depth of the first recess 221. The depth of the second recess 222 may be the same as the depth of the first recess 221. In this disclosure, "having the same depth" includes cases where the depths are completely the same and cases where the depths are substantially the same. In this disclosure, "substantially the same" means that some error due to manufacturing variations and the like is included.

[0032] The thickness of the portion 228 of the bracket that defines the second recess 222 is the same as the thickness of the portion 227 that defines the first recess 221. In this disclosure, "the same thickness" includes cases where the thicknesses are completely the same and cases where the thicknesses are substantially the same. In this disclosure, "substantially the same" means that some degree of error due to manufacturing variations and the like is included.

[0033] 6, the two first recesses 221 in each of the brackets 21, 22 are disposed at positions symmetrical with respect to an imaginary line 75 that passes through the center of gravity position 70 of the power storage module 10 and extends in the first direction. More specifically, when the power storage module 10 and the bracket 21 are viewed from a position above and away from the power storage module 10 and the bracket 21, the two first recesses 221 in the bracket 21 are disposed at positions symmetrical with respect to the imaginary line 75. Furthermore, when the power storage module 10 and the bracket 22 are viewed from a position above and away from the power storage module 10 and the bracket 22, the two first recesses 221 in the bracket 22 are disposed at positions symmetrical with respect to the imaginary line 75. The upward direction is the third direction.

[0034] 4 and 5 again, as described above, the first fixing portion 201 is fixed to the side surface of the energy storage module 10. The second fixing portion 202 is fixed to the lower case 91 (see FIG. 2). By fixing the first fixing portion 201 to the side surface of the energy storage module 10 and fixing the second fixing portion 202 to the lower case 91, the energy storage module 10 and the lower case 91 are fixed together.

[0035] The lower case 91 may include a lower case main body 915 (see FIG. 2) but not include the pedestals 911, 912. When the lower case 91 includes the lower case main body 915 but does not include the pedestals 911, 912, the second fixing portion 202 is fixed to the bottom wall 913 (see FIG. 2) by the fastening member 42.

[0036] As described above, in the energy storage device 100 of this embodiment, the bracket 20 for fixing the energy storage module 10 to the lower case 91 includes two first recesses 221 and at least one second recess 222. Furthermore, in the energy storage device 100 of this embodiment, the rigidity of the first recess 221 in the third direction is higher than the rigidity of the second recess 222 in the third direction. Therefore, the assembly height and assembly angle of the energy storage module 10 when fixed to the lower case 91 are determined by the two first recesses 221 of the multiple recesses. Even if the second recess 222 comes into contact with the lower case 91 when the energy storage module 10 is fixed to the lower case 91, the second recess 222 is deformed by the weight of the energy storage module 10, and therefore the assembly height and assembly angle of the energy storage module 10 are determined by the two first recesses 221 of the multiple recesses.

[0037] Generally, when a power storage module is fixed to a lower case using a bracket, it is difficult to control the assembly height and assembly angle of the power storage module due to the large number of fastening points. If the power storage module and the lower case are fixed while the power storage module is tilted relative to the lower case, the thickness of the thermally conductive agent between the power storage module and the lower case varies. Variations in the thickness of the thermally conductive agent deteriorate the cooling performance of the cooling device for the power storage cells. In contrast, with the power storage device 100 of this embodiment, the assembly height and assembly angle of the power storage module 10 when fixed to the lower case 91 are determined by the two first recesses 221 among the multiple recesses. This prevents the power storage module 10 from tilting relative to the lower case 91, thereby suppressing variations in the thickness of the thermally conductive agent 80 between the power storage module 10 and the lower case 91. Therefore, with the power storage device 100 of this embodiment, the cooling performance of the cooling device 200 for the power storage cells 1 is improved.

[0038] Furthermore, in the energy storage device 100 of this embodiment, the energy storage module 10 and the lower case 91 are fixed together by a plurality of fastening members 41, 42. Therefore, according to the energy storage device 100 of this embodiment, it is possible to ensure the fastening force required to fix the energy storage module 10 and the lower case 91 together.

[0039] Furthermore, in the energy storage device 100 of this embodiment, of the multiple recesses, only the two first recesses 221 require strict height control. That is, in the energy storage device 100 of this embodiment, it is only necessary to suppress manufacturing variations in the depth of only the two first recesses 221 out of the depths of the multiple recesses. This makes it possible to reduce management costs in the manufacturing process of the bracket 20. Therefore, according to the energy storage device 100 of this embodiment, the product cost of the energy storage device 100 can be reduced.

[0040] Furthermore, the battery pack disclosed in JP 2016-212980 A (Patent Document 1) requires many types of heat transfer plates. In contrast, the energy storage device 100 of this embodiment requires only one type of bracket to fasten the energy storage module 10 and the lower case 91. Therefore, according to the energy storage device 100 of this embodiment, the number of types of parts required for the energy storage device 100 can be reduced.

[0041] Furthermore, in the battery pack disclosed in JP 2016-212980 A (Patent Document 1), there is a risk of abnormal noise being generated due to contact of the heat transfer plate with the housing. In contrast, in the energy storage device 100 of this embodiment, a thermal conductive agent 80 is applied between the energy storage module 10 and the lower case 91, thereby suppressing the generation of abnormal noise.

[0042] [Variation 1] In the first modification, a modification of the bracket that fixes the power storage module 10 and the lower case 91 will be described.

[0043] In the above embodiment, by forming the reinforcing portion 55 in the first recess 221, the rigidity of the first recess 221 in the third direction is made higher than the rigidity of the second recess 222 in the third direction. In contrast, in Modification 1, by providing a notch in the second recess to reduce the rigidity of the second recess in the third direction, the rigidity of the first recess in the third direction is made higher than the rigidity of the second recess in the third direction.

[0044] Fig. 7 is a diagram showing a bracket according to Modification 1. Bracket 20A according to Modification 1 may be employed as each of brackets 21 and 22 (see Fig. 2). Bracket 20A according to Modification 1 includes a first fixing portion 201 and a second fixing portion 202A. Fig. 7 shows a state in which bracket 20A according to Modification 1 is fixed to first side surface 11a.

[0045] As described above, the first fixing portion 201 is fixed to the side surface of the energy storage module 10 by the fastening member 41. More specifically, when the bracket 20A according to the first modification is fixed to the first side surface 11a, as shown in Fig. 7, the first fixing portion 201 of the bracket 20A is fixed to the first side surface 11a by the fastening member 41. When the bracket 20A according to the first modification is fixed to the second side surface 12a (see Fig. 5), the first fixing portion 201 of the bracket 20A is fixed to the second side surface 12a by the fastening member 41.

[0046] The second fixing portion 202A extends from the first fixing portion 201 in a direction away from the energy storage module 10, and is fixed to the lower case 91 (see FIG. 2). More specifically, the second fixing portion 202A has a plurality of recesses formed therein. The plurality of recesses formed in the second fixing portion 202A include two first recesses 221A and at least one second recess 222A. In the first modification, the plurality of recesses formed in the second fixing portion 202A include two first recesses 221A and three second recesses 222A. The number of second recesses 222A may be one or more. Each of the plurality of recesses formed in the second fixing portion 202A has a hole 223 (see FIG. 3) formed therein, into which the fastening member 42 is inserted.

[0047] The second fixing portion 202A is fixed to the lower case 91 (see FIG. 2) by the fastening member 42. More specifically, when the bracket 20A according to the first modification is fixed to the first side surface 11a, as shown in FIG. 7, the second fixing portion 202A extends from the first fixing portion 201 in the direction opposite to the first direction and is fixed to the upper surface 911a of the base 911 by the fastening member 42. When the bracket 20A according to the first modification is fixed to the second side surface 12a (see FIG. 5), the second fixing portion 202A extends from the first fixing portion 201 in the first direction and is fixed to the upper surface 912a (see FIG. 5) of the base 912 (see FIG. 5) by the fastening member 42.

[0048] The rigidity of each first recess 221A in the third direction is a first rigidity. On the other hand, the rigidity of each second recess 222A in the third direction is a second rigidity. The second rigidity is lower than the first rigidity. More specifically, each second recess 222A is provided with a notch 65 that reduces the rigidity of the second recess 222A in the third direction. On the other hand, each first recess 221A is not provided with a notch 65. By providing the notch 65 in the second recess 222A and not providing the notch 65 in the first recess 221A, the rigidity in the third direction of the first recess 221A and the second recess 222A is made different. More specifically, by providing the notch 65 in the second recess 222A and not providing the notch 65 in the first recess 221A, the rigidity in the third direction of the first recess 221A is made higher than the rigidity in the third direction of the second recess 222A.

[0049] The depth of the second recess 222A is shallower than the depth of the first recess 221 A. Note that the depth of the second recess 222A may be the same as the depth of the first recess 221A.

[0050] In bracket 20A, the thickness of portion 228A that defines second recess 222A is the same as the thickness of portion 227A that defines first recess 221A.

[0051] The two first recesses 221A are disposed at positions symmetrical with respect to an imaginary line 75 (see FIG. 6) that passes through the center of gravity 70 (see FIG. 6) of the power storage module 10 and extends in the first direction. More specifically, when the power storage module 10 and the bracket 20A are viewed from a position above and away from the power storage module 10 and the bracket 20A, the two first recesses 221A of the bracket 20A are disposed at positions symmetrical with respect to the imaginary line 75. The upward direction is the third direction.

[0052] As described above, the first fixing part 201 is fixed to the side surface of the energy storage module 10. The second fixing part 202A is fixed to the lower case 91 (see FIG. 2). By fixing the first fixing part 201 to the side surface of the energy storage module 10 and fixing the second fixing part 202A to the lower case 91, the energy storage module 10 and the lower case 91 are fixed together.

[0053] Thus, in the first modification, the rigidity of the first recess 221A in the third direction is higher than the rigidity of the second recess 222A in the third direction. Therefore, the assembly height and assembly angle of the energy storage module 10 when the energy storage module 10 is fixed to the lower case 91 are determined by the two first recesses 221A out of the multiple recesses. This prevents the energy storage module 10 from tilting relative to the lower case 91, thereby preventing variations in the thickness of the thermal conductive agent 80 located between the energy storage module 10 and the lower case 91. Therefore, according to the first modification, the cooling performance of the energy storage cells 1 by the cooling device 200 is improved.

[0054] Furthermore, according to the first modification, in addition to improving the cooling performance, the same effects as those described in the above embodiment are achieved.

[0055] Furthermore, in the first modification, instead of forming a reinforcing portion 55 (see FIG. 3 ) in the first recess 221A, a notch 65 is provided in the second recess 222A, so that the rigidity of the first recess 221A in the third direction is higher than the rigidity of the second recess 222A in the third direction. Therefore, according to the first modification, the weight of the bracket that fixes the power storage module 10 and the lower case 91 can be made lighter than in the above embodiment. Therefore, if a sufficient fastening force required to fix the power storage module 10 and the lower case 91 can be ensured, the weight of the power storage device 100 can be made lighter than in the above embodiment by fixing the power storage module 10 and the lower case 91 using the bracket 20A according to the first modification.

[0056] [Variation 2] In Modification 2, another modification of the bracket that fixes the power storage module 10 and the lower case 91 will be described.

[0057] In the above embodiment, by forming reinforcing portion 55 in first recess 221, the rigidity in the third direction of first recess 221 is made higher than the rigidity in the third direction of second recess 222. In contrast, in Modification 2, the thickness of the portion defining the second recess is made thinner than the thickness of the portion defining the first recess, so that the rigidity in the third direction of the first recess is made higher than the rigidity in the third direction of the second recess.

[0058] Fig. 8 is a diagram showing a bracket according to Modification 2. Bracket 20B according to Modification 2 may be employed as each of brackets 21 and 22 (see Fig. 2). Bracket 20B according to Modification 2 includes a first fixing portion 201 and a second fixing portion 202B. Fig. 8 shows a state in which bracket 20B according to Modification 2 is fixed to first side surface 11a.

[0059] As described above, the first fixing portion 201 is fixed to the side surface of the energy storage module 10 by the fastening member 41. More specifically, when the bracket 20B according to the second modification is fixed to the first side surface 11a, as shown in FIG. 8, the first fixing portion 201 of the bracket 20B is fixed to the first side surface 11a by the fastening member 41. When the bracket 20B according to the second modification is fixed to the second side surface 12a (see FIG. 5), the first fixing portion 201 of the bracket 20B is fixed to the second side surface 12a by the fastening member 41.

[0060] The second fixing portion 202B extends from the first fixing portion 201 in a direction away from the energy storage module 10 and is fixed to the lower case 91 (see FIG. 2). More specifically, a plurality of recesses are formed in the second fixing portion 202B. The plurality of recesses formed in the second fixing portion 202B include two first recesses 221B and at least one second recess 222B. In the second modification example, the plurality of recesses formed in the second fixing portion 202B include two first recesses 221B and three second recesses 222B. The number of second recesses 222B may be one or more. Each of the plurality of recesses formed in the second fixing portion 202B is formed with a hole 223 (see FIG. 3) into which the fastening member 42 is inserted.

[0061] The second fixing portion 202B is fixed to the lower case 91 (see FIG. 2) by the fastening member 42. More specifically, when the bracket 20B according to the second modification is fixed to the first side surface 11a, the second fixing portion 202B extends from the first fixing portion 201 in the direction opposite to the first direction and is fixed to the upper surface 911a of the base 911 by the fastening member 42. When the bracket 20B according to the second modification is fixed to the second side surface 12a (see FIG. 5), the second fixing portion 202B extends from the first fixing portion 201 in the first direction and is fixed to the upper surface 912a (see FIG. 5) of the base 912 (see FIG. 5) by the fastening member 42.

[0062] The rigidity of each first recess 221B in the third direction is a first rigidity. On the other hand, the rigidity of each second recess 222B in the third direction is a second rigidity. The second rigidity is lower than the first rigidity. More specifically, the thickness of portion 228B defining second recess 222B is thinner than the thickness of portion 227B defining first recess 221B. By making the thickness of portion 228B defining second recess 222B thinner than the thickness of portion 227B defining first recess 221B, the rigidity in the third direction is made different between first recess 221B and second recess 222B. More specifically, by making the thickness of portion 228B defining second recess 222B thinner than the thickness of portion 227B defining first recess 221B, the rigidity of first recess 221B in the third direction is made higher than the rigidity of second recess 222B in the third direction.

[0063] The depth of the second recess 222B is shallower than the depth of the first recess 221 B. Note that the depth of the second recess 222B may be the same as the depth of the first recess 221B.

[0064] The two first recesses 221B are disposed at positions symmetrical with respect to an imaginary line 75 (see FIG. 6) that passes through the center of gravity 70 (see FIG. 6) of the power storage module 10 and extends in the first direction. More specifically, when the power storage module 10 and the bracket 20B are viewed from a position above and away from the power storage module 10 and the bracket 20B, the two first recesses 221B of the bracket 20B are disposed at positions symmetrical with respect to the imaginary line 75. The upward direction is the third direction.

[0065] As described above, the first fixing portion 201 is fixed to the side surface of the energy storage module 10. The second fixing portion 202B is fixed to the lower case 91 (see FIG. 2). By fixing the first fixing portion 201 to the side surface of the energy storage module 10 and fixing the second fixing portion 202B to the lower case 91, the energy storage module 10 and the lower case 91 are fixed together.

[0066] Thus, in the second modification, the rigidity of the first recess 221B in the third direction is higher than the rigidity of the second recess 222B in the third direction. Therefore, the assembly height and assembly angle of the energy storage module 10 when the energy storage module 10 is fixed to the lower case 91 are determined by the two first recesses 221B of the multiple recesses. This prevents the energy storage module 10 from tilting relative to the lower case 91, thereby preventing variations in the thickness of the thermal conductive agent 80 located between the energy storage module 10 and the lower case 91. Therefore, according to the second modification, the cooling performance of the energy storage cells 1 by the cooling device 200 is improved.

[0067] Furthermore, according to the second modification, in addition to improving the cooling performance, the same effects as those described in the above embodiment are achieved.

[0068] Furthermore, in Modification 2, instead of forming reinforcing portion 55 (see FIG. 3 ) in first recess 221B, portion 228B defining second recess 222B is made thinner than portion 227B defining first recess 221B, so that the rigidity of first recess 221B in the third direction is greater than the rigidity of second recess 222B in the third direction. Therefore, according to Modification 2, the weight of the bracket that fixes power storage module 10 and lower case 91 can be made lighter than in the above embodiment. Therefore, if a sufficient fastening force required to fix power storage module 10 and lower case 91 can be ensured, fixing power storage module 10 and lower case 91 using bracket 20B according to Modification 2 can make the weight of power storage device 100 lighter than in the above embodiment.

[0069] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0070] 1 Energy storage cell, 10 Energy storage module, 11, 12 End plate, 11a First side surface, 12a Second side surface, 20, 20A, 20B, 21, 22 Bracket, 41, 42 Fastening member, 55 Reinforcement portion, 65 Notch, 70 Center of gravity position, 75 Virtual line, 80 Thermal conductive material, 90 Case, 91 Lower case, 92 Upper case, 95 Bottom surface, 100 Energy storage device, 200 Cooling device, 201 First fixing portion, 202, 202A, 202B Second fixing portion, 213, 223 Hole, 221, 221A, 221B First recess, 222, 222A, 222B Second recess, 227, 227A, 227B, 228, 228A, 228B Part, 300 Vehicle, 911, 912 base, 911a, 912a top surface, 913 bottom wall, 914 peripheral wall, 915 lower case body.

Claims

1. a power storage module; a lower case in which the power storage module is mounted; a bracket that fixes the power storage module and the lower case, The bracket is a first fixing portion fixed to a side surface of the power storage module; a second fixing portion extending from the first fixing portion in a direction away from the power storage module and fixed to the lower case, The second fixing portion has a plurality of recesses formed therein, Each of the plurality of recesses has a hole formed therein into which a fastening member is inserted, The plurality of recesses include two first recesses having a first rigidity and at least one second recess having a second rigidity lower than the first rigidity.

2. The power storage device according to claim 1 , wherein reinforcing portions are formed in the two first recesses.

3. The power storage device according to claim 1 , wherein the at least one second recessed portion is provided with a notch.

4. The power storage device according to claim 1 , wherein a thickness of a portion of the bracket that defines the at least one second recess is thinner than a thickness of a portion that defines the two first recesses.

5. the side surfaces of the energy storage module include a first side surface and a second side surface arranged in a first direction; When the power storage module and the bracket are viewed from a position above and spaced apart from the power storage module and the bracket, The energy storage device according to any one of claims 1 to 4, wherein the two first recesses are arranged at positions symmetrical with respect to an imaginary line that passes through a center of gravity of the energy storage module and extends in the first direction.

Images