Power storage device

Abstract

To provide a power storage device capable of suppressing occurrence of a difference in temperature between modules.SOLUTION: The power storage device 100 includes a power storage module 10, a case 40 in which the power storage module 10 is disposed, and a fixing bracket 50 that fixes the power storage module 10 to the case 40. A power storage module 10 includes an upper stage module 20 and a lower stage module 30 stacked in a vertical direction. The upper module 20 has an upper surface 22 and a lower surface 23 arranged in the vertical direction. Lower module 30 has an upper surface 32 and a lower surface 33 arranged in the up-down direction. The lower surface 23 and the upper surface 32 face each other in the up-down direction. The lower surface 33 is in contact with the case 40. A contact area between the fixing bracket 50 and the upper stage module 20 is larger than a contact area between the fixing bracket 50 and the lower stage module 30.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Japanese Patent Application Laid-Open Publication No. 2014-222591 (Patent Document 1) discloses a battery pack including a plurality of battery modules, each of which has a plurality of prismatic batteries arranged side by side. The plurality of battery modules are arranged in one direction. The battery pack is housed in a case. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-222591 Summary of the Invention [Problem to be solved by the invention]

[0004] Although not explicitly stated in Patent Document 1, there are cases where one battery module at one end of the multiple battery modules is in contact with the case. In this case, heat is released from the battery module at the end to the case, which is thought to result in a relatively high cooling efficiency for the battery module at the end compared to the other battery modules.

[0005] The present disclosure has been made to solve the above-mentioned problems, and has an object to provide an electricity storage device that can suppress the occurrence of differences in temperature among modules. [Means for solving the problem]

[0006] An energy storage device according to one aspect of the present disclosure includes an energy storage module, an arrangement member on which the energy storage module is arranged, and a fixing bracket that fixes the energy storage module to the arrangement member. The energy storage module includes a first module and a second module stacked in a stacking direction. The first module has a first surface and a second surface that are arranged in the stacking direction. The second module has a third surface and a fourth surface that are arranged in the stacking direction. The second surface and the third surface face each other in the stacking direction. The fourth surface is in contact with the arrangement member. The contact area between the fixing bracket and the first module is larger than the contact area between the fixing bracket and the second module.

[0007] In the energy storage device according to one aspect of the present disclosure, as described above, the fourth surface is in contact with the arrangement member, and the contact area between the fixing bracket and the first module is larger than the contact area between the fixing bracket and the second module. This allows the amount of heat dissipated from the second module to the arrangement member to be relatively large because the fourth surface is in contact with the arrangement member, while the contact area between the fixing bracket and the first module is larger than the contact area between the fixing bracket and the second module, allowing the amount of heat dissipated from the first module to the fixing bracket to be larger than the amount of heat dissipated from the second module to the fixing bracket. As a result, it is possible to suppress a difference in temperature between the first module and the second module.

[0008] The first module may include a first energy storage cell, and the second module may include a second energy storage cell. The first surface may be in contact with the fixing bracket. The first energy storage cell may be disposed at a position closer to the first surface than the center of the first module in the stacking direction. The second energy storage cell may be disposed at a position closer to the fourth surface than the center of the second module in the stacking direction. With this configuration, it is possible to easily increase the amount of heat dissipation from the first energy storage cell to the fixing bracket, and also to easily increase the amount of heat dissipation from the second energy storage cell to the arrangement member.

[0009] The energy storage device may further include a thermally conductive member sandwiched between the first module and the second module. This configuration can improve the efficiency of heat transfer between the first module and the second module. As a result, it is possible to further reduce the difference in temperature between the first module and the second module.

[0010] Each of the second surface and the third surface may have projections and recesses. The projections and recesses on the second surface may have a first projection and a first recess. The projections and recesses on the third surface may have a second projection and a second recess. The first projection may be fitted into the second recess. The second projection may be fitted into the first recess. With this configuration, the first projection and the second recess are fitted together, and the second projection and the first recess are fitted together, so that the contact area between the second surface and the third surface can be easily increased. As a result, the efficiency of heat transfer between the first module and the second module can be further improved. As a result, the occurrence of a difference in temperature between the first module and the second module can be further suppressed.

[0011] The contact area between the second module and the fixing bracket may be zero. This configuration can suppress heat dissipation from the second module to the fixing bracket. As a result, it is possible to easily suppress the temperature difference between the first module and the second module. [Effects of the Invention]

[0012] According to the present disclosure, it is possible to suppress the occurrence of differences in temperature among modules. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a diagram showing the configuration of a vehicle equipped with a power storage device according to a first embodiment. [Figure 2] 1 is a cross-sectional view showing the configuration of an electricity storage device according to a first embodiment. [Figure 3] FIG. 5 is a cross-sectional view showing the configuration of an electricity storage device according to a second embodiment. [Figure 4] FIG. 10 is a plan view of the lower surface of the upper module of the energy storage device according to the second embodiment, viewed from below. [Figure 5] FIG. 11 is a plan view of the upper surface of the lower module of the energy storage device according to the second embodiment, viewed from above. [Figure 6] FIG. 4 is a cross-sectional view showing the configuration of an electricity storage device according to a modified example of the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0015] 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.

[0016] [First embodiment] An energy storage device 100 according to the first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a side view that schematically shows a vehicle 1 including the energy storage device 100 according to the first embodiment. In this specification, the X direction, Y direction, and Z direction are directions that are perpendicular to one another. For example, the X direction and Y direction are the front-rear direction and the vehicle width direction of the vehicle 1 when the energy storage device 100 is mounted on the vehicle 1, respectively. The Z direction is the up-down (vertical) direction. The Z direction is an example of the "stacking direction" in the present disclosure.

[0017] Referring to Fig. 1, power storage device 100 is a device for storing electric power for driving vehicle 1, for example. Power storage device 100 is disposed at the bottom of vehicle 1. Vehicle 1 is, for example, an industrial vehicle (for example, a forklift or a power shovel). Note that the use of power storage device 100 is not limited to vehicles, and it may also be used for other purposes (for example, as a stationary power storage device).

[0018] 2 is a partially enlarged cross-sectional view showing the configuration of the energy storage device 100. The energy storage device 100 includes an energy storage module 10, a case 40, a fixing bracket 50, bolts 60 and 61, and a thermally conductive material 70. The case 40 and the thermally conductive material 70 are examples of the "positioning member" and the "thermally conductive member" of the present disclosure, respectively.

[0019] The power storage module 10 is disposed (mounted, housed) in a case 40. A space S for housing the power storage module 10 is formed inside the case 40. The case 40 is made of metal (for example, iron).

[0020] The energy storage module 10 includes an upper module 20 and a lower module 30. The upper module 20 and the lower module 30 are stacked (arranged) in the Z direction. The upper module 20 is disposed on the Z1 side of the lower module 30. The upper module 20 and the lower module 30 are examples of the "first module" and "second module" of the present disclosure, respectively.

[0021] The upper module 20 includes a module case 20a and a plurality of storage cells 21. The plurality of storage cells 21 are housed in the module case 20a. The lower module 30 includes a module case 30a and a plurality of storage cells 31. The plurality of storage cells 31 are housed in the module case 30a. The module case 20a and the module case 30a have the same shape and size. The storage cells 21 and the storage cells 31 are examples of the "first storage cell" and the "second storage cell" of the present disclosure, respectively.

[0022] The plurality of storage cells 21 and the plurality of storage cells 31 are arranged in the X direction. The arrangement direction of the storage cells 21 (31) is not limited to the above example. The plurality of storage cells 21 and the plurality of storage cells 31 may be arranged in the Y direction or the Z direction. The storage cells 21 and the storage cells 31 have the same configuration.

[0023] Upper module 20 has an upper surface 22, a lower surface 23, a side surface 24, and a side surface 25. Upper surface 22 and lower surface 23 are arranged in the Z direction. Upper surface 22 is disposed on the Z1 side of lower surface 23. Upper surface 22 may be the upper end surface of upper module 20. Lower surface 23 may be the lower end surface (bottom surface) of upper module 20. Each of upper surface 22, lower surface 23, side surface 24, and side surface 25 is a surface of module case 20a. Each of upper surface 22, lower surface 23, side surface 24, and side surface 25 is a flat surface. Upper surface 22 and lower surface 23 are examples of the "first surface" and "second surface" of the present disclosure, respectively.

[0024] Side surface 24 and side surface 25 are arranged in the X direction. Side surface 24 is disposed on the X1 side of side surface 25. Side surface 24 may be the end surface of upper module 20 on the X1 side. Side surface 25 may be the end surface of upper module 20 on the X2 side.

[0025] The lower module 30 has an upper surface 32, a lower surface 33, a side surface 34, and a side surface 35. The upper surface 32 and the lower surface 33 are arranged in the Z direction. The upper surface 32 is disposed on the Z1 side of the lower surface 33. The upper surface 32 may be the upper end surface of the lower module 30. The lower surface 33 may be the lower end surface (bottom surface) of the lower module 30. Each of the upper surface 32, the lower surface 33, the side surface 34, and the side surface 35 is a surface of the module case 30a. Each of the upper surface 32, the lower surface 33, the side surface 34, and the side surface 35 is a flat surface. The upper surface 32 and the lower surface 33 are examples of the "third surface" and the "fourth surface" of the present disclosure, respectively.

[0026] The side surface 34 and the side surface 35 are arranged in the X direction. The side surface 34 is disposed on the X1 side of the side surface 35. The side surface 34 may be the end surface of the lower module 30 on the X1 side. The side surface 35 may be the end surface of the lower module 30 on the X2 side.

[0027] The lower surface 23 of the upper module 20 and the upper surface 32 of the lower module 30 face each other in the Z direction.

[0028] The upper surface 22 of the upper module 20, the lower surface 23 of the upper module 20, the upper surface 32 of the lower module 30, and the lower surface 33 of the lower module 30 have the same area. The side surface 24 of the upper module 20, the side surface 25 of the upper module 20, the side surface 34 of the lower module 30, and the side surface 35 of the lower module 30 have the same area. The area of ​​the upper surface 22 (lower surface 23, upper surface 32, lower surface 33) may be, for example, twice or more the area of ​​the side surface 24 (side surface 25, side surface 34, side surface 35). The relationship between the areas of the surfaces need not be limited to the above example.

[0029] The case 40 includes a bottom plate 41 and side walls 42. The bottom plate 41 extends on the XY plane so as to be perpendicular to the Z direction. The bottom plate 41 covers the energy storage module 10 from the Z2 side. The bottom plate 41 supports the energy storage module 10 from the Z2 side.

[0030] The sidewall 42 extends on the YZ plane so as to be perpendicular to the X direction. That is, the sidewall 42 is perpendicular to the bottom plate 41. The sidewall 42 extends from an end 41a of the bottom plate 41 on the X1 side to the Z1 side. The sidewall 42 is disposed on the X1 side of the energy storage module 10. The sidewall 42 restricts movement of the energy storage module 10 toward the X1 side. The sidewall 42 may be welded to the end 41a of the bottom plate 41, for example. Alternatively, the sidewall 42 may be formed integrally with the bottom plate 41.

[0031] The bottom plate 41 is in contact with the lower surface 33 of the lower module 30. The side walls 42 are in contact with the side surfaces 24 of the upper module 20 and the side surfaces 34 of the lower module 30.

[0032] The case 40 has a thickness t1. Although only the thickness t1 of the bottom plate 41 in the Z direction is shown in Fig. 2, the thickness of the side wall 42 in the X direction may also be equal to the thickness t1.

[0033] The fixing bracket 50 fixes the energy storage module 10 to the case 40. The fixing bracket 50 includes a first bracket 51 and a second bracket 52. The first bracket 51 is fastened to the bottom plate 41 of the case 40 by a bolt 60. The second bracket 52 is fastened to the side wall 42 of the case 40 by a bolt 61. The fixing bracket 50 is made of metal (for example, iron). The first bracket 51 and the second bracket 52 may be connected to the case 40 by, for example, welding.

[0034] Specifically, the first bracket 51 has a horizontal portion 51a and a vertical portion 51b. The horizontal portion 51a extends along the bottom plate 41 of the case 40. That is, the horizontal portion 51a extends on the XY plane so as to be perpendicular to the Z direction. The horizontal portion 51a is in contact with the bottom plate 41. The bolt 60 fastens the bottom plate 41 and the horizontal portion 51a. Note that the bolt 60 does not penetrate the bottom plate 41. This makes it possible to prevent water from entering the case 40 through the fastening portion formed by the bolt 60.

[0035] The vertical portion 51b extends on the YZ plane perpendicular to the X direction. The vertical portion 51b extends from the X1-side end (not numbered) of the horizontal portion 51a toward the Z1 side. The vertical portion 51b contacts each of the side surface 25 of the upper module 20 and the side surface 35 of the lower module 30. This applies a pressing force from the vertical portion 51b to the X1 side against the upper module 20 and the lower module 30. As a result, movement of each of the upper module 20 and the lower module 30 toward the X2 side is restricted.

[0036] The vertical portion 51b is formed integrally with the horizontal portion 51a. That is, the first bracket 51 is a single L-shaped member. The vertical portion 51b may be separate from the horizontal portion 51a. In this case, the vertical portion 51b may be connected to the horizontal portion 51a by welding or the like.

[0037] The second bracket 52 has a horizontal portion 52a and a vertical portion 52b. The horizontal portion 52a extends on the XY plane along the top surface 22 of the upper module 20. The horizontal portion 52a is in contact with the top surface 22. This applies a pressing force from the horizontal portion 52a to the upper module 20 and the lower module 30 in the Z2 direction. As a result, the upper module 20 and the lower module 30 are prevented from moving in the Z1 direction (for example, from bouncing upward due to vibration).

[0038] The vertical portion 52b extends on the YZ plane perpendicular to the X direction. The vertical portion 52b extends from the end (not numbered) of the horizontal portion 52a on the X1 side toward the Z1 side. The vertical portion 52b is in contact with the side wall 42 of the case 40.

[0039] The bolt 61 fastens the side wall 42 to the vertical portion 52b. The bolt 61 does not penetrate the side wall 42. This makes it possible to prevent water from entering the case 40 through the fastening portion of the bolt 61. The direction in which the bolt 61 (shaft) extends is aligned with the traveling direction (X direction) of the vehicle 1 (FIG. 1). This makes it possible to prevent the bolt 61 from being damaged due to acceleration and deceleration forces when the vehicle 1 is traveling.

[0040] The vertical portion 52b is formed integrally with the horizontal portion 52a. That is, the second bracket 52 is a single L-shaped member. The vertical portion 52b may be separate from the horizontal portion 52a. In this case, the vertical portion 52b may be connected to the horizontal portion 52a by welding or the like.

[0041] The fixed bracket 50 has a thickness t2. Although Fig. 2 shows only the thickness t2 in the Z direction of the horizontal portion 52a of the second bracket 52, the thicknesses of other portions of the fixed bracket 50 (the thickness in the Z direction of the horizontal portion 51a, the thickness in the X direction of the vertical portion 51b, and the thickness in the X direction of the vertical portion 51b) may also be equal to the thickness t2.

[0042] The thickness t2 of the fixing bracket 50 is greater than the thickness t1 of the case 40. This makes it possible to increase the amount of heat dissipated from the power storage module 10 to the fixing bracket 50.

[0043] The thermally conductive material 70 is sandwiched between the upper module 20 and the lower module 30. That is, the thermally conductive material 70 is in contact with both the lower surface 23 of the upper module 20 and the upper surface 32 of the lower module 30. The thermally conductive material 70 may be a thermally conductive adhesive. The thermally conductive material 70 may be in contact with the side wall 42 of the case 40 and / or the first bracket 51 (vertical portion 51b).

[0044] Here, in a conventional power storage device, it is considered that the cooling efficiency of the power storage modules that are in contact with the case among the plurality of power storage modules is relatively high compared to the other battery modules.

[0045] In this embodiment, the contact area between the case 40 and the upper module 20 is the area of ​​the side surface 24. The contact area between the case 40 and the lower module 30 is the sum of the area of ​​the bottom surface 33 and the area of ​​the side surface 34. As described above, the area of ​​the side surface 24 and the area of ​​the side surface 34 are equal, so the contact area between the case 40 and the lower module 30 is larger than the contact area between the case 40 and the upper module 20 by the area of ​​the bottom surface 33. Therefore, the amount of heat dissipated from the lower module 30 to the case 40 is larger than the amount of heat dissipated from the upper module 20 to the case 40.

[0046] Therefore, in this embodiment, the contact area between the fixing bracket 50 and the upper module 20 is larger than the contact area between the fixing bracket 50 and the lower module 30 .

[0047] The contact area between the fixing bracket 50 and the upper module 20 is the sum of the area of ​​the top surface 22 and the area of ​​the side surface 25. The contact area between the fixing bracket 50 and the lower module 30 is the area of ​​the side surface 35. As described above, the area of ​​the side surface 25 and the area of ​​the side surface 35 are equal. Therefore, the contact area between the fixing bracket 50 and the upper module 20 is larger than the contact area between the fixing bracket 50 and the lower module 30 by the area of ​​the top surface 22. As a result, the amount of heat dissipated from the upper module 20 to the fixing bracket 50 is larger than the amount of heat dissipated from the lower module 30 to the fixing bracket 50. As a result, the difference between the amount of heat dissipated by the upper module 20 and the amount of heat dissipated by the lower module 30 is suppressed.

[0048] Moreover, each of the plurality of storage cells 21 is disposed at a position closer to the upper surface 22 than the center of the upper module 20 in the Z direction (position P1 in FIG. 2 ). In other words, the distance between each of the plurality of storage cells 21 and the upper surface 22 is shorter than the distance between each of the plurality of storage cells 21 and the lower surface 23. Specifically, each of the plurality of storage cells 21 is in contact with the upper surface 22. Each of the plurality of storage cells 21 is spaced apart from the lower surface 23. Note that the lower end of each storage cell 21 may be located closer to the Z1 side than position P1.

[0049] Furthermore, each of the plurality of storage cells 31 is disposed at a position closer to the lower surface 33 than the center of the lower module 30 in the Z direction (position P2 in FIG. 2 ). In other words, the distance between each of the plurality of storage cells 31 and the lower surface 33 is shorter than the distance between each of the plurality of storage cells 31 and the upper surface 32. Specifically, each of the plurality of storage cells 31 is in contact with the lower surface 33. Each of the plurality of storage cells 31 is spaced apart from the upper surface 32. Note that the upper end of each storage cell 31 may be located closer to the Z2 side than position P2.

[0050] As described above, in the first embodiment, the contact area between the fixing bracket 50 and the upper module 20 is larger than the contact area between the fixing bracket 50 and the lower module 30. This allows a relatively high amount of heat to be dissipated from the upper module 20 to the fixing bracket 50. As a result, it is possible to prevent the temperature of the lower module 30 from becoming excessively lower than the temperature of the upper module 20, which would be caused by a relatively high amount of heat dissipated from the lower module 30 to the case 40.

[0051] [Second embodiment] Next, a power storage device 200 of the present disclosure will be described with reference to Figures 3 to 5. Unlike the first embodiment in which the lower surface 23 of the upper module 20 and the upper surface 32 of the lower module 30 are each flat, the power storage device 200 has projections and recesses formed on the lower surface of the upper module and the upper surface of the lower module. The same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and repeated description will not be provided.

[0052] 3 is a cross-sectional view showing the configuration of the power storage device 200. The power storage device 200 includes a power storage module 110. The power storage module 110 includes an upper module 120 and a lower module 130. The upper module 120 and the lower module 130 are examples of the "first module" and the "second module" of the present disclosure, respectively.

[0053] Upper module 120 includes a lower surface 123. Lower module 130 includes an upper surface 132. Although not shown in FIG. 3 , a thermally conductive material may be provided between lower surface 123 and upper surface 132. Lower surface 123 and upper surface 132 are examples of the "second surface" and "third surface," respectively, of the present disclosure.

[0054] Concave and convex portions are formed on each of the lower surface 123 and the upper surface 132. Specifically, a plurality of convex portions 123a and a plurality of concave portions 123b are formed on the lower surface 123. A plurality of convex portions 132a and a plurality of concave portions 132b are formed on the upper surface 132. The convex portions 123a and the concave portions 123b are examples of the "first convex portion" and the "first concave portion" of the present disclosure, respectively. The convex portions 132a and the concave portions 132b are examples of the "second convex portion" and the "second concave portion" of the present disclosure, respectively.

[0055] In the second embodiment, the protrusions 123a are fitted into the recesses 132b. Also, the protrusions 132a are fitted into the recesses 123b. Specifically, each of the plurality of protrusions 123a is fitted into a different recess 132b. Each of the plurality of protrusions 132a is fitted into a different recess 123b.

[0056] The height h1 of the convex portion 123a (the depth of the concave portion 123b) is equal to the height h2 of the convex portion 132a (the depth of the concave portion 132b).

[0057] FIG. 4 is a plan view of the lower surface 123 of the upper module 120 as viewed from below. In FIG. 4, the convex portions 123a are represented by white portions, and the concave portions 123b are represented by hatched portions. As shown in FIG. 4, the convex portions 123a and the concave portions 123b are arranged in a matrix on the lower surface 123. Specifically, on the lower surface 123, the convex portions 123a and the concave portions 123b are arranged alternately in the X direction, and the convex portions 123a and the concave portions 123b are arranged alternately in the Y direction. As a result, the convex portions 123a and the concave portions 123b are arranged in a staggered pattern on the lower surface 123.

[0058] 4, recess 123b is formed by being surrounded by four (or three) protrusions 123a on the outer periphery of lower surface 123. Recess 123b is formed by side surfaces 123c of the four (or three) protrusions 123a and ceiling surface 123d connecting the upper ends of side surfaces 123c.

[0059] The protrusion 123a has a width W1 in the X direction. The protrusion 123a has a width W2 in the Y direction. The width W1 is equal to the width W2. That is, the bottom end surface 123e of the protrusion 123a has a square shape.

[0060] FIG. 5 is a plan view of the upper surface 132 of the lower module 130 as seen from above. In FIG. 5, the convex portions 132a are represented by white portions, and the concave portions 132b are represented by hatched portions. As shown in FIG. 5, the convex portions 132a and the concave portions 132b are arranged in a matrix on the upper surface 132. Specifically, on the upper surface 132, the convex portions 132a and the concave portions 132b are arranged alternately in the X direction, and the convex portions 132a and the concave portions 132b are arranged alternately in the Y direction. As a result, the convex portions 132a and the concave portions 132b are arranged in a staggered pattern on the upper surface 132.

[0061] 5, the recess 132b is formed by being surrounded by four (or three) protrusions 132a on the outer periphery of the upper surface 132. The recess 132b is formed by side surfaces 132c of the four (or three) protrusions 132a and a bottom surface 132d connecting the lower ends of the side surfaces 132a.

[0062] The protrusion 132a has a width W3 in the X direction. The protrusion 132a has a width W4 in the Y direction. The width W3 is equal to the width W4. That is, the upper end surface 132e of the protrusion 132a has a square shape. The width W3 (W4) is equal to the width W1 (W2) of the protrusion 123a of the upper module 120.

[0063] The protrusions 123a (FIG. 4) are fitted into the recesses 132b, and thus their movement in the X and Y directions is restricted by the four protrusions 132a surrounding the recesses 132b. Furthermore, the protrusions 132a are fitted into the recesses 123b (FIG. 4), and thus their movement in the X and Y directions is restricted by the four protrusions 123a surrounding the recesses 123b. Opposing side surfaces 123c (FIG. 4) and 132c are in contact (close contact). Furthermore, the lower end surface 123e (FIG. 4) of the protrusions 123a is in contact (close contact) with the bottom surface 132d of the recesses 132b. Furthermore, the upper end surface 132e of the protrusions 132a is in contact (close contact) with the ceiling surface 123d (FIG. 4) of the recesses 123b.

[0064] The other configurations are the same as those in the first embodiment, and therefore will not be described again.

[0065] [Variations] In the first embodiment described above, an example was shown in which the side surface 35 of the lower module 30 contacts the first bracket 51, but the present disclosure is not limited to this.

[0066] 6 includes a fixing bracket 150. The fixing bracket 150 includes a first bracket 151 and a second bracket 152. The first bracket 151 includes a first portion 151a, a second portion 151b, and a third portion 151c.

[0067] The first portion 151a is connected to the second bracket 52 and is in contact with the side surface 25 of the upper module 20. The lower end of the first portion 151a is located on the Z1 side of the upper surface 32 of the lower module 30.

[0068] The second portion 151b is disposed (fastened) to the bottom plate 41 of the case 40. The end of the second portion 151b on the power storage module 10 side (X1 side) is spaced apart from the side surface 35 of the lower module 30.

[0069] The third portion 151c connects the first portion 151a and the second portion 151b. The third portion 151c is spaced apart from the side surface 35. Alternatively, the third portion 151c may not be provided, and the first portion 151a and the second portion 151b may be directly connected to each other. Alternatively, the first bracket 151 may be formed by bending a single metal plate.

[0070] 6, the contact area between the side surface 35 and the fixing bracket 150 is 0. Therefore, the contact area between the lower module 30 and the fixing bracket 150 is also 0.

[0071] In the first embodiment described above, an example has been shown in which the energy storage cells 21 are arranged closer to the upper surface 22 and the energy storage cells 31 are arranged closer to the lower surface 33, but the present disclosure is not limited to this. For example, the energy storage cells 21 may be provided at positions closer to the Z2 side than the center (position P1) of the upper module 20. Specifically, the energy storage cells 21 may be arranged on the lower surface 23 of the upper module 20. This modification may also be applied to the second embodiment described above.

[0072] In the first embodiment described above, an example was shown in which the thermally conductive material 70 was provided between the upper module 20 and the lower module 30, but the present disclosure is not limited to this. The upper module 20 and the lower module 30 may be in direct contact with each other without the thermally conductive material 70 therebetween. Also, instead of the thermally conductive material 70, a metal plate member, for example, may be provided. The plate member is an example of a "thermally conductive member" in the present disclosure.

[0073] In the first embodiment, an example in which the energy storage module 10 includes two modules (20, 30) has been described, but the present disclosure is not limited to this. The energy storage module may include three or more modules. This modification may also be applied to the second embodiment.

[0074] In the first embodiment, the upper module 20 and the lower module 30 are stacked (arranged) in the vertical direction, but the present disclosure is not limited to this. The upper module 20 and the lower module 30 may be stacked (arranged) in a direction other than the vertical direction (for example, the X direction or the Y direction). This modification may also be applied to the second embodiment.

[0075] In the first embodiment, the upper module 20 and the lower module 30 have the same shape and size, but the present disclosure is not limited to this. At least one of the shape and size of the upper module 20 and the lower module 30 may be different. This modification may also be applied to the second embodiment.

[0076] The configurations of the above-described embodiment and the above-described modifications may be combined with each other.

[0077] 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 description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0078] 10,110 Energy storage module, 20,120 Upper module (first module), 21 Energy storage cell (first energy storage cell), 22 Upper surface (first surface), 23,123 Lower surface (second surface), 31 Energy storage cell (second energy storage cell), 32,132 Upper surface (third surface), 33 Lower surface (fourth surface), 30,130 Lower module (second module), 40 Case (arrangement member), 50,150 Fixing bracket, 70 Thermal conductive material (thermal conductive member), 100,200,300 Energy storage device, 123a Convex portion (first convex portion), 123b Concave portion (first concave portion), 132a Convex portion (second convex portion), 132b Concave portion (second concave portion).

Claims

1. a power storage module; an arrangement member on which the power storage module is arranged; a fixing bracket that fixes the power storage module to the arrangement member, the power storage module includes a first module and a second module stacked in a stacking direction, the first module has a first surface and a second surface arranged in the stacking direction; the second module has a third surface and a fourth surface arranged in the stacking direction; the second surface and the third surface are opposed to each other in the stacking direction, the fourth surface is in contact with the positioning member; a contact area between the fixing bracket and the first module is larger than a contact area between the fixing bracket and the second module.

2. the first module includes a first storage cell; the second module includes a second storage cell; the first surface is in contact with the fixed bracket; the first storage cell is disposed at a position closer to the first surface than a center of the first module in the stacking direction, The energy storage device according to claim 1 , wherein the second energy storage cell is disposed at a position closer to the fourth surface than a center of the second module in the stacking direction.

3. The power storage device according to claim 1 , further comprising a thermally conductive member sandwiched between the first module and the second module.

4. each of the second surface and the third surface has an uneven surface formed thereon; the irregularities on the second surface include a first convex portion and a first concave portion, the irregularities on the third surface include a second convex portion and a second concave portion, the first protrusion is fitted into the second recess, The power storage device according to claim 1 , wherein the second protrusion is fitted into the first recess.

5. The power storage device according to claim 1 or 2, wherein a contact area between the second module and the fixing bracket is zero.

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