Power storage device

Abstract

To provide a power storage device that can prevent damage to bus bars that connect power storage cells to each other.SOLUTION: A power storage device 100 includes a power storage module 1 including a plurality of power storage cells 10, an adhesive 70 that bonds the plurality of power storage cells 10 together, and an inter-cell bus bar 60. Each of the plurality of power storage cells 10 includes a short side surface 13 (side surface) and a short side surface 14 (side surface), a negative electrode terminal 18 (terminal) provided on the short side surface 13, and a positive electrode terminal 17 (terminal) provided on the short side surface 14. The plurality of power storage cells 10 are arranged such that the positive electrode terminals 17 and the negative electrode terminals 18 of the power storage cells 10 adjacent to each other in the Y direction (first direction) are adjacent to each other. The inter-cell bus bar 60 connects the adjacent positive electrode terminals 17 and the negative electrode terminals 18. The adhesive 70 bonds the short side surfaces 13 and the short side surfaces 14 that are adjacent to each other in the Y direction.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] JP-A-2022-512496 (Patent Document 1) discloses a battery pack in which sub-modules each including a plurality of unit cells are connected to each other by bus bars. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2022-512496 Summary of the Invention [Problem to be solved by the invention]

[0004] In the battery pack described in Patent Document 1, when an external impact is applied, the bus bars may be damaged due to misalignment between the sub-modules.

[0005] The present disclosure has been made to solve the above-described problems, and its purpose is to provide an energy storage device that can prevent damage to bus bars that connect energy storage cells to each other. [Means for solving the problem]

[0006] An energy storage device according to one aspect of the present disclosure includes: an energy storage module including a plurality of energy storage cells arranged in a first direction; a case that houses the energy storage module; an adhesive that bonds the plurality of energy storage cells together; and an inter-cell bus bar that connects adjacent energy storage cells in the first direction among the plurality of energy storage cells. Each of the plurality of energy storage cells includes a side surface in a second direction that intersects the first direction and a terminal provided on the side surface. The plurality of energy storage cells are arranged such that the terminals of adjacent energy storage cells in the first direction are adjacent to each other. The inter-cell bus bar connects adjacent terminals to each other. The adhesive bonds adjacent side surfaces in the first direction to each other.

[0007] In the energy storage device according to one aspect of the present disclosure, as described above, the adhesive bonds the side surfaces adjacent in the first direction. This allows the adhesive to prevent misalignment between the energy storage cells (side surfaces) adjacent in the first direction. As a result, it is possible to prevent stress caused by the misalignment from being applied to the inter-cell bus bars connecting the terminals provided on the adjacent side surfaces. This makes it possible to prevent damage to the inter-cell bus bars.

[0008] The adhesive may bond adjacent side surfaces on which adjacent terminals connected by the inter-cell bus bar are provided. With this configuration, the side surfaces connected (fixed) by the inter-cell bus bar can be bonded with the adhesive, which further reduces stress on the inter-cell bus bar due to the misalignment.

[0009] The adhesive may include a first adhesive portion and a second adhesive portion that sandwich the inter-cell bus bar. This configuration allows adjacent side surfaces to be fixed more stably (strongly) than when the adhesive includes only one of the first adhesive portion and the second adhesive portion. As a result, damage to the inter-cell bus bar can be further suppressed.

[0010] The energy storage device may include a cooler including a cooling surface on which a plurality of energy storage cells are arranged. The adhesive may be provided on the cooler side relative to the inter-cell bus bar. This configuration can easily prevent misalignment between the side surfaces of the inter-cell bus bar on the cooler side. This is particularly effective when the adhesive strength between the energy storage cells and the cooler is relatively weak, making the misalignment likely to occur on the cooler side.

[0011] The adhesive may have a strip shape extending in the first direction. This configuration makes it possible to easily increase the bonding area between the adhesive and the side surface, thereby easily increasing the adhesive strength of the adhesive. [Effects of the Invention]

[0012] According to the present disclosure, it is possible to prevent damage to the bus bars that connect the energy storage cells to each other. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a diagram showing a configuration of a vehicle equipped with a power storage device according to an embodiment; [Figure 2] 1 is an exploded perspective view showing a configuration of an electricity storage device and a vehicle frame according to an embodiment; [Figure 3] FIG. 2 is an exploded perspective view showing a detailed configuration of the electricity storage device according to the embodiment. [Figure 4] FIG. 1 is a perspective view illustrating a configuration of a storage cell according to an embodiment. [Figure 5] 1 is a cross-sectional view showing a configuration of an electricity storage device according to an embodiment. [Figure 6] 1 is a plan view illustrating a configuration of an electricity storage device according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] 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.

[0015] A power storage device and a vehicle including the power storage device according to this embodiment will be described with reference to FIGS. 1 to 6. FIG. 1 is a side view that schematically shows a vehicle 200 including a power storage device 100 according to this 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 width direction of the vehicle 200 when the power storage device 100 is mounted on the vehicle 200, respectively. The Z direction is the vertical direction. The X direction and Y direction are examples of the "second direction" and "first direction" in the present disclosure, respectively.

[0016] 1, the power storage device 100 is disposed below a floor panel 213 (FIG. 2) of the vehicle 200. Examples of the vehicle 200 include a hybrid vehicle, a plug-in hybrid vehicle, a fuel cell vehicle, and an electric vehicle. The vehicle 200 includes the power storage device 100 and a vehicle frame 210.

[0017] 2 is an exploded perspective view schematically showing the power storage device 100 and a vehicle frame 210. Referring to FIG.

[0018] The left frame 211 and the right frame 212 are disposed at the bottom of the vehicle frame 210. The left frame 211 and the right frame 212 are disposed at an interval in the width direction (Y direction) of the vehicle 200. Furthermore, each of the left frame 211 and the right frame 212 is disposed so as to extend in the front-rear direction (X direction) of the vehicle 200.

[0019] A floor panel 213 is provided between the left frame 211 and the right frame 212. The power storage device 100 is disposed below the floor panel 213 and fixed to the left frame 211 and the right frame 212.

[0020] Fig. 3 is a perspective view that schematically shows the energy storage device 100. Referring to Fig. 3, the energy storage device 100 includes an energy storage module 1 that includes a plurality of energy storage cells 10, and a case 20 that houses the energy storage module 1.

[0021] The storage cell 10 is a secondary battery, typically a lithium-ion secondary battery. A lithium-ion secondary battery is a battery that uses lithium as a charge carrier, and may include not only lithium-ion secondary batteries that use a liquid electrolyte, but also all-solid-state batteries that use a solid electrolyte. Note that the storage cell 10 is not limited to a lithium-ion secondary battery, and may be composed of a nickel-metal hydride secondary battery or other secondary batteries.

[0022] Each of the plurality of energy storage cells 10 is arranged to extend in the front-rear direction (X direction) of the vehicle 200 (see FIG. 1). The plurality of energy storage cells 10 are also arranged in the width direction (Y direction) of the vehicle 200.

[0023] Case 20 includes an upper cover 21 and a lower case 22. Fig. 3 shows power storage device 100 with upper cover 21 removed. Lower case 22 includes a bottom plate 22a, a peripheral wall 22b, and a plurality of partition walls 22c, 22d, 22e, 22f, and 22g. Partition walls 22c, 22d, 22e, 22f, and 22g divide the space inside case 20 into a plurality of sections.

[0024] The bottom plate 22a is formed in a flat plate shape. The peripheral wall 22b is formed to extend from the outer peripheral edge of the bottom plate 22a toward the upper side of the vehicle 200. The peripheral wall 22b is formed in an annular shape. The partition walls 22c, 22d, 22e, 22f, and 22g are provided on the bottom plate 22a. The partition walls 22c, 22d, 22e, and 22f are formed to extend in the front-rear direction (X direction) of the vehicle 200. The partition wall 22g is formed to extend in the width direction (Y direction) of the vehicle 200.

[0025] Partition wall 22g is disposed at the center in the front-to-rear direction (X direction) of vehicle 200. Partition wall 22c and partition wall 22f are each disposed at the center in the width direction (Y direction) of vehicle 200. Partition wall 22c is disposed closer to the front (X1 side) of vehicle 200 than partition wall 22g. Partition wall 22f is disposed closer to the rear (X2 side) of vehicle 200 than partition wall 22g. A plurality of energy storage cells 10 are accommodated in each of the spaces partitioned by partition wall 22c, partition wall 22d, partition wall 22e, partition wall 22f, and partition wall 22g.

[0026] The lower case 22 further includes a plurality of support portions 22h and a plurality of support portions 22i. Each of the support portions 22h and 22i is fixed to the vehicle frame 210 (FIG. 2). For example, each of the support portions 22h and 22i has a hole formed therein into which a bolt is fitted. By fitting the bolt into the hole, each of the plurality of support portions 22h is fixed to the left frame 211 (FIG. 2), and each of the plurality of support portions 22i is fixed to the right frame 212 (FIG. 2).

[0027] Fig. 4 shows an example of a storage cell 10. Referring to Fig. 4, the storage cell 10 includes an upper surface 11, a lower surface 12, a short side surface 13, a short side surface 14, a long side surface 15, and a long side surface 16. Each of the short side surface 13 and the short side surface 14 is an example of a "side surface" in the present disclosure.

[0028] Each of the upper surface 11 and the lower surface 12 is a surface of the energy storage cell 10 facing in the Z direction. Specifically, the upper surface 11 is an end surface on the Z1 side of the energy storage cell 10. The lower surface 12 is an end surface on the Z2 side of the energy storage cell 10, and is a surface provided on the opposite side of the upper surface 11 in the Z direction.

[0029] Each of the short side surfaces 13 and 14 is a surface of the energy storage cell 10 facing in the X direction. Specifically, the short side surfaces 13 and 14 are one end surface of the energy storage cell 10 facing in the X direction and the other end surface of the energy storage cell 10 facing in the X direction, respectively.

[0030] Each of the long side surfaces 15 and 16 is a surface of the energy storage cell 10 facing in the Y direction. Specifically, the long side surfaces 15 and 16 are one end surface of the energy storage cell 10 facing in the Y direction and the other end surface of the energy storage cell 10 facing in the Y direction, respectively.

[0031] The energy storage cell 10 is configured to have a longitudinal direction in the X direction. Specifically, the width W1 of the energy storage cell 10 in the X direction is larger than the width W2 of the energy storage cell 10 in the Y direction. The width W1 is also larger than the height H of the energy storage cell 10 in the Z direction. The height H is also larger than the width W2.

[0032] The energy storage cell 10 further includes a positive electrode terminal 17 and a negative electrode terminal 18. The positive electrode terminal 17 is provided on the short side surface 14. The negative electrode terminal 18 is provided on the short side surface 13. Each of the positive electrode terminal 17 and the negative electrode terminal 18 is an example of a "terminal" in the present disclosure.

[0033] Fig. 5 is a cross-sectional view that schematically shows floor panel 213 and power storage device 100. Fig. 5 also shows short side surface 13 and short side surface 14 as viewed from the X1 side.

[0034] 5, in the energy storage device 100, the energy storage cells 10 arranged so that the short side surfaces 13 face forward (X1 side) of the vehicle 200 (see FIG. 1) and the energy storage cells 10 arranged so that the short side surfaces 14 face forward of the vehicle 200 are alternately arranged along the width direction (Y direction) of the vehicle 200. As a result, the positive electrode terminals 17 and the negative electrode terminals 18 of the energy storage cells 10 adjacent to each other in the Y direction are arranged adjacent to each other.

[0035] The energy storage device 100 includes an adhesive 30 that adheres the energy storage cells 10 to the upper cover 21. The adhesive 30 is made of resin. The adhesive 30 is provided on the upper surface 11 of the energy storage cells 10. More specifically, the adhesive 30 is provided between the upper surface 11 of the energy storage cells 10 and the upper cover 21, along the upper surface 11. The plurality of energy storage cells 10 are fixed to the upper cover 21 by the adhesive 30.

[0036] The energy storage device 100 further includes a cooler 40 that cools the energy storage cells 10. The cooler 40 has a cooling surface 41 on which a plurality of energy storage cells 10 are arranged. The cooling surface 41 is an end surface of the cooler 40 on the Z1 side. The cooler 40 (cooling surface 41) is provided along the lower surface 12 of the energy storage cell 10. Note that while FIG. 5 shows an example in which no adhesive material (adhesive layer) is provided between the cooling surface 41 and the lower surface 12 of the energy storage cell 10, an adhesive material (adhesive layer) may be provided at this position.

[0037] The electricity storage device 100 further includes an insulating plate 50. The insulating plate 50 is provided along the bottom plate 22a between the cooler 40 and the bottom plate 22a.

[0038] The energy storage device 100 includes a plurality of inter-cell bus bars 60. The inter-cell bus bars 60 connect the energy storage cells 10 adjacent to each other in the Y direction. Specifically, the inter-cell bus bars 60 connect the positive electrode terminals 17 and negative electrode terminals 18 adjacent to each other. In more detail, the inter-cell bus bars 60 connect the positive electrode terminal 17 provided on one of two energy storage cells 10 adjacent to each other in the Y direction to the negative electrode terminal 18 provided on the other of the two energy storage cells 10.

[0039] 6, on the X2 side of the energy storage module 1 opposite to the X1 side shown in FIG. 5, the inter-cell bus bars 60 similarly connect adjacent positive electrode terminals 17 and negative electrode terminals 18. On the X1 side, each energy storage cell 10 (energy storage cells 10 other than those at both ends in the Y direction) is connected to the energy storage cell 10 arranged on one side in the Y direction by the inter-cell bus bars 60, and on the X2 side, each energy storage cell 10 is connected to the energy storage cell 10 arranged on the other side in the Y direction by the inter-cell bus bars 60. As a result, the multiple energy storage cells 10 arranged in the Y direction are electrically connected in series.

[0040] Here, in a conventional energy storage device, when an external impact is applied, it is conceivable that the inter-cell bus bar may be damaged due to misalignment occurring between adjacent energy storage cells 10.

[0041] 5, in this embodiment, the energy storage device 100 includes an adhesive 70 that bonds the short side surfaces 13 and 14 adjacent to each other in the Y direction. Specifically, the adhesive 70 bonds the short side surfaces 14 and 13 on which the positive electrode terminals 17 and negative electrode terminals 18 connected by the inter-cell bus bar 60 are provided, respectively. Therefore, the combinations of energy storage cells 10 bonded by the adhesive 70 differ between the X1 side and the X2 side of the energy storage module 1 (see FIG. 6).

[0042] 5, adhesive 70 includes a first adhesive portion 71 and a second adhesive portion 72. Each inter-cell bus bar 60 is sandwiched between first adhesive portion 71 and second adhesive portion 72. Specifically, first adhesive portion 71 is provided on the Z1 side of inter-cell bus bar 60. Second adhesive portion 72 is provided on the Z2 side of inter-cell bus bar 60. First adhesive portion 71 and second adhesive portion 72 have the same shape and size.

[0043] The second adhesive portion 72 is provided on the cooler 40 side of the inter-cell bus bar 60. In other words, the second adhesive portion 72 is disposed between the inter-cell bus bar 60 and the cooler 40.

[0044] Furthermore, each inter-cell bus bar 60 is disposed below (on the Z2 side of) the center of the energy storage cell 10 in the Z direction. In contrast, the first adhesive portion 71 is provided near the center of the energy storage cell 10 in the Z direction. Furthermore, the second adhesive portion 72 is provided near the lower surface 12 of the energy storage cell 10.

[0045] The adhesive 70 (71, 72) has a strip shape extending in the Y direction. The adhesive 70 has a width W11 in the Y direction. The adhesive 70 has a width W12 in the Z direction. The width W11 is larger than the width W12. The width W11 is, for example, four times or more the width W12.

[0046] The width W11 in the Y direction of the adhesive 70 is larger than, for example, the width W2 (FIG. 4) in the Y direction of the energy storage cell 10. The width W11 is also larger than the distance D in the Y direction between the positive electrode terminal 17 and the negative electrode terminal 18 connected by the inter-cell bus bar 60.

[0047] As described above, in the above embodiment, the adhesive 70 bonds the short side surfaces 13 and 14 adjacent to each other in the Y direction. This allows the adjacent energy storage cells 10 to be fixed together by the adhesive 70, thereby preventing stress from being applied to the inter-cell bus bars 60 that connect the adjacent energy storage cells 10. As a result, damage to the inter-cell bus bars 60 can be prevented.

[0048] Furthermore, in the above embodiment, the second adhesive portion 72 is provided on the cooler 40 side of the inter-cell bus bar 60. As a result, even if each energy storage cell 10 is not adhered to the cooler 40, the second adhesive portion 72 can prevent misalignment between the portions of adjacent energy storage cells 10 on the cooler 40 side.

[0049] In the above embodiment, an example has been shown in which the negative electrode terminal 18 is provided on the short side surface 13 of the energy storage cell 10 and the positive electrode terminal 17 is provided on the short side surface 14 of the energy storage cell 10, but the present disclosure is not limited to this. The positive electrode terminal 17 and the negative electrode terminal 18 may each be provided on either the short side surface 13 or the short side surface 14. In this case, adjacent short side surfaces (13 or 14) on which the terminals (17, 18) are provided are bonded together with an adhesive. Note that adjacent short side surfaces (13 or 14) on which the terminals (17, 18) are not provided may also be bonded together with an adhesive.

[0050] In the above embodiment, an example has been described in which adjacent energy storage cells 10 are bonded to each other by the first adhesive portion 71 and the second adhesive portion 72, but the present disclosure is not limited to this. Adjacent energy storage cells 10 may be bonded to each other by only one of the first adhesive portion 71 and the second adhesive portion 72.

[0051] In the above embodiment, an example has been shown in which the adhesive 70 bonds the side surfaces (13, 14) on which the terminals (17, 18) connected by the inter-cell bus bar 60 are provided, but the present disclosure is not limited to this. For example, the adhesive may bond adjacent side surfaces (13, 14) on which the terminals (17, 18) that are not connected by the inter-cell bus bar 60 are provided.

[0052] In the above embodiment, an example has been shown in which each adhesive 70 connects two adjacent energy storage cells 10 together, but the present disclosure is not limited to this. Three or more adjacent energy storage cells 10 may be bonded together with an adhesive.

[0053] In the above embodiment, the first adhesive portion 71 and the second adhesive portion 72 have the same shape and size, but the present disclosure is not limited to this. The first adhesive portion and the second adhesive portion may have different shapes and sizes. For example, the width of the second adhesive portion in the Y direction may be greater than the width of the first adhesive portion in the Y direction. Furthermore, the thickness of the second adhesive portion in the X direction may be greater than the thickness of the first adhesive portion in the X direction.

[0054] In the above embodiment, an example has been shown in which the cooler 40 is provided below the energy storage cells 10, but the present disclosure is not limited to this. The cooler may also be provided above the energy storage cells.

[0055] In the above embodiment, an example has been shown in which the plurality of energy storage cells 10 are arranged in the Y direction perpendicular to (intersecting with) the Z direction (vertical direction), but the present disclosure is not limited to this. For example, the plurality of energy storage cells 10 may be arranged (stacked) in the Z direction.

[0056] In the above embodiment, an example has been shown in which the power storage device 100 is mounted on the vehicle 200, but the present disclosure is not limited to this. The power storage device 100 may also be provided in an electrical device other than a vehicle (for example, a stationary power storage device).

[0057] In the above embodiment, an example has been described in which the first adhesive portion 71 is provided at the center of the energy storage cell 10 in the Z direction, but the present disclosure is not limited to this. For example, the first adhesive portion 71 may be provided at an upper portion of the energy storage cell 10 (for example, near the upper surface 11).

[0058] In the above embodiment, an example was shown in which the adhesive 70 (71, 72) extends in the Y direction, but the present disclosure is not limited to this. The adhesive 70 (71, 72) may extend in the Z direction. Furthermore, the adhesive 70 (71, 72) may extend so as to intersect with both the Z direction and the Y direction.

[0059] In the above embodiment, the adhesive 70 (71, 72) has a strip shape, but the present disclosure is not limited to this. The adhesive 70 (71, 72) may have a shape other than a strip shape (for example, a square shape, a circular shape, etc.).

[0060] 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]

[0061] 1 Energy storage module, 10 Energy storage cell, 13 Short side (side), 14 Short side (side), 17 Positive terminal (terminal), 18 Negative terminal (terminal), 20 Case, 40 Cooler, 41 Cooling surface, 60 Inter-cell bus bar, 70 Adhesive, 71 First adhesive portion, 72 Second adhesive portion, 100 Energy storage device, 200 Vehicle.

Claims

1. a power storage module including a plurality of power storage cells arranged in a first direction; a case that houses the power storage module; an adhesive that bonds the plurality of electricity storage cells together; an inter-cell bus bar connecting adjacent storage cells in the first direction among the plurality of storage cells, Each of the plurality of storage cells is a side surface in a second direction intersecting the first direction; a terminal provided on the side surface, the plurality of storage cells are arranged such that the terminals of the storage cells adjacent to each other in the first direction are adjacent to each other, the inter-cell bus bar connects adjacent terminals to each other, The adhesive bonds the side surfaces adjacent to each other in the first direction.

2. The power storage device according to claim 1 , wherein the adhesive bonds the adjacent side surfaces on which the adjacent terminals connected by the inter-cell bus bar are provided.

3. The power storage device according to claim 1 , wherein the adhesive material includes a first adhesive portion and a second adhesive portion that are provided so as to sandwich the inter-cell bus bar.

4. a cooler including a cooling surface on which the plurality of storage cells are arranged, The power storage device according to claim 1 , wherein the adhesive is provided on a side of the inter-cell bus bar that faces the cooler.

5. The power storage device according to claim 1 , wherein the adhesive material has a strip shape extending in the first direction.

Images