Electricity storage device

Abstract

The electric power storage device comprises an electric power storage module comprising a plurality of electric power storage cells, a bonding material for bonding the plurality of electric power storage cells, and a bus bar between the electric power storage cells. Each of the plurality of storage cells includes a first short side surface and a second short side surface, a negative electrode terminal provided on the first short side surface, and a positive electrode terminal provided on the second short side surface. The plurality of storage cells are arranged such that the positive electrode terminals and the negative electrode terminals of the storage cells adjacent in the Y direction are adjacent to each other. The inter-cell bus bars connect the adjacent positive and negative terminals. The binding material binds the first short side and the second short side.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a power storage device. BACKGROUND

[0002] A battery pack in which sub-modules each including a plurality of unit cells are connected to each other by bus bars is disclosed in Japanese Laid-Open Patent Publication No. 2022-512496.

[0003] It can be considered that, in the battery pack described in Japanese Laid-Open Patent Publication No. 2022-512496, the bus bars are damaged due to positional displacement between the sub-modules when an impact is applied from the outside or the like. SUMMARY

[0004] The present disclosure has been achieved in order to solve the above problem, and has an object to provide a power storage device capable of inhibiting damage to bus bars that connect power storage cells to each other.

[0005] A power storage device according to an aspect of the present disclosure includes: a power storage module including a plurality of power storage cells arranged in a first direction; a case accommodating the power storage module; an adhesive material that adheres the plurality of power storage cells to each other; and a cell-to-cell bus bar that connects power storage cells adjacent to each other in the first direction among the plurality of power storage cells to each other. The plurality of power storage cells each include a side surface in a second direction that intersects the first direction, and a terminal provided to the side surface. The plurality of power storage cells are arranged such that the terminals of the power storage cells adjacent to each other in the first direction are adjacent to each other. The cell-to-cell bus bar connects the adjacent terminals to each other. The adhesive material adheres the side surfaces adjacent to each other in the first direction to each other.

[0006] In the power storage device according to an aspect of the present disclosure, as described above, the adhesive material adheres the side surfaces adjacent to each other in the first direction to each other. Thus, it is possible to inhibit positional displacement between the power storage cells (side surfaces) adjacent to each other in the first direction by the adhesive material. As a result, it is possible to inhibit stress from being applied to the cell-to-cell bus bar that connects the terminals respectively provided to the adjacent side surfaces to each other due to the positional displacement. Thus, it is possible to inhibit damage to the cell-to-cell bus bar.

[0007] The adhesive material can also adhere the side surfaces adjacent to each other provided to the adjacent terminals connected by the cell-to-cell bus bar to each other. With such a structure, it is possible to adhere the side surfaces connected (fixed) to each other by the cell-to-cell bus bar by the adhesive material, and thus it is possible to further inhibit stress from being applied to the cell-to-cell bus bar due to the positional displacement.

[0008] The adhesive material can also include a first adhesive portion and a second adhesive portion provided so as to be interposed between the inter-cell bus bars. With such a structure, compared to a case where the adhesive material includes only either the first adhesive portion or the second adhesive portion, the adjacent side surfaces can be more stably (firmly) fixed to each other. As a result, the inter-cell bus bars can be further inhibited from being damaged.

[0009] The power storage device can also be provided with a cooler including cooling surfaces on which a plurality of power storage cells are arranged. The adhesive material can be provided on the cooler side with respect to the inter-cell bus bars. With such a structure, the inter-cell bus bars can be easily inhibited from being displaced in position between the side surfaces on the cooler side. Therefore, this is particularly effective in a case where the above-described positional displacement is likely to occur on the cooler side due to weak adhesion between the power storage cells and the cooler.

[0010] The adhesive material can also have a belt shape extending in the first direction. With such a structure, the adhesive material can be easily made to have a large adhesive area with the side surfaces. As a result, the adhesive force formed by the adhesive material can be easily made large.

[0011] According to the present disclosure, the inter-cell bus bars connecting the power storage cells to each other can be inhibited from being damaged.

[0012] Features, advantages, and technical and industrial significance of exemplary embodiments of the present application will be described below with reference to the accompanying drawings, wherein the same reference numerals in different drawings denote the same element. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a view showing the structure of a vehicle on which a power storage device according to one embodiment is mounted.

[0014] Figure 2 is an exploded perspective view showing the structure of a power storage device and a vehicle frame according to one embodiment.

[0015] Figure 3 is an exploded perspective view showing the detailed structure of a power storage device according to one embodiment.

[0016] Figure 4 is a perspective view showing the structure of a power storage cell according to one embodiment.

[0017] Figure 5 is a sectional view showing the structure of a power storage device according to one embodiment.

[0018] Figure 6 is a plan view showing the structure of a power storage device according to one embodiment. DETAILED DESCRIPTION

[0019] Hereinafter, embodiments and modifications according to the present disclosure will be described with reference to the accompanying drawings. In the following description, the same parts and constituent elements are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated. Furthermore, the embodiments and modifications described below can also be appropriately combined selectively.

[0020] Referring to Figures 1-6 , a vehicle provided with the power storage device according to the present embodiment will be described. Figure 1 is a side view schematically showing a vehicle 200 provided with the power storage device 100 according to the present embodiment. Furthermore, the X direction, the Y direction, and the Z direction of the present specification are mutually orthogonal directions. For example, the X direction and the Y direction are the front-rear direction and the width direction of the vehicle 200 in the case where the power storage device 100 is mounted on the vehicle 200, respectively. In addition, the Z direction is the vertical direction. Furthermore, the X direction and the Y direction are examples of the "second direction" and the "first direction" of the present disclosure, respectively.

[0021] Referring to Figure 1 , the power storage device 100 is disposed below a floor panel 213 Figure 2 ) of the vehicle 200. As examples of the vehicle 200, a hybrid vehicle, a plug-in hybrid vehicle, a fuel cell vehicle, and an electric vehicle can be given. The vehicle 200 is provided with the power storage device 100 and a vehicle frame 210.

[0022] Figure 2 is an exploded perspective view schematically showing the power storage device 100 and the vehicle frame 210. Referring to Figure 2 , the vehicle frame 210 includes a left frame 211 and a right frame 212.

[0023] 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 apart from each other in the width direction (Y direction) of the vehicle 200. In addition, the left frame 211 and the right frame 212 are each disposed so as to extend in the front-rear direction (X direction) of the vehicle 200.

[0024] The 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 is fixed to the left frame 211 and the right frame 212.

[0025] Figure 3 is a perspective view schematically showing the power storage device 100. Referring to Figure 3 , the power storage device 100 is provided with a power storage module 1 including a plurality of power storage cells 10, and a case 20 that houses the power storage module 1.

[0026] The electricity storage battery cell 10 is a secondary battery, and is typically a lithium ion secondary battery. The lithium ion secondary battery is a battery that uses lithium as a charge carrier, and can include an all-solid battery that uses a solid electrolyte, in addition to a lithium ion secondary battery in which an electrolyte is a liquid. Furthermore, the electricity storage battery cell 10 is not limited to a lithium ion secondary battery, and can be constituted by a nickel-hydrogen secondary battery or another secondary battery.

[0027] The plurality of electricity storage battery cells 10 are respectively arranged so as to extend in the front-rear direction (X direction) of the vehicle 200 (refer to Figure 1 ). In addition, the plurality of electricity storage battery cells 10 are arranged in the width direction (Y direction) of the vehicle 200.

[0028] The housing 20 includes an upper cover 21 and a lower housing 22. The state of the electricity storage device 100 after the upper cover 21 is removed is shown in Figure 3 . The lower housing 22 includes a bottom plate 22a, a peripheral wall 22b, and a plurality of partition walls 22c, 22d, 22e, 22f, 22g. The plurality of partition walls 22c, 22d, 22e, 22f, 22g divide the spaces within the plurality of housings 20.

[0029] The bottom plate 22a is formed in a flat plate shape. The peripheral wall 22b is formed so as to extend from the outer peripheral edge portion of the bottom plate 22a toward the upper side of the vehicle 200. The peripheral wall 22b is formed in a ring shape. The partition walls 22c, 22d, 22e, 22f, 22g are provided to the bottom plate 22a. The partition walls 22c, 22d, 22e, 22f are formed so as to extend in the front-rear direction (X direction) of the vehicle 200. The partition wall 22g is formed so as to extend in the width direction (Y direction) of the vehicle 200.

[0030] The partition wall 22g is arranged at the center in the front-rear direction (X direction) of the vehicle 200. The partition wall 22c and the partition wall 22f are respectively arranged at the center in the width direction (Y direction) of the vehicle 200. The partition wall 22c is arranged at a position that is on the front side (X1 side) of the partition wall 22g with respect to the vehicle 200. The partition wall 22f is arranged at a position that is on the rear side (X2 side) of the partition wall 22g with respect to the vehicle 200. The plurality of electricity storage battery cells 10 are housed in each of the spaces divided by the partition wall 22c, the partition wall 22d, the partition wall 22e, the partition wall 22f, and the partition wall 22g.

[0031] The lower housing 22 further includes a plurality of support portions 22h and a plurality of support portions 22i. The support portions 22h and the support portions 22i are respectively fixed to the vehicle frame 210 Figure 2 ). For example, the support portions 22h and the support portions 22i are respectively formed with holes into which bolts are inserted. By inserting the bolts into the holes, the plurality of support portions 22h are respectively fixed to the left frame 211 Figure 2 , and the plurality of support portions 22i are respectively fixed to the right frame 212 Figure 2).

[0032] Figure 4 An example of the power storage cell 10 is shown. Referring to Figure 4 , the power 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. Further, the short side surface 13 and the short side surface 14 are each an example of a "side surface" of the present disclosure.

[0033] The upper surface 11 and the lower surface 12 are each a surface in the Z direction in the power storage cell 10. Specifically, the upper surface 11 is an end surface on the Z1 side in the power storage cell 10. The lower surface 12 is an end surface on the Z2 side in the power storage cell 10, and is a surface provided on the side opposite to the upper surface 11 in the Z direction.

[0034] The short side surface 13 and the short side surface 14 are each a surface in the X direction in the power storage cell 10. Specifically, the short side surface 13 and the short side surface 14 are each one end surface and the other end surface in the X direction in the power storage cell 10.

[0035] The long side surface 15 and the long side surface 16 are each a surface in the Y direction in the power storage cell 10. Specifically, the long side surface 15 and the long side surface 16 are each one end surface and the other end surface in the Y direction in the power storage cell 10.

[0036] The power storage cell 10 is configured to have a long side direction in the X direction. Specifically, the width W1 of the power storage cell 10 in the X direction is greater than the width W2 of the power storage cell 10 in the Y direction. In addition, the width W1 is greater than the height H of the power storage cell 10 in the Z direction. Further, the height H is greater than the width W2.

[0037] The power storage cell 10 further includes a positive electrode terminal 17 and a negative electrode terminal 18. The positive electrode terminal 17 is provided to the short side surface 14. The negative electrode terminal 18 is provided to the short side surface 13. Further, the positive electrode terminal 17 and the negative electrode terminal 18 are each an example of a "terminal" of the present disclosure.

[0038] Figure 5 is a cross-sectional view schematically showing the floor panel 213 and the power storage device 100. In Figure 5 , the short side surface 13 and the short side surface 14 are shown as viewed from the X1 side.

[0039] Referring to Figure 5 , in the power storage device 100, the power storage cell 10 configured so that the short side surface 13 faces the front (X1 side) of the vehicle 200 (refer to Figure 1 ) and the power storage cell 10 configured so that the short side surface 14 faces the front of the vehicle 200 are alternately arranged along the width direction (Y direction) of the vehicle 200. Thus, the positive electrode terminals 17 and the negative electrode terminals 18 of the power storage cells 10 configured to be adjacent to each other in the Y direction are adjacent to each other.

[0040] The electricity storage device 100 is provided with an adhesive material 30 that adheres the electricity storage cells 10 to the upper cover 21. The adhesive material 30 is made of resin. The adhesive material 30 is provided to the upper surface 11 of the electricity storage cell 10. More specifically, the adhesive material 30 is provided between the upper surface 11 of the electricity storage cell 10 and the upper cover 21 along the upper surface 11. The plurality of electricity storage cells 10 are fixed to the upper cover 21 by the adhesive material 30.

[0041] The electricity storage device 100 is also provided with a cooler 40 that cools the electricity storage cells 10. The cooler 40 has a cooling surface 41 on which the plurality of electricity storage cells 10 are arranged. The cooling surface 41 is an end surface on the Z1 side in the cooler 40. The cooler 40 (the cooling surface 41) is provided along the lower surface 12 of the electricity storage cell 10. Further, in the Figure 5 , an example in which no adhesive material (adhesive layer) is provided between the cooling surface 41 and the lower surface 12 of the electricity storage cell 10 is shown, but the adhesive material (adhesive layer) can be arranged at this position.

[0042] The electricity storage device 100 is also provided with an insulating plate 50. The insulating plate 50 is provided along the bottom plate 22a between the cooler 40 and the bottom plate 22a.

[0043] The electricity storage device 100 is provided with a plurality of inter-cell bus bars 60. The inter-cell bus bars 60 connect the electricity storage cells 10 adjacent in the Y direction to each other. Specifically, the inter-cell bus bars 60 connect the positive electrode terminals 17 and the negative electrode terminals 18 of the adjacent electricity storage cells 10. In detail, the inter-cell bus bars 60 connect the positive electrode terminal 17 provided to one of two electricity storage cells 10 adjacent in the Y direction and the negative electrode terminal 18 provided to the other of the two electricity storage cells 10.

[0044] Further, as shown in Figure 6 , on the X2 side, which is the side opposite to the X1 side shown in Figure 5 , the inter-cell bus bars 60 also connect the positive electrode terminals 17 and the negative electrode terminals 18 of the adjacent electricity storage cells 10. Each of the electricity storage cells 10 (the electricity storage cells 10 other than the both ends in the Y direction) is connected to the electricity storage cell 10 arranged on one side in the Y direction through the inter-cell bus bar 60 on the X1 side, and is connected to the electricity storage cell 10 arranged on the other side in the Y direction through the inter-cell bus bar 60 on the X2 side. Thus, the plurality of electricity storage cells 10 arranged in the Y direction are electrically connected in series.

[0045] Here, it can be considered that, in the conventional electricity storage device, the inter-cell bus bar is damaged due to a positional displacement between the adjacent electricity storage cells 10 when an impact is applied from the outside or the like.

[0046] Therefore, in the present embodiment, referring again to Figure 5, the power storage device 100 is provided with the adhesive material 70 that adheres the short side surface 13 and the short side surface 14 adjacent in the Y direction. Specifically, the adhesive material 70 adheres the short side surface 14 and the short side surface 13 of the positive electrode terminal 17 and the negative electrode terminal 18, respectively, which are connected by the inter-cell bus bar 60. Thus, on the X1 side and the X2 side of the power storage module 1, the combination of the power storage cells 10 adhered by the adhesive material 70 is different (refer to Figure 6 ).

[0047] Further, as shown in Figure 5 , the adhesive material 70 includes a first adhesive portion 71 and a second adhesive portion 72. Each of the inter-cell bus bars 60 is disposed so as to be sandwiched between the first adhesive portion 71 and the second adhesive portion 72. Specifically, the first adhesive portion 71 is provided on the Z1 side of the inter-cell bus bar 60. The second adhesive portion 72 is provided on the Z2 side of the inter-cell bus bar 60. Further, the first adhesive portion 71 and the second adhesive portion 72 have the same shape and size.

[0048] The second adhesive portion 72 is provided on the cooler 40 side with respect to 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.

[0049] Further, each of the inter-cell bus bars 60 is disposed at a position lower (Z2 side) than the center in the Z direction in the power storage cell 10. In contrast to this, the first adhesive portion 71 is provided near the center in the Z direction in the power storage cell 10. Further, the second adhesive portion 72 is provided near the lower surface 12 of the power storage cell 10.

[0050] The adhesive material 70 (71, 72) has a belt shape that extends in the Y direction. The adhesive material 70 has a width W11 in the Y direction. The adhesive material 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.

[0051] The width W11 of the adhesive material 70 in the Y direction is, for example, larger than the width W2( Figure 4 ) of the power storage cell 10 in the Y direction. Further, the width W11 is 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.

[0052] As described above, in the above-described embodiment, the adhesive material 70 adheres the short side surface 13 and the short side surface 14 adjacent in the Y direction. Thus, the adjacent power storage cells 10 are fixed to each other by the adhesive material 70, and thus it is possible to suppress stress from being applied to the inter-cell bus bar 60 that connects the adjacent power storage cells 10 to each other. As a result, it is possible to suppress damage to the inter-cell bus bar 60.

[0053] Further, in the above embodiment, the second adhesive portion 72 is provided on the side of the cooler 40 with respect to the inter-cell bus bar 60. Thus, even if the respective storage battery cells 10 are not adhered to the cooler 40, it is possible to suppress positional displacement between the portions of the adjacent storage battery cells 10 on the side of the cooler 40 from each other by the second adhesive portion 72.

[0054] In the above embodiment, an example in which the negative electrode terminal 18 is provided on the short side surface 13 of the storage battery cell 10 and the positive electrode terminal 17 is provided on the short side surface 14 of the storage battery cell 10 is shown, but the present disclosure is not limited thereto. The positive electrode terminal 17 and the negative electrode terminal 18 can be provided on either one of the short side surface 13 and the short side surface 14, respectively. In this case, the adjacent short side surfaces (13 or 14) on which the terminals (17, 18) are provided are adhered to each other by the adhesive material. Further, the adjacent short side surfaces (13 or 14) on which the terminals (17, 18) are not provided can also be adhered to each other by the adhesive material.

[0055] In the above embodiment, an example in which the adjacent storage battery cells 10 are adhered to each other by the first adhesive portion 71 and the second adhesive portion 72 is shown, but the present disclosure is not limited thereto. The adjacent storage battery cells 10 can be adhered to each other by only either one of the first adhesive portion 71 and the second adhesive portion 72.

[0056] In the above embodiment, an example in which the adhesive material 70 adheres the side surfaces (13, 14) on which the terminals (17, 18) connected by the inter-cell bus bar 60 are provided to each other is shown, but the present disclosure is not limited thereto. For example, the adhesive material can also adhere the adjacent side surfaces (13, 14) on which the terminals (17, 18) not connected by the inter-cell bus bar 60 are provided to each other.

[0057] In the above embodiment, an example in which the respective adhesive materials 70 adhere the adjacent two storage battery cells 10 to each other is shown, but the present disclosure is not limited thereto. The adjacent three or more storage battery cells 10 can also be adhered to each other by the adhesive material.

[0058] In the above embodiment, an example in which the first adhesive portion 71 and the second adhesive portion 72 have the same shape and size is shown, but the present disclosure is not limited thereto. The first adhesive portion and the second adhesive portion can have different shapes and sizes. For example, the width in the Y direction of the second adhesive portion can be larger than the width in the Y direction of the first adhesive portion. Further, the thickness in the X direction of the second adhesive portion can be larger than the thickness in the X direction of the first adhesive portion.

[0059] In the above embodiment, an example in which the cooler 40 is provided below the storage battery cell 10 is shown, but the present disclosure is not limited thereto. The cooler can also be provided above the storage battery cell.

[0060] In the above-described embodiment, an example in which the plurality of power storage cells 10 are arranged in the Y direction orthogonal (crossing) to the Z direction (the up-down direction) is shown, but the present disclosure is not limited thereto. For example, the plurality of power storage cells 10 can also be arranged (stacked) in the Z direction.

[0061] In the above-described embodiment, an example in which the power storage device 100 is mounted on the vehicle 200 is shown, but the present disclosure is not limited thereto. The power storage device 100 can also be provided to an electrical device other than a vehicle (for example, a stationary power storage device).

[0062] In the above-described embodiment, an example in which the first adhesive portion 71 is provided at the center in the Z direction of the power storage cell 10 is shown, but the present disclosure is not limited thereto. For example, the first adhesive portion 71 can also be provided at the upper portion (for example, in the vicinity of the upper surface 11) of the power storage cell 10.

[0063] In the above-described embodiment, an example in which the adhesive material 70 (71, 72) extends in the Y direction is shown, but the present disclosure is not limited thereto. The adhesive material 70 (71, 72) can also extend in the Z direction. In addition, the adhesive material 70 (71, 72) can also extend so as to cross the Z direction and the Y direction, respectively.

[0064] In the above-described embodiment, an example in which the adhesive material 70 (71, 72) has a band shape is shown, but the present disclosure is not limited thereto. The adhesive material 70 (71, 72) can also have a shape other than a band shape (for example, a square shape and a circular shape, and the like).

[0065] The embodiments of the present disclosure should be considered in all respects as illustrative and not restrictive. The scope of the present disclosure is indicated not by the above description but by the claims, and is intended to encompass meanings equivalent to the claims and all modifications within the scope.

Claims

1. A power storage device, wherein the power storage device is provided with: a power storage module including a plurality of power storage cells arranged in a first direction; a case accommodating the power storage module; an adhesive material adhering the plurality of power storage cells to each other; and an inter-cell bus bar connecting power storage cells adjacent in the first direction among the plurality of power storage cells to each other, the plurality of power storage cells each include: a side surface in a second direction intersecting the first direction; and a terminal provided to the side surface, the plurality of power storage cells are arranged such that the terminals of the power storage cells adjacent in the first direction are adjacent to each other, the inter-cell bus bar connects the adjacent terminals to each other, and the adhesive material adheres the side surfaces adjacent in the first direction to each other.

2. The power storage device according to claim 1, wherein the adhesive material adheres the adjacent side surfaces each provided to the adjacent terminals connected by the inter-cell bus bar to each other.

3. The power storage device according to claim 1 or 2, wherein the adhesive material includes a first adhesive portion and a second adhesive portion provided with the inter-cell bus bar interposed therebetween.

4. The power storage device according to claim 1 or 2, wherein a cooler including a cooling surface arranged with the plurality of power storage cells is further provided, and the adhesive material is provided to the cooler side with respect to the inter-cell bus bar.

5. The power storage device according to claim 1 or 2, wherein the adhesive material has a belt shape extending in the first direction. ​

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