JP2023049482A - battery pack - Google Patents

Abstract

To provide a battery pack capable of reducing the number of components.SOLUTION: According to an embodiment of the present disclosure, there is provided a battery pack 1 in which a plurality of alignment grooves 58 are formed in the bottom 41 of a battery case 12. A battery cell 21 includes a plurality of alignment protrusions 46 regulated by the alignment grooves 58, respectively. In each of a first side wall 54 and a second side wall 55 of the battery case 12, a groove 56 regulating the height-direction position of each battery cell 21 included in a battery stack 11 is formed along the lamination direction of the battery stack 11. Each battery cell 21 included in the battery stack 11 includes a first flange 44 and a second flange 45 each of which is regulated by the groove 56.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to a battery pack having a battery stack in which battery cells are stacked and a case member that houses the battery stack.

As a conventional technology related to battery packs, Patent Document 1 discloses a power storage device. In the power storage device disclosed in Patent Document 1, a battery stack in which single cells (power storage elements) are stacked to form a module as an assembled battery is provided with end plates arranged on both sides in the stacking direction of the single cells in the battery stack. It is fastened and fixed to the pack case with bolts.

JP 2013-069657 A

In the power storage device disclosed in Patent Document 1, end plates are arranged on both sides of the battery stack in the stacking direction of the unit cells, and the battery stack is bolted to the pack case via the end plates, Large number of parts. And, if the number of parts is large in this way, the process of fixing the battery stack to the pack case becomes complicated. In addition, since the tolerances of many parts are accumulated, the electrode terminals of the cells cannot be accurately positioned, making it difficult to connect the electrode terminals and the busbar module. Moreover, a large amount of wasted space is generated in the power storage device, resulting in an increase in the size of the power storage device.

Therefore, the present disclosure has been made to solve the above-described problems, and an object thereof is to provide a battery pack capable of reducing the number of parts.

One aspect of the present disclosure, which has been made to solve the above problems, is a battery pack in which a plurality of battery cells are stacked and housed in a case member, and the case member has a plurality of battery cells arranged in a thickness direction. It has a bottom portion positioned below the stacked battery modules, and a first side wall portion and a second side wall portion positioned on both sides of the battery module, and the bottom portion is included in the battery module. A plurality of position regulating shape portions for regulating the position of each battery cell in the width direction are formed along the stacking direction of the battery module, and the first side wall portion and the second side wall portion each have: A height regulating shape portion for regulating a height direction position of each battery cell included in the battery module is formed along a stacking direction of the battery module, and each battery cell included in the battery module is , a plurality of position regulated portions regulated by the position regulating shape portion, and a first height regulated portion and a second height regulated portion regulated by the height regulated shape portion. and

According to this aspect, the position regulated portion of the battery cell is regulated by the position regulated portion of the case member, and the first height regulated portion and the second height regulated portion of the battery cell are adjusted to the height of the case member. It is regulated by the height regulating shape portion. As a result, it is possible to attach the battery stack to the case member and to position the case member and the battery cells without using dedicated attachment parts. Therefore, it is possible to attach the battery module to the case member and position the battery module with respect to the case member while reducing the number of parts of the battery pack.

In the above aspect, the individual battery cells included in the battery module are each fitted in the resin frame member, and the position-restricted portion, the first height-restricted portion, and the second height-restricted portion are are preferably formed on the resin frame member.

According to this aspect, since the position-restricted portion, the first height-restricted portion, and the second height-restricted portion are integrated into the resin frame member, the number of parts can be reduced more effectively.

In the above aspect, there is a gap between the bottom surface of the battery module and the portion of the bottom surface portion of the case member other than the position regulating shape portion, and the one side surface of the battery module and the case member are spaced apart from each other. There is a gap between the other side surface of the battery module and the second side wall portion of the case member other than the height regulating shape portion. It is preferable that there is a gap between the part of .

According to this aspect, the individual battery cells included in the battery module can be cooled by allowing the cooling air to flow inside the battery pack through the gap formed between the case member and the battery module.

In the above aspect, an end plate is attached to one end in the stacking direction of the battery module and allows each of the gaps to communicate with the outside, and the end plate includes a rigid member and an inner surface side of the rigid member. It is preferable that the resin member has a lip portion that is in close contact with the case member.

According to this aspect, since the lip portion of the resin member of the end plate is in close contact with the case member, it is possible to prevent the cooling air flowed inside the battery pack from escaping to the outside of the battery pack. Therefore, the battery cells can be efficiently cooled by the cooling air.

In the above aspect, the case member has an end wall located on one end side in the stacking direction of the battery module, and the battery module is attached to the case member in a state of being compressed in the stacking direction. It is preferable that fastening points to the device are provided at a plurality of locations in an area inside the end wall of the bottom surface portion in the stacking direction of the battery module.

According to this aspect, since the binding load in the stacking direction of the battery module acting on the end wall is less likely to act on the region inside the end wall in the stacking direction of the battery module, it is less likely to act on the fastening portion to the device. Become. Therefore, the battery pack can be stably fastened to the device.

According to the battery pack of the present disclosure, it is possible to reduce the number of parts.

1 is an overall perspective view of a battery pack of this embodiment; FIG. 1 is an overall perspective view of a battery pack of the present embodiment, showing only some battery cells and omitting other battery cells for convenience of explanation; FIG. FIG. 2 is a YZ sectional view of FIG. 1; FIG. 4 is an enlarged view of a portion of region α in FIG. 3; 4 is an enlarged view of a portion of region β in FIG. 3; FIG. FIG. 4 is a cross-sectional view taken along the line AA of FIG. 3; 4 is a cross-sectional view taken along the line BB of FIG. 3; FIG. 4 is a cross-sectional view taken along line CC of FIG. 3; FIG. FIG. 8 is an enlarged view of a region γ in FIG. 7; It is a figure which shows a modification.

Embodiments of the battery pack of the present disclosure will be described below.

<About the overall outline of the battery pack>
As shown in FIG. 1 , the battery pack 1 of this embodiment has a battery stack 11 and a battery case 12 that houses the battery stack 11 . The battery stack 11 is an example of the "battery module" of the present disclosure, and the battery case 12 is an example of the "case member" of the present disclosure.

The battery stack 11 is composed of a plurality of rectangular battery cells 21 stacked in the X direction shown in FIG. In this embodiment, two battery stacks 11 are arranged side by side in the Y direction shown in FIG. In the following description, the XYZ axes are defined as shown in FIG. 1 for convenience of description.

Each battery cell 21 included in the battery stack 11 has two electrode terminals 32 on its upper surface 31 . One of the two electrode terminals 32 is a positive terminal and the other is a negative terminal.

As shown in FIG. 3 , the battery cell 21 is fitted in the resin frame member 22 . The resin frame member 22 includes a bottom portion 41 , a first side wall portion 42 and a second side wall portion 43 . The bottom portion 41 holds the bottom portion of the battery cell 21 . In addition, the first side wall portion 42 and the second side wall portion 43 extend from both ends of the bottom surface portion 41 in the width direction (Y direction, left and right direction) of the battery pack 1 to the height direction (Z direction, upward direction) of the battery pack 1 . ) is formed so as to extend toward the The first side wall portion 42 and the second side wall portion 43 hold both side portions of the battery cell 21 .

As shown in FIG. 1, an end plate 13, which is a plate-like member, is attached to one end of the battery stack 11 in the stacking direction (that is, the end opposite to the end wall 52 described later). there is The end plate 13 is originally separate from the extruded battery case 12 and is attached later. Also, the end plate 13 is formed as an extruded material.

The battery case 12 is a box-shaped extruded aluminum member that is open at the top, and includes a case body 51 and end walls 52 .

The case main body 51 includes a bottom portion 53 , a first side wall portion 54 and a second side wall portion 55 . The bottom portion 53 is positioned below the battery stack 11 configured by stacking a plurality of battery cells 21 in the thickness direction. The first side wall portion 54 and the second side wall portion 55 are positioned on both sides of the battery stack 11 (that is, on both sides in the width direction (Y direction, left and right direction) of the battery pack 1). First side wall portion 54 and second side wall portion 55 are formed to extend in the height direction of battery pack 1 from both end portions of bottom surface portion 53 in the width direction of battery pack 1 .

The end wall 52 is arranged at one end of the battery stack 11 in the stacking direction (that is, the end opposite to the end plate 13 ). The end wall 52 is formed in a rectangular plate shape and is joined to the case body 51 by friction welding or welding.

Such a battery case 12 has two slot portions 57 which are storage spaces for the battery stack 11 and which are surrounded by the bottom portion 53 , the end wall 52 , the first side wall portion 54 and the second side wall portion 55 . I have.

The end of the battery case 12 opposite to the end wall 52 in the stacking direction of the battery stack 11 (that is, the end plate 13 side) is open. In addition, the battery pack 1 is appropriately attached with a cover member or the like for covering the upper portion depending on the scene in which the battery pack 1 is actually used.

<Positioning of battery cells (battery stacks)>
As shown in FIGS. 1 to 3, in the present embodiment, the first side wall portion 54 and the second side wall portion 55 of the battery case 12 each have a height direction of the individual battery cells 21 included in the battery stack 11. A groove portion 56 that regulates the position is formed along the stacking direction of the battery stack 11 . In addition, the groove portion 56 is an example of the “height restriction shape portion” of the present disclosure.

Further, as shown in FIG. 3 , the resin frame member 22 in which the battery cells 21 are fitted has a first side wall portion 42 and a second side wall portion 43 at the upper end portions thereof, which are restricted by the groove portion 56 of the battery case 12 . A flange portion 44 and a second flange portion 45 are provided. The first collar portion 44 is formed to extend from the first side wall portion 42 toward the inside and outside of the battery cell 21 . Also, the second flange portion 45 is formed to extend from the second side wall portion 43 toward the inside and outside of the battery cell 21 . The first collar portion 44 is an example of the "first height-restricted portion" in the present disclosure, and the second collar portion 45 is an example of the "second height-restricted portion" in the present disclosure.

Then, as shown in FIG. 4 , the first flange portion 44 is arranged such that the lower surface 71 (that is, the lower surface outside the battery cell 21 ) is in contact with the lower surface 73 of the groove portion 56 of the battery case 12 . embedded inside. Furthermore, the first flange portion 44 is arranged on the upper surface 31 of the battery cell 21 so that the lower surface 71 (that is, the lower surface inside the battery cell 21 ) is in contact with the upper surface 31 of the battery cell 21 .

Similarly, the second collar portion 45 is fitted inside the groove portion 56 so that the lower surface 71 thereof contacts the lower surface 73 of the groove portion 56 of the battery case 12 . Furthermore, the second flange portion 45 is arranged on the upper surface 31 of the battery cell 21 such that the lower surface 71 thereof is in contact with the upper surface 31 of the battery cell 21 .

In this manner, the battery cell 21 is positioned in the height direction with respect to the battery case 12 via the resin frame member 22 . As a result, variations in the position of the upper surface 31 of the battery cell 21 in the height direction can be minimized. Therefore, it is possible to stably connect the bus bar to the electrode terminal 32 provided on the upper surface 31 of the battery cell 21 .

Further, as shown in FIG. 2 , in the present embodiment, the bottom surface portion 53 of the battery case 12 has a plurality of alignment groove portions 58 that regulate the positions of the individual battery cells 21 included in the battery stack 11 in the width direction. , along the stacking direction of the battery stack 11 . Two alignment grooves 58 are formed for each slot 57 . It should be noted that the alignment groove portion 58 is an example of the "position restricting shape portion" of the present disclosure.

As shown in FIG. 5 , the alignment groove portion 58 has a bottom portion 81 and side portions 82 . The side surface portion 82 is formed in a tapered shape so as to enter the inside of the groove shape of the alignment groove portion 58 as it goes upward from the bottom surface portion 81 side (that is, the opening side of the groove shape of the alignment groove portion 58). It is

Further, as shown in FIG. 3 , the resin frame member 22 in which the battery cells 21 are fitted has, on its bottom surface portion 41 , alignment protrusions 46 that are restricted by the alignment grooves 58 of the battery case 12 . Two alignment protrusions 46 are formed for one resin frame member 22 . It should be noted that the alignment convex portion 46 is an example of the “position-restricted portion” of the present disclosure.

As shown in FIG. 5 , the alignment convex portion 46 has a bottom portion 91 and side portions 92 . The side surface portion 92 is formed in a tapered shape so as to enter the inside of the alignment convex portion 46 as it goes upward from the bottom surface portion 91 side.

Regarding the alignment groove 58 of the battery case 12 and the alignment protrusion 46 of the battery cell 21, the alignment protrusion 46 is fitted inside the alignment groove 58, and the side surface 92 of the alignment protrusion 46 and the side surface of the alignment groove 58 are fitted. 82 are in contact with each other.

In this manner, the battery cell 21 is positioned in the width direction with respect to the battery case 12 via the resin frame member 22 .

In this embodiment, the battery cells 21 are positioned with respect to the battery case 12 in the height direction and the width direction of the battery pack 1 as described above. That is, the contact point between the first flange portion 44 and the second flange portion 45 of the resin frame member 22 and the groove portion 56 of the battery case 12 , the first flange portion 44 and the second flange portion 45 of the resin frame member 22 and the battery cell 21 and contact points between the alignment projections 46 of the resin frame member 22 and the alignment grooves 58 of the battery case 12 , the battery case 12 Positioning of the battery cell 21 with respect to is performed. Thereby, the battery stack 11 in which the plurality of battery cells 21 are stacked is positioned with respect to the battery case 12 in the height direction and the width direction of the battery pack 1 .

In this way, the battery case 12 functions as a case for housing the battery stack 11 and as a jig for positioning the battery stack 11 in the height direction and width direction of the battery pack 1 . In particular, since the battery case 12 is made of extruded aluminum, the shape and positional accuracy of the grooves 56 and alignment grooves 58 can be increased, so that the battery stack 11 can be positioned with high accuracy.

In this way, in the present embodiment, the alignment protrusions 46 of the battery cells 21 are regulated by the alignment grooves 48 of the battery case 12, and the first flanges 44 and the first flanges 44 and 44 of the resin frame member 22 in which the battery cells 21 are fitted. The second flange portion 45 is restricted by the groove portion 56 of the battery case 12 .

Accordingly, the attachment of the battery cell 21 to the battery case 12 and the positioning of the battery cell 21 with respect to the battery case 12 can be performed without using special parts for attachment. Therefore, it is possible to attach the battery stack 11 formed by stacking a plurality of battery cells 21 in the thickness direction to the battery case 12 and to position the battery stack 11 with respect to the battery case 12 while reducing the number of parts of the battery pack 1 . can.

In addition, since the number of parts of the battery pack 1 is reduced, the accumulation of tolerances of each part is reduced. Therefore, for example, the height accuracy of the electrode terminals 32 of the battery cells 21 (that is, the accuracy in the height direction of the battery pack 1) is improved, and a bus bar (not shown) can be stably joined to the electrode terminals 32. . In particular, in the present embodiment, the first flange portion 44 and the second flange portion 45 of the resin frame member 22 in which the battery cell 21 is fitted are regulated by the groove portion 56 of the battery case 12, so that the electrode terminal 32 of the battery cell 21 is Height accuracy is improved. Moreover, by reducing the number of parts of the battery pack 1, the battery pack 1 can be made smaller, and the manufacturing process of the battery pack 1 can be simplified and the manufacturing cost can be reduced.

Further, in the present embodiment, since the alignment convex portion 46, the first flange portion 44, and the second flange portion 45 are integrated into the resin frame member 22, the number of parts per battery pack can be reduced more effectively.

<About battery cell cooling>
As shown in FIG. 3, in the present embodiment, one side surface 23 of the battery stack 11 and a portion of the first side wall portion 54 of the battery case 12 other than the groove portion 56 (that is, a portion below the groove portion 56) There is a gap 111 between.

Also, between the other side surface 24 of the battery stack 11 (that is, the other side surface) and the portion of the second side wall portion 55 of the battery case 12 other than the groove portion 56 (that is, the portion below the groove portion 56) , there is a gap 112 .

Furthermore, there is a gap 113 between the bottom surface 25 of the battery stack 11 and the portion of the bottom surface portion 53 of the battery case 12 other than the alignment grooves 58 (that is, the portion between the two alignment grooves 58).

The gap 111, the gap 112, and the gap 113 communicate with each other. As a result, as shown in FIGS. 6 to 8, the cooling air can flow into the gap 111 and the gap 112 from the external duct. As a result, the cooling air flows through the gaps 111 and 112 and between the adjacent battery cells 21 , and then flows outside the battery pack 1 through the gaps 113 . Therefore, the battery cells 21 can be cooled, and exhaust heat discharged from the battery cells 21 can be discharged to the outside of the battery pack 1 . Alternatively, the cooling air may flow from the external duct into the gap 113 so that the cooling air flows outside the battery pack 1 from the gaps 111 and 112 . 7, the cooling air may be flown into the gap 111 and the gap 112 from the end wall 52 side, as indicated by dotted arrows.

In this way, in the present embodiment, the cooling air is caused to flow inside the battery pack 1 through the gaps 111, 112, and 113 formed between the battery stack 11 and the battery case 12. Individual battery cells 21 included in the stack 11 can be cooled.

In addition, as shown in FIGS. 1 and 7, in the present embodiment, the end plate 13 has openings 121 for ventilating the gaps 111 and 112 with the outside. The end plate 13 includes a rigid member 101 and a resin member 102 located on the inner surface side of the rigid member 101 (that is, the side on which the battery stack 11 is arranged).

The rigid member 101 is made of metal (for example, aluminum). The rigid member 101 is joined to the case body 51 of the battery case 12 by friction welding or welding, or by using bolts.

The resin member 102 is made of resin (for example, PP (polypropylene)). In this embodiment, the resin member 102 has a lip portion 103 that is in close contact with the case body 51 of the battery case 12 .

In this manner, since the lip portion 103 of the resin member 102 of the end plate 13 is in close contact with the case body 51 of the battery case 12, the cooling air flowing through the gap 111 and the gap 112 inside the battery pack 1 can flow into the battery pack. 1 can be prevented from escaping to the outside. Therefore, the battery cells 21 can be efficiently cooled by the cooling air.

<About the fastening point of the battery pack to the device>
As shown in FIG. 1, the battery stack 11 is accommodated in the battery case 12 while being compressed in the stacking direction. As shown in FIG. 6, in the present embodiment, devices (not shown, for example, a vehicle ) are provided. At this fastening point 114 , as shown in FIG. 3 , the battery pack 1 is fastened to the device with a bolt 115 via a plate member 116 that is fastened to the battery case 12 with a bolt 115 . In this embodiment, three fastening points 114 are provided in the stacking direction of the battery stack 11 .

As a result, the binding load in the stacking direction of the battery stack 11 acting on the end wall 52 is less likely to act on the region inside the stacking direction of the battery stack 11 than the end wall 52 , and thus acts on the fastening portion 114 to the device. becomes difficult. Therefore, the battery pack 1 can be stably fastened to the device.

<About Modifications>
As a modification, the battery pack 1 may have an L-shaped guard 117 for collision absorption, as indicated by the dotted line in FIG.

As another modification, as shown in FIG. 10, the battery pack 1 may be split left and right. As a result, the battery stack 11 can be easily accommodated in the battery case 12, and the handling of the battery stack 11 is improved.

It should be noted that the above-described embodiment is merely an example and does not limit the present disclosure in any way, and of course various improvements and modifications are possible without departing from the gist of the present disclosure.

1 Battery pack 11 Battery stack 12 Battery case 13 End plate 21 Battery cell 22 Resin frame member 23 One side surface 24 Other side surface 25 Bottom surface 41 Bottom surface portion 42 First side wall portion 43 Second side wall portion 44 First collar portion 45 Second Collar 46 Alignment protrusion 51 Case main body 52 End wall 53 Bottom surface 54 First sidewall 55 Second sidewall 56 Groove 58 Alignment groove 101 Rigid member 102 Resin member 103 Lip 111 Gap 112 Gap 113 Gap 114 Fastening part

Claims (5)

A battery pack in which a plurality of battery cells are stacked and housed in a case member,
The case member is
a bottom portion positioned below a battery module formed by stacking a plurality of battery cells in the thickness direction;
having a first side wall portion and a second side wall portion located on both sides of the battery module;
A plurality of position regulating shape portions for regulating positions of individual battery cells included in the battery module in the width direction are formed on the bottom surface portion along the stacking direction of the battery module,
Each of the first side wall portion and the second side wall portion has a height regulating shape portion formed along the stacking direction of the battery module for regulating the height direction position of each battery cell included in the battery module. has been
Each battery cell included in the battery module is
a plurality of position regulated portions regulated by the position regulating shape portion;
A battery pack having a first height-restricted portion and a second height-restricted portion that are restricted by the height restriction shape portion. The battery pack according to claim 1,
Each individual battery cell included in the battery module is fitted in a resin frame member,
The battery pack, wherein the position-restricted portion, the first height-restricted portion, and the second height-restricted portion are all formed in the resin frame member. The battery pack according to claim 1 or 2,
there is a gap between the bottom surface of the battery module and a portion of the bottom surface portion of the case member other than the position regulating shape portion;
there is a gap between one side surface of the battery module and a portion of the first side wall portion of the case member other than the height restricting shape portion;
A battery pack having a gap between the other side surface of the battery module and a portion of the second side wall portion of the case member other than the height restricting shape portion. The battery pack according to claim 3,
having an end plate attached to one end in the stacking direction of the battery module and allowing each of the gaps to communicate with the outside;
The end plate has a rigid member and a resin member located on the inner surface side of the rigid member,
The battery pack, wherein the resin member has a lip portion that is in close contact with the case member. The battery pack according to any one of claims 1 to 4,
The case member has an end wall located on one end side in the stacking direction of the battery modules,
The battery module is accommodated in the case member in a state of being compressed in the stacking direction,
A battery pack in which fastening points to a device are provided at a plurality of locations in a region on the inner side of the end wall in the stacking direction of the battery modules on the bottom surface portion.

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