Battery pack

Abstract

To provide a battery pack that can stably flow cooling air in a cooling air path formed between a cell case and a spacer.SOLUTION: In a battery pack 1 according to an aspect of the present disclosure, a cooling air path 31 through which cooling air flows is formed between a cell case 21 of a battery cell 11 and a spacer 12. In the cell case 21, a pressurized region 41 that is pressurized by the spacer 12 and a non-pressurized region 42 that is not pressurized by the spacer 12 exist. A lower non-pressurized region 42A is formed as the non-pressurized region 42 below the pressurized region 41 in the height direction of the battery cell 11, and a thickness T2A in the arrangement direction of the battery cell 11 in the lower non-pressurized region 42A is formed smaller than a thickness T1 in the arrangement direction of the battery cell 11 in the pressurized region 41.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a battery pack.

Background Art

[0002] As a conventional technology related to a battery pack, Patent Document 1 discloses that, in a battery pack in which a plurality of battery cells and spacers are alternately stacked, ribs for forming a cooling air path are formed on the surface of the spacer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the battery pack disclosed in Patent Document 1, a restraining force is applied in the stacking direction of the battery cells and the spacers, whereby the battery cells and the ribs of the spacers are brought into close contact with each other, and the battery cells are pressed by the spacers. Here, the ribs of the spacer are arranged only on the portion of the surface of the spacer corresponding to the electrode body. Therefore, there is a risk that the remaining collapse of the cell case occurs at the portion corresponding to the inlet and outlet of the cooling air path where the ribs are not arranged, and the cooling air path may be obstructed. Then, the cooling air cannot flow stably in the cooling air path, and the cooling performance deteriorates.

[0005] 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 stably flowing cooling air in a cooling air path formed between a cell case and a spacer.

Means for Solving the Problems

[0006] One aspect of the present disclosure made to solve the above problems is a battery pack having a plurality of battery cells arranged therein and spacers disposed between adjacent battery cells. A cooling air passage through which cooling air flows is formed between the cell case of the battery cell and the spacer. In the cell case, there are a pressurized portion pressurized by the spacer and a non-pressurized portion not pressurized by the spacer. A lower non-pressurized portion is formed as the non-pressurized portion below the pressurized portion in the height direction of the battery cell. The thickness of the battery cell in the arrangement direction in the lower non-pressurized portion is formed to be smaller than the thickness of the battery cell in the arrangement direction in the pressurized portion.

[0007] According to this aspect, there is no remaining collapse of the cell case due to not being pressurized by the spacer at the lower non-pressurized portion. Therefore, in the cooling air passage, the passage inlet at the lower side in the height direction of the battery cell is not narrowed or blocked by the lower non-pressurized portion. Thus, when cooling air is introduced from the passage inlet, the flow of the cooling air is not obstructed by the lower non-pressurized portion. Therefore, the cooling air can flow stably in the cooling air passage, and the cooling performance of the battery cell by the cooling air is improved.

[0008] In the above aspect, widthwise non-pressurized portions are formed as the non-pressurized portions on both sides in the width direction of the battery cell with respect to the pressurized portion. The thickness of the battery cell in the arrangement direction in the widthwise non-pressurized portion is formed to be smaller than the thickness of the battery cell in the arrangement direction in the pressurized portion and is formed to be constant in the height direction of the battery cell, which is preferable.

[0009] According to this aspect, there is no remaining collapse of the cell case due to not being pressurized by the spacer at the non-pressurized portion in the width direction. Therefore, in the cooling air path, the path outlets on both sides in the width direction of the battery cell are not narrowed or blocked by the non-pressurized portion in the width direction. Accordingly, when the cooling air flows out from the path outlet, the flow of the cooling air is not obstructed by the non-pressurized portion in the width direction. Thus, the cooling air can be stably flowed in the cooling air path more effectively, and the cooling performance of the battery cell by the cooling air is improved.

[0010] Also, the thickness of the non-pressurized portion in the width direction is formed to be constant in the height direction of the battery cell. And thereby, the side surfaces of the non-pressurized portion in the width direction are formed in parallel along the height direction of the battery cell. Therefore, at the path outlet, the cooling air can be flowed evenly in the height direction of the battery cell, and the cooling performance of the battery cell by the cooling air is further improved.

[0011] Another aspect of the present disclosure made to solve the above problems is a battery pack having a plurality of battery cells to be arranged and a spacer disposed between the adjacent battery cells. A cooling air path through which cooling air flows is formed between the cell case of the battery cell and the spacer. In the cell case, there are a pressurized portion pressurized by the spacer and a non-pressurized portion not pressurized by the spacer. On both sides in the width direction of the battery cell with respect to the pressurized portion, a non-pressurized portion in the width direction is formed as the non-pressurized portion. The thickness of the battery cell in the arrangement direction in the non-pressurized portion in the width direction is formed to be smaller than the thickness of the battery cell in the arrangement direction in the pressurized portion, and is formed to be constant in the height direction of the battery cell.

[0012] According to this aspect, there is no remaining crushing of the cell case due to not being pressed by the spacer at the non-pressurized portion in the width direction. Therefore, in the cooling air path, the path inlet on one side in the width direction of the battery cell and the path outlet on the other side in the width direction of the battery cell are not narrowed or blocked by the non-pressurized portion in the width direction. Accordingly, when the cooling air is flowed in from the path inlet and flowed out from the path outlet, the flow of the cooling air is not obstructed by the non-pressurized portion in the width direction. Therefore, since the cooling air can be stably flowed in the cooling air path, the cooling performance of the battery cell by the cooling air is improved.

[0013] Further, the thickness of the non-pressurized portion in the width direction is formed to be constant in the height direction of the battery cell. And thereby, the side surface of the non-pressurized portion in the width direction is formed in parallel along the height direction of the battery cell. Therefore, in the path inlet and the path outlet, the cooling air can be evenly flowed in the height direction of the battery cell, so that the cooling performance of the battery cell by the cooling air is further improved.

[0014] In the above aspect, it is preferable that the thickness of the battery cell in the arrangement direction in the non-pressurized portion is formed to become smaller as it is away from the pressurized portion.

[0015] According to this aspect, since the cooling air easily flows along the non-pressurized portion, the cooling air can be more effectively and stably flowed in the cooling air path.

Advantages of the Invention

[0016] According to the assembled battery of the present disclosure, the cooling air can be stably flowed in the cooling air path formed between the cell case and the spacer.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

[0018] Hereinafter, embodiments of the assembled battery of the present disclosure will be described.

[0019] 〔First Embodiment〕 First, the first embodiment will be described.

[0020] As shown in FIG. 1, the assembled battery 1 of the present embodiment includes battery cells 11 and spacers 12. The battery cells 11 are rectangular batteries, and a plurality of battery cells 11 are arranged in the X direction shown in FIG. 1. And, spacers 12 are arranged between adjacent battery cells 11. For the sake of convenience of explanation, XYZ directions orthogonal to each other are defined as shown in FIG. 1.

[0021] As shown in FIGS. 2, 3(a), and 4(a), a cooling air path 31 through which cooling air for cooling the battery cells 11 flows is formed between the cell case 21 of the battery cells 11 and the spacers 12.

[0022] In this embodiment, as shown in FIG. 2, the cooling air flows into the cooling air path 31 from the path inlet 32 located below the battery cell 11 in the height direction (Z direction), and then is divided and flows on both sides in the width direction (Y direction) of the battery cell 11 (that is, the left side and the right side in FIG. 2), and flows out from the path outlets 33 on both sides in the width direction of the battery cell 11.

[0023] Also, as shown in FIGS. 3(a) and 4(a), a part of the cell case 21 (specifically, the part of the electrode body 22) is pressurized by the spacer 12 (specifically, the rib 12a of the spacer 12). Therefore, in the cell case 21, there are a pressurized portion 41 pressurized by the spacer 12 and a non-pressurized portion 42 not pressurized by the spacer 12. FIGS. 3(b) and 4(b) show the states of the cell case 21 before being pressurized by the spacer 12, respectively.

[0024] As shown in FIG. 3(a), when the pressurized range by the spacer 12 in the cell case 21 is defined as the pressurized range α, a lower non-pressurized portion 42A is formed as a non-pressurized portion 42 below the battery cell 11 at the portion corresponding to this pressurized range α.

[0025] Here, in the prior art, as shown in FIG. 7(a), the thickness T0A in the arrangement direction (X direction) of the battery cell 11 in the lower non-pressurized portion 42A was formed to be larger than the thickness T1 in the arrangement direction of the battery cell 11 in the pressurized portion 41.

[0026] That is, as shown in FIG. 7(b), in the state before the cell case 21 is pressurized by the spacer 12, in the prior art, the thickness of the cell case 21 was constant in the height direction of the battery cell 11. As a result, in the state after the cell case 21 is pressurized by the spacer 12, as shown in FIG. 7(a), while the pressurized portion 41 is pressurized and crushed by the spacer 12, there remains a crush of the cell case 21 due to the non-pressurization by the spacer 12 in the lower non-pressurized portion 42A.

[0027] As a result, in the prior art, in the cooling air path 31, the path inlet 32 is narrowed or blocked by the lower non-pressurized portion 42A, so when cooling air is introduced from the path inlet 32, the flow of the cooling air is obstructed by the lower non-pressurized portion 42A.

[0028] In contrast, in the present embodiment, as shown in FIG. 3(a), the thickness T2A in the arrangement direction of the battery cells 11 in the lower non-pressurized portion 42A is formed to be smaller than the thickness T1 of the pressurized portion 41.

[0029] That is, as shown in FIG. 3(b), in the state before the cell case 21 is pressurized by the spacer 12, in the present embodiment, regarding the thickness of the cell case 21, the portion that becomes the lower non-pressurized portion 42A is made smaller than the portion that becomes the pressurized portion 41. As a result, in the state after the cell case 21 is pressurized by the spacer 12, as shown in FIG. 3(a), while the pressurized portion 41 is pressurized and crushed by the spacer 12, there is no remaining crush of the cell case 21 due to the fact that the lower non-pressurized portion 42A is not pressurized by the spacer 12.

[0030] As a result, in the cooling air path 31, the path inlet 32 is not narrowed or blocked by the lower non-pressurized portion 42A. Therefore, when cooling air is introduced from the path inlet 32, the flow of the cooling air is not obstructed by the lower non-pressurized portion 42A. Accordingly, the cooling air can flow stably in the cooling air path 31, so the cooling performance of the battery cells 11 by the cooling air is improved.

[0031] Also, as shown in FIG. 4(a), in the present embodiment, widthwise non-pressurized portions 42B are formed as non-pressurized portions 42 on both sides in the width direction of the battery cells 11 with respect to the pressurized portion 41.

[0032] Here, in the prior art, as shown in FIG. 8(a), the thickness T0B in the arrangement direction of the battery cells 11 in the widthwise non-pressurized portion 42B was formed to be larger than the thickness T1 of the pressurized portion 41.

[0033] That is, as shown in FIG. 8(b), in the state before the cell case 21 is pressurized by the spacer 12, in the prior art, the thickness of the cell case 21 was constant across the width direction of the battery cell 11. As a result, in the state after the cell case 21 is pressurized by the spacer 12, as shown in FIG. 8(a), while the pressurized portion 41 is pressurized and crushed by the spacer 12, there remains a crush of the cell case 21 due to not being pressurized by the spacer 12 at the non-pressurized portion 42B in the width direction.

[0034] And thus, in the prior art, in the cooling air path 31, the path outlet 33 is narrowed or blocked by the non-pressurized portion 42B in the width direction. Therefore, when the cooling air flows out from the path outlet 33, the flow of the cooling air is inhibited by the non-pressurized portion 42B in the width direction.

[0035] In contrast, in the present embodiment, as shown in FIG. 4(a), the thickness T2B in the arrangement direction of the battery cells 11 at the non-pressurized portion 42B in the width direction is formed to be smaller than the thickness T1 of the pressurized portion 41.

[0036] That is, as shown in FIG. 4(b), in the state before the cell case 21 is pressurized by the spacer 12, in the present embodiment, regarding the thickness of the cell case 21, the portion that becomes the non-pressurized portion 42B in the width direction is made smaller than the portion that becomes the pressurized portion 41. As a result, in the state after the cell case 21 is pressurized by the spacer 12, as shown in FIG. 4(a), while the pressurized portion 41 is pressurized and crushed by the spacer 12, there is no remaining crush of the cell case 21 due to not being pressurized by the spacer 12 at the non-pressurized portion 42B in the width direction.

[0037] And thus, in the cooling air path 31, the path outlet 33 is not narrowed or blocked by the non-pressurized portion 42B in the width direction. Therefore, when the cooling air flows out from the path outlet 33, the flow of the cooling air is not inhibited by the non-pressurized portion 42B in the width direction. Accordingly, the cooling air can flow stably in the cooling air path 31 more effectively, so that the cooling performance of the battery cells 11 by the cooling air is improved.

[0038] Also, both the B-B cross-section and the C-C cross-section in FIG. 2 are represented as shown in FIG. 4(a), and the thickness T2B of the non-pressurized portion 42B in the width direction is formed to be constant in the height direction of the battery cell 11. As a result, the side surfaces of the non-pressurized portion 42B in the width direction are formed parallel along the height direction of the battery cell 11. Therefore, at the path outlet 33, the cooling air can flow evenly in the height direction of the battery cell 11, so that the cooling performance of the battery cell 11 by the cooling air is further improved.

[0039] Also, as shown in FIGS. 3(a) and 4(a), the thickness T2A of the lower non-pressurized portion 42A and the thickness T2B of the non-pressurized portion 42B in the width direction are formed to decrease as they are farther from the pressurized portion 41, and the side surfaces of the lower non-pressurized portion 42A and the non-pressurized portion 42B in the width direction are formed in a tapered shape. As a result, the cooling air easily flows along the lower non-pressurized portion 42A and the non-pressurized portion 42B in the width direction, so that the cooling air can be stably flowed in the cooling air path 31 more effectively.

[0040] Also, since the thickness T2A of the lower non-pressurized portion 42A is formed small, as shown in FIG. 5, the surplus liquid (liquid with a height H) required for the electrode body 22 to be immersed in the electrode liquid can be less than that in the prior art shown in FIG. 9, so that cost reduction can be achieved.

[0041] 〔Second Embodiment〕 Next, the main features of the second embodiment will be mainly described.

[0042] In this embodiment, as a difference from the first embodiment, as shown in FIG. 6, the cooling air flows into the cooling air path 31 from the path inlet 34 on the left side in the width direction of the battery cell 11, and then, after flowing in the width direction of the battery cell 11, flows out from the path outlet 35 on the right side in the width direction of the battery cell 11.

[0043] And in this embodiment, as shown in Fig. 4(a), similar to the first embodiment, on both sides in the width direction of the battery cell 11 with respect to the pressurized portion 41, width-direction non-pressurized portions 42B are formed as non-pressurized portions 42. And the thickness T2B of the width-direction non-pressurized portion 42B is formed to be smaller than the thickness T1 of the pressurized portion 41. Also, the thickness T2B of the width-direction non-pressurized portion 42B is formed to be constant in the height direction of the battery cell 11.

[0044] Also for such a second embodiment, similar to the first embodiment, the cooling air can flow stably in the cooling air path 31.

[0045] That is, there is no remaining collapse of the cell case 21 due to not being pressurized by the spacer 12 at the width-direction non-pressurized portion 42B. Therefore, in the cooling air path 31, the path inlet 34 and the path outlet 35 are not narrowed or blocked by the width-direction non-pressurized portion 42B. Thus, when flowing in the cooling air from the path inlet 34 and flowing out the cooling air from the path outlet 35, the flow of the cooling air is not inhibited by the width-direction non-pressurized portion 42B. Therefore, since the cooling air can flow stably in the cooling air path 31, the cooling performance of the battery cell 11 by the cooling air is improved.

[0046] Also, the thickness T2B of the width-direction non-pressurized portion 42B is formed to be constant in the height direction of the battery cell 11. And thereby, the side surfaces of the width-direction non-pressurized portion 42B are formed in parallel along the height direction of the battery cell 11. Therefore, in the path inlet 34 and the path outlet 35, the cooling air can flow evenly in the height direction of the battery cell 11, so the cooling performance of the battery cell 11 by the cooling air is further improved.

[0047] Note that the above-described embodiments are merely examples and do not limit the present disclosure at all. Of course, various improvements and modifications are possible without departing from the gist thereof.

Explanation of Reference Numerals

[0048] Battery pack 11 Battery cell 12 Spacer 12a Rib 21 Cell Case 22 Electrode Body 31 Cooling Air Path 32 Path Inlet 33 Path Outlet 34 Path Inlet 35 Path Outlet 41 Pressurized Portion 42 Non - Pressurized Portion 42A Lower Non - Pressurized Portion 42B Width - Direction Non - Pressurized Portion α Pressurization Range T0A, T0B, T1, T2A, T2B Thickness H Height

Claims

1. A plurality of battery cells to be arranged, A spacer disposed between adjacent battery cells, In a battery pack having, A cooling air passage through which cooling air flows is formed between the cell case of the battery cell and the spacer, In the cell case, there are a pressurized portion pressurized by the spacer and a non-pressurized portion not pressurized by the spacer, A lower non-pressurized portion is formed as the non-pressurized portion below the pressurized portion in the height direction of the battery cell, The thickness in the arrangement direction of the battery cell in the lower non-pressurized portion is formed smaller than the thickness in the arrangement direction of the battery cell in the pressurized portion, A battery pack characterized by the above.

2. In the battery pack according to Claim 1, Width direction non-pressurized portions are formed as the non-pressurized portions on both sides in the width direction of the battery cell with respect to the pressurized portion, The thickness in the arrangement direction of the battery cell in the width direction non-pressurized portion is formed smaller than the thickness in the arrangement direction of the battery cell in the pressurized portion and is formed constant in the height direction of the battery cell, A battery pack characterized by the above.

3. A plurality of battery cells to be arranged, A spacer disposed between adjacent battery cells, In a battery pack having, A cooling air passage through which cooling air flows is formed between the cell case of the battery cell and the spacer, In the cell case, there are a pressurized portion pressurized by the spacer and a non-pressurized portion not pressurized by the spacer, Width direction non-pressurized portions are formed as the non-pressurized portions on both sides in the width direction of the battery cell with respect to the pressurized portion, The thickness in the arrangement direction of the battery cell in the width direction non-pressurized portion is formed smaller than the thickness in the arrangement direction of the battery cell in the pressurized portion and is formed constant in the height direction of the battery cell, A battery pack characterized by the above.

4. In the battery pack according to any one of Claims 1 to 3, The thickness in the arrangement direction of the battery cell in the non-pressurized portion is formed to become smaller as it is farther from the pressurized portion, A battery pack characterized by the above.

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