Battery cell group and battery pack

Abstract

The utility model provides a battery cell group and battery pack, the battery cell group includes at least one battery cell and cooling member, each battery cell has the first part that is equipped with the pole and is connected with the side part of the first part, the cooling member is used for cooling at least one battery cell and includes the first plate and the side plate that is connected with one side of the first plate, the first plate abuts against the first part of the at least one battery cell, and the side plate abuts against the side part of the at least one battery cell. According to the battery cell group provided by the utility model, the first plate and the side plate are respectively connected to the first part and the side part of the battery cell in a heat conduction manner, so that the cooling plate can cool the part with higher temperature of the battery cell group in a fast charging state, and the risk of local overheating of the battery cell group can be effectively reduced.

Description

Technical Field

[0001] This utility model relates to the field of batteries, specifically to a battery cell assembly and battery pack. Background Technology

[0002] Currently, the cooling technology for battery cells in electric vehicles and other battery-powered devices typically involves installing a cooling device at the bottom of the cell assembly to control its temperature. While this method is effective in reducing the overall battery temperature in most cases, its effectiveness is less than ideal when the cell assembly is in a fast-charging state. Experimental verification shows that when the cell assembly is fast-charging, the hottest areas inside the cell are usually near the tabs. When the tabs are not located at the bottom of the cell, the aforementioned cooling method cannot effectively cool the cell assembly. Utility Model Content

[0003] The present invention provides a cell assembly and battery pack to solve the problem of unsatisfactory cooling effect of cell assemblies in related technologies.

[0004] In a first aspect, embodiments of the present invention provide a battery cell assembly, comprising: at least one battery cell, each battery cell having a first portion and a side portion connected to one side of the first portion, each battery cell including an electrode post disposed in the first portion; and a cooling member for cooling at least one battery cell, including a first plate and a side plate connected to one side of the first plate; wherein the first plate abuts against the first portion of at least one battery cell, and the side plate abuts against the side portion of at least one battery cell.

[0005] In one embodiment, 0.8 ≤ L1 / d ≤ 1; where L1 is the dimension of the first plate in the first direction, d is the distance between the pole post and the side plate in the first direction, and the first direction is the direction in which the first plate points to the pole post.

[0006] In one embodiment, 0.55 ≤ L2 / h ≤ 0.65; where h is the height of at least one cell and L2 is the dimension of the side plate in the height direction of at least one cell.

[0007] In one embodiment, each battery cell includes a battery cell body and an insulating film covering the outer surface of the battery cell body. The insulating film has a first window and a second window. A first plate abuts against at least one battery cell body through the first window to abut against the first part of at least one battery cell, and a side plate abuts against at least one battery cell body through the second window to abut against the side part of at least one battery cell.

[0008] In one embodiment, 0.8≤L1 / d≤1, 0.6≤L3 / d≤0.8; where L1 is the dimension of the first plate in the first direction, L3 is the dimension of the first window portion in the first direction, d is the distance between the pole post and the side plate in the first direction, and the first direction is the direction in which the first plate points to the pole post.

[0009] In one embodiment, 0.5 ≤ W1 / W ≤ 0.8; where W is the size of the cell in the second direction, W1 is the size of the first window portion in the second direction, and the second direction is the arrangement direction of the plurality of cells.

[0010] In one embodiment, 0.6 ≤ L3 / L1 ≤ 1; where L1 is the dimension of the first plate in the first direction, and L3 is the dimension of the first window portion in the first direction.

[0011] In one embodiment, 0.55≤L2 / h≤0.65, 0.5≤L4 / h≤0.6; where L2 is the dimension of the side plate in the height direction of at least one cell, h is the height of at least one cell, and L4 is the dimension of the second window portion in the height direction of at least one cell.

[0012] In one embodiment, 0.5 ≤ W2 / W ≤ 0.7; where W is the width of the battery cell and W2 is the dimension of the second window portion in the second direction.

[0013] Secondly, embodiments of the present invention provide a battery pack that includes the battery cell assembly of the first aspect.

[0014] This invention provides a battery cell assembly and a battery pack. The battery cell assembly includes at least one battery cell and a cooling component. Each battery cell has a first portion with terminals and a side portion connected to one side of the first portion. The cooling component is used to cool at least one battery cell and includes a first plate and a side plate connected to one side of the first plate. The first plate abuts against the first portion of at least one battery cell, and the side plate abuts against the side portion of at least one battery cell. The battery cell assembly provided by this invention, by thermally connecting the first plate and the side plate to the first portion and the side portion of the battery cell respectively, allows the cooling plate to cool the high-temperature areas of the battery cell assembly during fast charging, thereby effectively reducing the risk of localized overheating of the battery cell assembly. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the battery cell assembly provided in an embodiment of the present invention;

[0017] Figure 2 yes Figure 1 Exploded view;

[0018] Figure 3 yes Figure 1 Top view of the battery cell assembly;

[0019] Figure 4 yes Figure 3 Enlarged perspective view of section A;

[0020] Figure 5 yes Figure 1 Front view of a battery cell assembly;

[0021] Figure 6 yes Figure 2 A top view of multiple battery cells;

[0022] Figure 7 yes Figure 6 Enlarged perspective view of section B;

[0023] Figure 8 yes Figure 2 Side view of multiple battery cells;

[0024] Explanation of reference numerals in the attached figures:

[0025] 100, Cell assembly; 110, Cell; 120, Cooling component; 210, First part; 220, Side part; 230, Terminal post; 240, First plate; 250, Side plate; 260, Cell body; 270, Insulating film; 280, First window opening; 290, Second window opening. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of the present utility model and are not intended to limit the present utility model. In the present utility model, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0027] Experimental verification shows that when the battery cell assembly is in fast charging mode, the areas with higher internal temperatures are usually distributed at and near the battery tabs. The tabs of some cells (such as square cells) are usually located on the side of the cell and in the area where the terminal block meets the side. In related technologies, cooling components are usually located at the bottom of the battery cell assembly, so the above-mentioned cells cannot be effectively cooled.

[0028] To address the issue of unsatisfactory cooling performance of battery cell packs in the aforementioned related technologies, this utility model provides a battery cell pack 100, please refer to... Figure 1 , Figure 2 , Figure 1 This is a schematic diagram of the structure of the battery pack 100 provided in this embodiment of the utility model. Figure 2 yes Figure 1 The exploded view shows that the battery cell assembly 100 includes at least one battery cell 110 and a cooling element 120, which is used to cool the battery cell 110. Specifically, the battery cell 110 includes a first part 210 and a side part 220 connected to one side of the first part 210. The terminal post 230 of the battery cell 110 is disposed in the first part 210 of the battery cell 110, and the electrode tab (not shown in the figure) of the battery cell 110 is disposed in the first part 210 and the side part 220 and is electrically connected to the terminal post 230. The cooling component 120 includes a first plate 240 and a side plate 250 connected to one side of the first plate 240. The first plate 240 abuts against the first part 210 of the battery cell 110, and the side plate 250 abuts against the side part 220 of the battery cell 110, so that the first plate 240 and the side plate 250 are thermally connected to the first part 210 and the side part 220 of the battery cell 110, respectively, so as to cool the first part 210 and the side part 220 of the battery cell 110, respectively.

[0029] In this embodiment, by thermally connecting the first plate 240 and the side plate 250 to the first part 210 and the side part 220 of the battery cell 110 respectively, the cooling plate can cool the parts of the battery cell assembly 100 that have high temperature in the fast charging state, thereby effectively reducing the risk of local overheating of the battery cell assembly 100.

[0030] It should be noted that the cooling element 120 provided by this utility model dissipates heat from the battery cell 110 by circulating a cooling medium. The cooling channel for circulating the cooling medium can be implemented in various ways. For example, the inlet and outlet of the cooling medium can be located on the same side of the extending direction of the cooling element 120, or on different sides of the extending direction of the cooling element 120. In the embodiments provided by this utility model, the cooling channel can take different forms such as straight, curved, or spiral, and the width and height of the channel can also be adjusted according to cooling requirements. No specific limitation is placed on the cooling channel structure of the cooling element 120.

[0031] In the embodiments provided by this utility model, the direction in which the first plate 240 points to the pole post 230 or the direction in which the pole post 230 points to the first plate 240 is designated as the first direction, which can be referred to Figure 1 The X direction in the text specifies the arrangement direction of multiple battery cells 110 as the second direction, which can be referenced. Figure 1 In the Y direction, the height direction of cell 110 is designated as the third direction, which can be referred to Figure 1 The Z direction in the equation.

[0032] What is easy to understand is that it can be used as a reference. Figures 2 to 4 , Figure 3 yes Figure 1 Top view of the CNC chip pack 100 Figure 4 yes Figure 3 In the enlarged perspective view of section A, if the dimension L1 of the first plate 240 in the first direction is too short, it may result in poor heat dissipation of the first part 210 of the battery cell 110, causing the first part 210 to overheat, thereby affecting the service life and safety of the battery cell assembly 100. Conversely, if the dimension L1 of the first plate 240 in the first direction is too long, it may cause interference between the first plate 240 and the terminal post 230 of the battery cell 110 during assembly, thereby affecting the assembly efficiency of the battery cell assembly 100 or even preventing the installation of the cooling component 120.

[0033] In order to effectively solve the above problems and achieve a balance between the cooling efficiency of the cooling component 120 to the battery cell assembly 100 and the ease of assembly of the battery cell assembly 100, in some embodiments, the ratio of the dimension L1 of the first plate 240 in the first direction to the distance d between the pole post 230 and the side plate 250 in the first direction is set in the range of 0.8 to 1.

[0034] Experiments have shown that, on the one hand, if the ratio of L1 to d is less than 0.8, the heat conduction area between the first plate 240 of the cooling component 120 and the first part 210 of the battery cell 110 will be small, resulting in poor heat dissipation of the first part 210. On the other hand, if the ratio of L1 to d is greater than 1, the first plate 240 of the cooling component 120 will interfere with the terminal post 230 during installation, making the installation of the cooling component 120 inconvenient and potentially affecting the structural stability of the battery cell assembly 100. Therefore, setting the ratio of the dimension L1 of the first plate 240 in the first direction to the distance d between the terminal post 230 and the side plate 250 in the first direction within the range of 0.8 to 1 ensures that the dimension of the first plate 240 in the first direction is sufficient to cover the high-temperature area of ​​the first part 210, thereby ensuring good heat dissipation of the first part 210 of the battery cell 110. It also avoids interference between the first plate 240 and the terminal post 230, ensuring the ease of installation of the cooling component 120.

[0035] Similarly, the dimension L2 of the side plate 250 in the height direction of the cell 110 will also affect the heat dissipation effect of the side 220 of the cell 110. For details, please refer to... Figure 2 , Figure 5 , Figure 5 yes Figure 1In the front view of the battery cell assembly 100, on the one hand, if the dimension L2 of the side plate 250 in the height direction of the battery cell 110 is too short, the heat conduction area between the side plate 250 of the cooling component 120 and the side portion 220 of the battery cell 110 will be small, resulting in poor heat dissipation of the side portion 220. On the other hand, the temperature of the side portion 220 of the battery cell 110 near the first plate 240 is higher, while the temperature of the portion farther from the top plate is relatively lower. In the actual cooling process, the cooling effect of the cold plate is roughly the same for all positions of the side portion 220. If the length of the side plate 250 is too long, the originally higher temperature position of the side portion 220 will be effectively dissipated, keeping the temperature of that position within a predetermined range, while the originally lower temperature position of the side portion 220 will be even lower after heat dissipation, resulting in a certain temperature difference between the two positions. This temperature difference will affect the cycle life and safety of the battery cell assembly 100.

[0036] To address the aforementioned issues, in some embodiments, the ratio of the dimension L2 of the side plate 250 in the height direction of the cell 110 to the height h of the cell 110 is set in the range of 0.55 to 0.65.

[0037] Experiments have shown that, on the one hand, if the ratio of the dimension L2 of the side plate 250 in the height direction of the cell 110 to the height h of the cell 110 is less than 0.55, the heat dissipation area of ​​the side plate 250 will be insufficient, and it will be unable to effectively dissipate heat from the side 220 of the cell 110. On the other hand, if the ratio of the dimension L2 of the side plate 250 in the height direction of the cell 110 to the height h of the cell 110 is greater than 0.65, the temperature distribution of the side 220 of the cell 110 will be uneven. Specifically, the temperature will be higher in the area near the top plate and lower in the area away from the top plate, resulting in a large temperature difference between the two. When the ratio of the dimension L2 of the side plate 250 in the height direction of the cell 110 to the height h of the cell 110 is set in the range of 0.55 to 0.65, it can not only ensure that the cooling effect of the side 220 of the cell 110 is good, but also effectively control the temperature difference between the upper and lower positions of the side 220 of the cell 110, thereby maintaining a uniform temperature distribution of the cell 110, reducing the potential risks caused by uneven temperature of the cell 110, and thus effectively extending the service life of the cell assembly 100.

[0038] In the above embodiments, please refer to Figure 1 , Figure 2The cell 110 includes a cell body 260 and an insulating film 270 covering the outer surface of the cell body 260. The cooling component 120 is bonded to the insulating film 270 by thermally conductive adhesive (not shown in the figure). However, due to the insufficient bonding strength of the insulating film 270, the connection between the cell 110 and the cooling component 120 may loosen due to the vibration of the cell assembly 100 during daily use. Especially in the current mainstream CTP (Cell To Pack) battery structure, the lack of end plate fixation makes the connection between the cell 110 and the cooling component 120 more susceptible to instability due to the movement of the cell assembly 100, resulting in a greater risk of loosening of the connection between the two.

[0039] Therefore, to reduce the risk of loosening of the connection between the battery cell 110 and the cooling component 120, this embodiment proposes an improved structural design. Specifically, the battery cell 110 includes a battery cell body 260 and an insulating film 270 covering the outer surface of the battery cell body 260. The insulating film 270 not only protects the battery cell 110 but also acts as an insulator between the cooling component 120 and the battery cell body 260. The insulating film 270 has a first window 280 and a second window 290, so that the first plate 240 can abut against the first part 210 of at least one battery cell 110 through the first window 280 and be bonded to the battery cell body 260 with thermally conductive adhesive. The side plate 250 can abut against the side part 220 of at least one battery cell 110 through the second window 290 and be bonded to the battery cell body 260 with thermally conductive adhesive.

[0040] In this embodiment, the structural design of the first window portion 280 and the second window portion 290 allows the first plate 240 and the side plate 250 of the cooling component 120 to be firmly bonded to the cell body 260 of at least one cell 110 using thermally conductive adhesive. That is, the thermally conductive adhesive can directly act between the cooling component 120 and the cell body 260, thereby enhancing the bonding strength and reducing the risk of loosening between the cooling component 120 and the cell 110 due to insufficient bonding strength of the insulating film 270.

[0041] Furthermore, to ensure the bonding strength between the first plate 240 of the cold plate and the first part 210 of the battery cell 110, it is necessary to ensure that the first window portion 280 and the first plate 240 have a sufficiently large relative area. (See reference...) Figure 2 , Figure 6 and Figure 7 , Figure 6 yes Figure 2 A top view of multiple 110 battery cells in the middle. Figure 7 yes Figure 6In the enlarged perspective view of section B, in some embodiments, when the distance d between the electrode post 230 and the side plate 250 of the cold plate is fixed in the first direction, the larger the dimension L3 of the first window portion 280 in the first direction, the larger the bonding area of ​​the thermally conductive adhesive between the first plate 240 and the cell body 260, resulting in higher heat conduction efficiency and bonding strength. However, if the dimension L3 of the first window portion 280 in the first direction is greater than the dimension L1 of the first plate 240 in the first direction, the first plate 240 will not be able to completely cover the first window portion 280, causing a portion of the first window portion 280 to be exposed. The exposed portion of the cell 110 surface requires additional insulation measures to prevent short circuits. Therefore, to avoid the above problems, L3 must be less than L1 to ensure that the first plate 240 can cover the first window portion 280.

[0042] Based on the above considerations, in some embodiments, while the ratio of L1 to d should be within the range of 0.8 to 1, the ratio of the dimension L3 of the first window portion 280 in the first direction to d is set between 0.6 and 0.8. This ratio range ensures that the relative area between the first window portion 280 and the first plate 240 is sufficient without causing the window portion size to be too large. That is, it can ensure the bonding strength between the first plate 240 and the first portion 210 while also reducing the risk of short circuit in the battery cell 110.

[0043] What is easy to understand is that it can be used as a reference. Figure 2 , Figure 6 and Figure 7 If the dimension W1 of the first window portion 280 in the second direction is too small, the contact area between the first plate 240 and the cell body 260 may be insufficient, resulting in a relatively small area between them. This leads to poor adhesion strength, making the cooling component 120 of the cell assembly 100 prone to detachment during use, thus affecting the heat dissipation efficiency of the cell assembly 100 and potentially causing safety hazards. Conversely, if the dimension W1 of the first window portion 280 in the second direction is too large, the dimension of the insulating film 270 in the second direction will be relatively small, making the insulating film 270 prone to warping, detachment, or damage, thereby affecting the safety of the cell assembly 100 and increasing the risk of short circuits.

[0044] To address the aforementioned issues, in some embodiments, the ratio between the dimension W1 of the first window portion 280 in the second direction and the dimension W of the battery cell 110 in the second direction is set within the range of 0.5 to 0.8. Experimental verification has shown that when the ratio of W1 to W is controlled within this range, it ensures sufficient bonding area and bonding strength between the first plate 240 and the battery cell 110, while also effectively preventing the insulating film 270 from lifting or falling off, thereby ensuring the safety of the battery cell assembly 100.

[0045] In some embodiments, the ratio between the dimension L3 of the first window portion 280 in the first direction and the dimension L1 of the first plate 240 in the first direction is set in the range of 0.6 to 1. On the one hand, setting the ratio of L3 to L1 to no more than 1 ensures that the first window portion 280 does not exceed the length of the first plate 240 in the first direction, that is, the first plate 240 can completely cover the first window portion 280 in the first direction, so as to avoid the exposure of part of the first window portion 280, which could lead to a short circuit in the cell 110. On the other hand, setting the ratio of L3 to L1 to no less than 0.6 ensures that the relative area between the first plate 240 and the cell body 260 is large, so that the two have a strong adhesive strength.

[0046] In some embodiments, reference may be made to Figure 2 , Figure 8 , Figure 8 yes Figure 2 In a side view of multiple battery cells 110, the ratio between the dimension L4 of the second window portion 290 in the height direction of the battery cell 110 and the height h of the battery cell 110 is set in the range of 0.5 to 0.6.

[0047] Experiments have shown that, on the one hand, if the ratio of L4 to h is less than 0.5, the relatively small area between the side plate 250 and the second window 290 may result in insufficient adhesion between the side plate 250 and the cell body 260 through the second window 290, leading to a higher risk of unstable cooling plate connection during the use of the cell assembly 100. On the other hand, setting the ratio of L4 to h to less than 0.6 ensures that the side plate 250 can completely cover the second window 290 in the second direction, thus preventing partial exposure of the second window 290 and potential short circuits in the cell 110.

[0048] In some embodiments, reference may be made to Figure 2 , Figure 8The ratio of the dimension W2 of the second opening portion 290 in the second direction to the width W of the cell 110 is set within the range of 0.5 to 0.7. On the one hand, when the ratio of W2 to W is greater than 0.5, it ensures that the relative area between the side plate 250 and the second opening portion 290 is large, resulting in a higher bonding strength between the side plate 250 and the cell body 260 through the second opening portion 290. This reduces the risk of unstable connection between the cooling component 120 and the cell assembly 100 during daily use. On the other hand, when the ratio of W2 to W is less than 0.7, it ensures that the dimension of the insulating film 270 in the second direction is small, making it less prone to warping, peeling, or damage. This reduces the risk of short circuit in the cell assembly 100 and ensures the safety of the cell assembly 100.

[0049] This invention provides a battery cell assembly 100, which includes at least one battery cell 110 and a cooling component 120. Each battery cell 110 has a first portion 210 with a terminal post 230 and a side portion 220 connected to one side of the first portion 210. The cooling component 120 is used to cool at least one battery cell 110 and includes a first plate 240 and a side plate 250 connected to one side of the first plate 240. The first plate 240 abuts against the first portion 210 of at least one battery cell 110, and the side plate 250 abuts against the side portion 220 of at least one battery cell 110. The battery cell assembly 100 provided by this invention, by thermally connecting the first plate 240 and the side plate 250 to the first portion 210 and the side portion 220 of the battery cell 110 respectively, enables the cooling plate to cool the high-temperature parts of the battery cell assembly 100 during fast charging, thereby effectively reducing the risk of local overheating of the battery cell assembly 100.

[0050] This utility model also provides a battery pack, which includes the above-mentioned cell assembly 100 and has all the advantages of the above-mentioned cell assembly 100, which will not be repeated here.

[0051] The embodiments of this utility model have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A battery cell assembly, characterized in that, include: At least one battery cell, each of the battery cells having a first part and a side part connected to one side of the first part, each of the battery cells including an electrode post disposed in the first part; and A cooling component for cooling at least one of the battery cells, and comprising a first plate and a side plate connected to one side of the first plate; The first plate abuts against the first portion of at least one of the battery cells, and the side plate abuts against the side portion of at least one of the battery cells.

2. The battery cell assembly according to claim 1, characterized in that, 0.8≤L1 / d≤1; where L1 is the dimension of the first plate in the first direction, d is the distance between the pole post and the side plate in the first direction, and the first direction is the direction in which the first plate points to the pole post.

3. The cell assembly according to claim 2, characterized in that, 0.55≤L2 / h≤0.65; where h is the height of at least one of the battery cells, and L2 is the dimension of the side plate in the height direction of at least one of the battery cells.

4. The battery cell assembly according to any one of claims 1-3, characterized in that, Each of the battery cells includes a battery cell body and an insulating film covering the outer surface of the battery cell body. The insulating film has a first window and a second window. The first plate abuts against at least one of the battery cell bodies through the first window to abut against the first part of at least one of the battery cells, and the side plate abuts against at least one of the battery cell bodies through the second window to abut against the side part of at least one of the battery cells.

5. The cell assembly according to claim 4, characterized in that, 0.8≤L1 / d≤1, 0.6≤L3 / d≤0.8; where L1 is the dimension of the first plate in the first direction, L3 is the dimension of the first window portion in the first direction, d is the distance between the pole post and the side plate in the first direction, and the first direction is the direction in which the first plate points to the pole post.

6. The cell assembly according to claim 5, characterized in that, 0.5≤W1 / W≤0.8; where W is the size of the battery cell in the second direction, W1 is the size of the first window portion in the second direction, and the second direction is the arrangement direction of the plurality of battery cells.

7. The battery cell assembly according to claim 4, characterized in that, 0.6≤L3 / L1≤1; where L1 is the dimension of the first plate in the first direction, and L3 is the dimension of the first window portion in the first direction.

8. The cell assembly according to claim 6, characterized in that, 0.55≤L2 / h≤0.65, 0.5≤L4 / h≤0.6; where L2 is the dimension of the side plate in the height direction of at least one of the battery cells, h is the height of at least one of the battery cells, and L4 is the dimension of the second window portion in the height direction of at least one of the battery cells.

9. The battery cell assembly according to claim 8, characterized in that, 0.5≤W2 / W≤0.7; where W is the width of the battery cell and W2 is the dimension of the second window portion in the second direction.

10. A battery pack, characterized in that, Includes the battery cell pack as described in any one of claims 1-9.

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