Battery cell assembly, battery module and battery pack
By introducing a buffer connection into the heating film to compensate for the expansion displacement of the battery cell, the disengagement and dry burning problems caused by low-temperature charging of lithium batteries and expansion of the battery cell are solved, which improves safety performance and reduces costs.
Patent Information
- Application Number
- CN202422307136.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-20
- Publication Date
- 2025-07-25
- Estimated Expiration
- 2034-09-20
AI Technical Summary
In the prior art, lithium batteries are prone to lithium removal during low-temperature charging, and the heating film is prone to disengage from the battery cell when expanding, resulting in a risk of dry burning and affecting safety performance.
A heating film is designed, including a buffer connection and a heating part. The buffer connection is stretched in the stacking direction of the battery cell when the battery cell expands to compensate for the expansion displacement. The width of the buffer connection is smaller than that of the heating part to ensure a stable connection between the heating film and the battery cell.
The risk of heating film separation and dry burning from the battery cell is reduced, the safety performance of battery cell components, battery modules and battery packs is improved, and the consumption of heating film materials is reduced, and the cost is reduced.
Smart Images
Figure CN223156168U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of power batteries, and particularly relates to a battery cell assembly, a battery module and a battery pack. Background Art
[0002] When a lithium battery is charged at too low a temperature, lithium plating generally occurs, which will cause the safety failure of the lithium battery. Therefore, in order to meet the use requirements, a heating film is arranged in the battery module to heat the battery cells in a low-temperature state, so that the battery module can be charged at a suitable charging temperature, preventing lithium plating of the lithium battery and avoiding safety accidents. However, during long-term use, the battery cells will undergo cyclic expansion and displacement in the length direction of the battery module, causing the heating film adhered to the battery cells to easily detach from the battery cells, thus causing a dry burning problem. Summary of the Utility Model
[0003] In view of the above-mentioned disadvantages of the prior art, the purpose of the present utility model is to provide a battery cell assembly, a battery module and a battery pack, which are used to solve the problem that the heating film is easily detached from the battery cells when the battery cells expand in the prior art, and avoid dry burning to improve the safety performance of the battery cell assembly, the battery module and the battery pack.
[0004] To achieve the above purpose and other related purposes, the present utility model provides a battery cell assembly, including:
[0005] A battery cell group, the battery cell group includes a plurality of stacked battery cells;
[0006] A heating film, the heating film includes a buffer connection part and a plurality of heating parts, the plurality of heating parts are arranged along the stacking direction of the plurality of battery cells and are connected to the corresponding battery cells, the buffer connection part is located between two adjacent heating parts and is connected to the two adjacent heating parts, the width of the buffer connection part in the height direction of the battery cell is smaller than the width of the heating part in the height direction of the battery cell, and the buffer connection part is adapted to be stretched along the stacking direction of the plurality of battery cells when the battery cell expands to compensate for the expansion displacement of the battery cell.
[0007] Optionally, the buffer connection part includes a bending structure.
[0008] Optionally, the heating part and the buffer connection part are in the same plane in the thickness direction of the heating film.
[0009] Optionally, the bending structure includes an arc segment.
[0010] Optionally, the heating part is square.
[0011] Optionally, the battery cell group has a center line that bisects the battery cell group in the height direction of the battery cell group, and two adjacent bending structures in the stacking direction of the plurality of battery cells are distributed on both sides of the center line.
[0012] Optionally, the bending structure includes a V-shaped section.
[0013] Optionally, the heating part is V-shaped, the width of the heating part gradually increases from near the bending structure to far from the bending structure, and the minimum width of the heating part is D3, the maximum width of the bending structure is D4, and D4 < D3.
[0014] Optionally, the battery cell group has a center line that bisects the battery cell group in the height direction of the battery cell group, and two adjacent bending structures in the stacking direction of the plurality of battery cells are distributed on the same side of the center line.
[0015] Optionally, a plurality of the heating parts are connected by the bending structure to form a wavy structure.
[0016] Optionally, the heating part is provided with an adhesive for bonding to the battery cell, and the adhesive avoids the buffer connection part.
[0017] Optionally, the buffer connection part corresponds to the fitting position of two adjacent battery cells.
[0018] To achieve the above and other related purposes, the present application also provides a battery module, including the battery cell assembly as described above.
[0019] To achieve the above and other related purposes, the present application also provides a battery pack, including the battery cell assembly as described above.
[0020] As described above, the battery cell assembly, battery module, and battery pack of the present utility model have at least the following beneficial effects: adjacent heating parts are connected by a buffer connection part, and the buffer connection part can change its shape and be stretched when the battery cell expands to buffer the expansion displacement of the battery cell, which is beneficial to reducing the risk of the heating film detaching from the battery cell and the risk of dry burning, so as to improve the safety performance; and the width of the buffer connection part is smaller than the width of the heating part, which is beneficial to flexible stretching on the one hand and saving the material of the heating film on the other hand, so as to reduce the cost. Description of the Drawings
[0021] Figure 1 It is a side view of the first embodiment of the battery cell assembly of the present utility model;
[0022] Figure 2 It is a side view of the second embodiment of the battery cell assembly of the present utility model.
[0023] Description of the Part Numbers
[0024] Cell stack 1, cell 11, center line 12, heating film 2, heating part 21, buffer connection part 22. Detailed implementation mode
[0025] The following specific embodiments illustrate the implementation modes of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.
[0026] It should be noted that the structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in the art to understand and read, and are not used to limit the limiting conditions under which the present invention can be implemented. Therefore, they do not have technical essential significance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope that can be covered by the technical content disclosed in the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" cited in this specification are only for the convenience of clear narration, and are not used to limit the scope under which the present invention can be implemented. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope under which the present invention can be implemented.
[0027] Refer to Figure 1 and Figure 2 , in some alternative embodiments, the present application provides a cell assembly, which includes a cell stack 1 and a heating film 2. The cell stack 1 includes a plurality of cells 11 arranged in a stacked manner. The heating film 2 includes a buffer connection part 22 and a plurality of heating parts 21. The plurality of heating parts 21 are arranged along the stacking direction of the plurality of cells 11 and are connected to the corresponding cells 11. The buffer connection part 22 is located between two adjacent heating parts 21 and is connected to the two adjacent heating parts 21, so that two adjacent heating parts 21 are connected through the buffer connection part 22. The width of the buffer connection part 22 in the height direction of the cell 11 is smaller than the width of the heating part 21 in the height direction of the cell 11, and the buffer connection part 22 is adapted to be stretched along the stacking direction of the plurality of cells 11 when the cell 11 expands to compensate for the expansion displacement of the cell 11. In the present application, the stacking direction of the plurality of cells 11, the thickness direction of the cell 11, the length direction of the cell stack 1 and the arrangement direction of the plurality of heating parts 21 are the same, that is, the Y direction in the drawings; the height direction of the cell 11 and the height direction of the cell stack 1 are the same, that is, the Z direction in the drawings.
[0028] Optionally, the heating part 21 is bonded to the cell 11; wherein, the heating part 21 is provided with an adhesive on the back that is bonded to the cell 11, and the adhesive avoids the buffer connection part 22. The adhesive avoiding the buffer connection part 22 enables the buffer connection part 22 not to be bonded to the cell 11, which is beneficial for the buffer connection part 22 to stretch flexibly when the cell 11 expands.
[0029] Optionally, the buffer connection part 22 corresponds to the fitting positions of two adjacent battery cells 11. That is to say, each buffer connection part 22 can act on two adjacent battery cells 11 simultaneously to compensate for the expansion displacement of the two adjacent battery cells 11, with a compact layout and good expansion absorption effect. Specifically, each buffer connection part 22 at least covers the local parts of two battery cells 11 simultaneously.
[0030] For the battery cell assembly of the above embodiment, the heating film 2 has a buffer connection part 22 that can stretch and deform, so that when the battery cell 11 expands, the buffer connection part 22 can be stretched along the expansion direction of the battery cell 11 to buffer and compensate for the expansion displacement of the battery cell 11, which is beneficial to reducing the risk of mutual pulling between adjacent heating parts 21, thereby being beneficial to reducing the risk of the heating film 2 detaching from the battery cell 11 and the risk of dry burning, and further being beneficial to improving the safety performance of the battery cell assembly.
[0031] See Figure 1 and Figure 2 , in some alternative embodiments, the buffer connection part 22 includes a bending structure.
[0032] Optionally, the buffer connection part 22 is formed by hot pressing. The buffer connection part 22 formed by hot pressing has a stable structure and is not prone to spontaneous deformation, enabling the buffer connection part 22 to maintain the stability of its shape in the natural state and avoiding the generation of internal stress that affects the bonding effect between the heating film 2 and the battery cell 11.
[0033] Optionally, the heating part 21 and the buffer connection part 22 are located in the same plane in the thickness direction of the heating film 2. That is to say, the heating part 21 and the buffer connection part 22 are in the same plane, and the surfaces of the heating part 21 and the buffer connection part 22 in the thickness direction of the heating film 2 are flush, which is beneficial to reducing the space requirements, especially in the width direction of the battery cell group 1. The buffer connection part 22 does not protrude from the heating part 21 in the width direction of the battery cell group 1, which is beneficial to reducing the space occupied by the overall battery cell assembly in the width direction. In this application, the thickness direction of the heating film 2, the width direction of the battery cell 11, the width direction of the battery cell group 1, and the width direction of the battery cell assembly are the same.
[0034] For the battery cell assembly of the above embodiment, the buffer connection part 22 adopts a bending structure, which is beneficial to the heating film 2 stretching more flexibly when the battery cell 11 expands, so as to timely adapt to and compensate for the expansion displacement of the battery cell 11.
[0035] See Figure 1 , in some alternative embodiments, the bending structure includes an arc segment. Among them, the arc segment can be a semi - circle.
[0036] Optionally, the heating part 21 is square. In the height direction of the battery cell 11, the width of the heating part 21 is D1, and the width of the buffer connection part 22 is D2, where D2 < D1. The width D2 of the buffer connection part 22 being smaller than the width D1 of the heating part 21 is conducive to the flexible deformation of the heating film 2 to adapt to the expansion of the battery cell 11, and is also conducive to reducing the material consumption of the heating film 2. Additionally, the area of the heating part 21 is larger than that of the buffer connection part 22, increasing the heating area and improving the heating capacity of the heating film 2.
[0037] Optionally, the battery cell group 1 has a center line 12 that bisects the battery cell group 1 in the height direction of the battery cell group 1. Two adjacent bending structures in the stacking direction of the plurality of battery cells 11 are distributed on both sides of the center line 12. This structural design enables the heating film 2 to have sufficient stretching and deformation margins on both sides in the height direction of the battery cell group 1, which is conducive to quickly and evenly compensating for the expansion displacement of the battery cell 11 when the battery cell 11 expands.
[0038] For the battery cell assembly of the above embodiment, the structure of the heating film 2 is simple, the forming and manufacturing are simple, and the cost is low.
[0039] See Figure 2 , in some alternative embodiments, the bending structure includes a V-shaped section.
[0040] Optionally, the bending part of the V-shaped section has a smooth transition.
[0041] Optionally, the heating part 21 is V-shaped, and the width of the heating part 21 gradually increases from near the bending structure to far from the bending structure. The minimum width of the heating part 21 is D3, and the maximum width of the bending structure is D4, where D4 < D3. This is conducive to improving the heating capacity of the heating film 2 and reducing the material consumption of the heating film 2.
[0042] Optionally, the number of bending structures is multiple. In the stacking direction of the plurality of battery cells 11, a plurality of heating parts 21 and a plurality of bending structures are alternately distributed and connected to form a wavy structure extending along the stacking direction of the plurality of battery cells 11. Or, a plurality of heating parts 21 are connected by bending structures to form a wavy structure. The heating film 2 designed in this way is not only conducive to reducing the material consumption of the heating film 2, but also has good stretchability, which is conducive to increasing the stretching amount of the heating film 2 when the battery cell 11 expands, so as to fully compensate for the expansion displacement of the battery cell 11 and reduce the risk of the heating film 2 detaching from the battery cell 11 and dry burning.
[0043] Optionally, the battery cell group 1 has a center line 12 that bisects the battery cell group 1 in the height direction of the battery cell group 1. Two adjacent buffer connection parts 22 in the stacking direction of the plurality of battery cells 11 are distributed on the same side of the center line 12. Among them, the openings of the V-shaped sections and the V-shaped heating parts 21 face in opposite directions.
[0044] See Figure 1and Figure 2 , in some alternative embodiments, the present application provides a battery module, which includes a battery cell assembly as described in any of the foregoing embodiments.
[0045] See Figure 1 and Figure 2 , in some alternative embodiments, the present application provides a battery pack, which includes a battery cell assembly as described in any of the foregoing embodiments.
[0046] For the battery cell assembly, battery module and battery pack of the present utility model, the heating film 2 having the buffer connection portion 22 can compensate for the expansion displacement of the battery cell 11 when the battery cell expands, reduce the risk of the heating film 2 detaching from the battery cell 11 and the risk of dry burning of the heating film 2, which is beneficial to improving the structural stability, and thus beneficial to improving the safety performance of the battery cell assembly, battery module and battery pack; in addition, the width of the buffer connection portion 22 is smaller than the width of the heating portion 21, which is beneficial to reducing the material consumption of the heating film 2 while ensuring the heating performance of the heating film 2, and thus beneficial to reducing the cost.
[0047] In the description of this specification, the descriptions referring to terms such as "this embodiment", "example", "specific example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.
[0048] The above embodiments are only illustrative of the principles and effects of the present utility model, and are not used to limit the present utility model. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present utility model. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present utility model should still be covered by the claims of the present utility model.
Claims
1. A battery cell assembly, characterized in that, Comprising: a battery cell group, the battery cell group including a plurality of stacked battery cells; a heating film, the heating film including a buffer connection portion and a plurality of heating portions, the plurality of heating portions being arranged along the stacking direction of the plurality of battery cells and connected to the corresponding battery cells, the buffer connection portion being located between two adjacent heating portions and connected to the two adjacent heating portions, the width of the buffer connection portion in the height direction of the battery cell being smaller than the width of the heating portion in the height direction of the battery cell, and the buffer connection portion being adapted to be stretched along the stacking direction of the plurality of battery cells when the battery cell expands to compensate for the expansion displacement of the battery cell.
2. The cell assembly according to claim 1, wherein, The buffer connection portion includes a bending structure.
3. The cell assembly according to claim 2, wherein The heating portion and the buffer connection portion are in the same plane in the thickness direction of the heating film.
4. The cell assembly according to claim 2, characterized in that The bending structure includes an arc segment.
5. The cell assembly according to claim 4, wherein The heating portion is square.
6. The cell assembly according to claim 2 or 5, wherein The battery cell group has a center line that bisects the battery cell group in the height direction of the battery cell group, and two adjacent bending structures in the stacking direction of the plurality of battery cells are distributed on both sides of the center line.
7. The cell assembly according to claim 2, wherein The bending structure includes a V-shaped segment.
8. The cell assembly according to claim 7, wherein The heating portion is V-shaped, the width of the heating portion gradually increases from near the bending structure to far from the bending structure, and the minimum width of the heating portion is D3, the maximum width of the bending structure is D4, and D4 < D3.
9. The battery cell assembly according to claim 2 or 8, characterized in that, The battery cell group has a center line that bisects the battery cell group in the height direction of the battery cell group, and two adjacent bending structures in the stacking direction of the plurality of battery cells are distributed on the same side of the center line.
10. The cell assembly according to claim 8, wherein, The plurality of heating portions are connected by the bending structure to form a wavy structure.
11. The cell assembly according to claim 1, characterized in that, The heating portion is provided with an adhesive for bonding to the battery cell, and the adhesive avoids the buffer connection portion.
12. The cell assembly according to claim 1, wherein The buffer connection portion corresponds to the fitting positions of two adjacent battery cells.
13. A battery module, characterized in that, Comprising the battery cell assembly according to any one of claims 1 to 12.
14. A battery pack, characterized in that, Comprising the battery cell assembly according to any one of claims 1 to 12.