Battery cell assembly, battery module and battery pack

Abstract

The utility model belongs to the technical field of power batteries, and particularly relates to a battery cell assembly and a battery pack. The battery cell assembly comprises a battery cell group, and the battery cell group comprises a plurality of stacked battery cells; the heating film extends along the stacking direction of the plurality of battery cells and covers at least part of the battery cell group, the heating film is connected with the battery cells, and the heating film is provided with a redundant part; and the redundant part is suitable for extending along the stacking direction of the plurality of battery cells when the battery cells expand so as to compensate the expansion amount of the battery cells. The battery cell assembly, the battery module and the battery pack at least have the following beneficial effects that the heating film is provided with the redundant part, so that when the battery cell expands, the whole heating film can stretch to compensate the expansion displacement of the battery cell, and the risk that the heating film is pulled when the battery cell expands is reduced; therefore, the risks of degumming and dry burning of the heating film are reduced, and the safety performance of the battery cell assembly, the battery module and the battery pack is further improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of power batteries, and in particular relates to a battery core assembly, a battery module and a battery pack. Background Art

[0002] Charging lithium batteries at excessively low temperatures typically results in lithium deposition, which can lead to safety failure. Therefore, to meet usage requirements, a heating film is installed within the battery module to heat the cells at low temperatures, ensuring that the battery module is charged at the appropriate temperature and preventing lithium deposition, which could lead to safety accidents. However, over time, the battery cells will expand and shift along the length of the battery module, making it easy for the heating film to separate from the cells, causing dry-burning issues and compromising safety performance. Utility Model Content

[0003] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a battery cell assembly, a battery module and a battery pack, which are used to solve the problem in the prior art that the heating film is easily separated from the battery cell when the battery cell expands, avoid dry burning and improve the safety performance of the battery cell assembly, battery module and battery pack.

[0004] To achieve the above-mentioned and other related purposes, the present invention provides a battery cell assembly, comprising:

[0005] A battery cell group, the battery cell group comprising a plurality of stacked battery cells;

[0006] A heating film, wherein the heating film extends along the stacking direction of the plurality of battery cells and covers at least a portion of the battery cell group, the heating film is connected to the battery cells, and the heating film has a redundant portion, and the redundant portion is suitable for stretching along the stacking direction of the plurality of battery cells to compensate for the expansion of the battery cells when the battery cells expand.

[0007] Optionally, the redundant portion protrudes from the remaining portion of the heating film in a direction away from the battery cell.

[0008] Optionally, the redundant portion includes a folding structure.

[0009] Optionally, a portion of the heating film is folded back and forth along the stacking direction of the multiple battery cells to form the folded structure.

[0010] Optionally, the redundant portion includes a protruding structure.

[0011] Optionally, a portion of the heating film bulges in a direction away from the battery cell to form the convex structure.

[0012] Optionally, there are multiple redundant parts, and the multiple redundant parts are distributed along the stacking direction of the multiple battery cells. The extension amount of the redundant parts distributed in the middle of the battery cell group gradually increases to the extension amount of the redundant parts distributed at both ends of the battery cell group.

[0013] Optionally, the redundant portion corresponds to the fitting position of two adjacent battery cells.

[0014] Optionally, the heating film is provided with a backing adhesive bonded to the battery core, and the backing adhesive avoids the redundant portion.

[0015] Optionally, the redundant portion is formed by thermoforming.

[0016] Optionally, there are multiple redundant parts, and all of the multiple redundant parts are folded structures; or, all of the multiple redundant parts are convex structures; or, some of the multiple redundant parts are folded structures, and the other parts are convex structures.

[0017] Optionally, the heating film is provided on one side or two opposite sides of the battery cell group.

[0018] Optionally, the heating films are provided on opposite sides of the battery cell group, and the redundant parts on the two heating films on both sides are both raised structures; or, the redundant parts on the two heating films on both sides are both folded structures; or, the redundant part on one of the two heating films on both sides is a raised structure, and the redundant part on the other is a folded structure.

[0019] To achieve the above objectives and other related objectives, the present application also provides a battery module, including the battery cell assembly described above.

[0020] To achieve the above objectives and other related objectives, the present application also provides a battery pack, including the battery cell assembly as described above.

[0021] As described above, the battery cell assembly, battery module and battery pack of the present invention have at least the following beneficial effects: the heating film has a redundant portion so that when the battery cell expands, the heating film as a whole can stretch to compensate for the expansion displacement of the battery cell, reducing the risk of the heating film being pulled when the battery cell expands, thereby reducing the risk of degumming and dry burning of the heating film, and thereby improving the safety performance of the battery cell assembly, battery module and battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a structural diagram of the first embodiment of the battery cell assembly of the present utility model;

[0023] Figure 2 for Figure 1 A top view of the battery cell assembly in FIG.

[0024] Figure 3 for Figure 2 A magnified schematic diagram of part A in the middle;

[0025] Figure 4 This is a top view of the second embodiment of the battery cell assembly of the present utility model;

[0026] Figure 5 for Figure 4 A magnified schematic diagram of part B in the middle;

[0027] Figure 6 This is a top view of the third embodiment of the battery cell assembly of the present utility model;

[0028] Figure 7 This is a top view of the fourth embodiment of the battery cell assembly of the present invention.

[0029] Part Number Description

[0030] Battery cell group 1, battery cell 11, heating film 2, folding structure 21, protruding structure 22. DETAILED DESCRIPTION

[0031] The following describes the implementation of the present invention through specific embodiments. People familiar with this technology can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0032] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for understanding and reading by those familiar with this technology, and are not used to limit the conditions for implementation of the present invention. Therefore, they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed in the present invention without affecting the efficacy and purpose of the present invention. At the same time, terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments in their relative relationships should also be considered as the scope of implementation of the present invention without substantially changing the technical content.

[0033] See also Figures 1 to 7In some optional embodiments, the present application provides a battery cell assembly, comprising a battery cell group 1 and a heating film 2. The battery cell group 1 comprises a plurality of stacked battery cells 11. The heating film 2 extends along the stacking direction of the plurality of battery cells 11 and covers at least a portion of the battery cell group 1. The heating film 2 is connected to the battery cells 11 and has a redundant portion. The redundant portion is adapted to stretch along the stacking direction of the plurality of battery cells 11 to compensate for the expansion displacement of the battery cells 11 when the battery cells 11 expand. In the present application, the stacking direction of the plurality of battery cells 11, the thickness direction of the battery cells 11, the length direction of the battery cell group 1, and the extension direction of the heating film 2 are the same, i.e., the Y direction in the accompanying drawings.

[0034] Optionally, the redundant portion protrudes from the rest of the heating film 2 in a direction facing away from the battery cell 11, or in other words, the redundant portion protrudes from the rest of the heating film 2 in the thickness direction of the heating film 2 and the redundant portion faces away from the battery cell 11. The redundant portion protrudes in a direction facing away from the battery cell 11, so that the redundant portion is located on the side of the heating film 2 facing away from the battery cell 11 and does not occupy the space between the heating film 2 and the battery cell 11, which is beneficial to improving the flatness of the fit between the heating film 2 and the battery cell 11. In the present application, the protruding direction of the redundant portion, the thickness direction of the heating film 2, the length direction of the battery cell 11, and the width direction of the battery cell group 1 are the same, that is, the X direction in the accompanying drawings; the height direction of the battery cell 11 is the same as the height direction of the battery cell group 1, that is, the Z direction in the accompanying drawings.

[0035] Optionally, heating films 2 are provided on one side or both opposite sides of the cell group 1. The number of redundant parts can be one or more; when there are multiple redundant parts, the multiple redundant parts located on the same side of the cell group 1 are distributed along the stacking direction of the multiple cells 11.

[0036] Optionally, the heating film 2 is bonded to the battery cell 11; wherein, the heating film 2 is provided with a backing glue bonded to the battery cell 11, the backing glue avoids the redundant part, and the backing glue is located on the side of the heating film 2 facing the battery cell 11. The backing glue avoids the redundant part so that the redundant part is not bonded to the battery cell 11, which is conducive to the flexible stretching of the redundant part when the battery cell 11 expands.

[0037] Optionally, the redundant portion corresponds to the fitting position of two adjacent battery cells 11, that is, each redundant portion can act on two adjacent battery cells 11 at the same time to compensate for the expansion displacement of the two adjacent battery cells 11, with a compact layout and good expansion absorption effect.

[0038] Optionally, the redundant part is hot-pressed, or in other words, the redundant part is hot-pressed and formed on the heating film 2. The redundant part formed by hot pressing has a stable structure and is not prone to spontaneous deformation, so that the redundant part can maintain a stable shape in a natural state, avoiding the generation of internal stress and affecting the bonding effect between the heating film 2 and the battery cell 11.

[0039] In the battery cell assembly of the above embodiment, the heating film 2 has a redundant portion that can be stretched, so that the heating film 2 can provide a stretching margin to adapt to the expansion changes of the battery cell 11 when the battery cell 11 expands. The heating film 2 is not easily pulled, which is beneficial to reducing the risk of separation between the heating film 2 and the battery cell 11, thereby reducing the risk of dry burning, and further beneficial to improving the safety performance of the battery cell assembly.

[0040] See also Figures 1 to 3 In some optional embodiments, the redundant portion includes a folded structure 21 .

[0041] Optionally, there are multiple redundant parts, and all of the redundant parts are folding structures 21.

[0042] Optionally, a portion of the heating film 2 is folded back and forth along the stacking direction of the multiple battery cells 11 to form a folded structure 21 .

[0043] In the battery cell assembly of the above embodiment, the redundant part is a folding structure 21 that occupies a small space. Especially when the required extension margin is relatively large, the redundant part requires a relatively large space in the width direction of the battery cell group 1. The use of the folding structure 21 can not only meet the extension requirements, but also help to reduce the space occupied in the length direction of the battery cell group 1.

[0044] See also Figure 6 In some optional embodiments, the redundant portion includes a raised structure 22 .

[0045] Optionally, there are multiple redundant parts, and all of the redundant parts are protruding structures 22 .

[0046] Optionally, a portion of the heating film 2 is raised in a direction facing away from the battery cell 11 to form a protruding structure 22. Furthermore, the protruding structure 22 includes an arc-shaped protrusion or a protrusion of other shapes.

[0047] In the battery cell assembly of the above embodiment, the redundant part is a raised structure 22, which has a simple structure and is easy to be hot-pressed. Moreover, the raised structure 22 is not folded back and forth, and is more likely to stretch out when the battery cell 11 expands, and has higher flexibility in stretching out.

[0048] See also Figure 4 、 Figure 5 and Figure 7 In some optional embodiments, there are multiple redundant parts, some of which are folding structures 21, and the other parts are protruding structures 22. They are easy to set up and flexible to stretch, which is conducive to adapting to different needs.

[0049] Optional, see Figure 7 Among the multiple redundant parts located on the same side, part of them is a folding structure 21, and the other part is a protruding structure 22.

[0050] See also Figure 4 、 Figure 5 and Figure 7 In some optional embodiments, there are multiple redundant parts, and the stretching amount of the redundant parts distributed in the middle of the battery cell group 1 is greater than the stretching amount of the redundant parts distributed at both ends of the battery cell group 1.

[0051] Optionally, the stretching amount of the redundant parts distributed in the middle of the battery cell group 1 gradually increases toward the stretching amounts of the redundant parts distributed at both ends of the battery cell group 1 .

[0052] It is understandable that the extension amount of the redundant parts can be set according to demand, and the total extension amount of the multiple redundant parts should not be less than the expansion displacement of the battery cell group 1 during its service life.

[0053] In the battery cell assembly of the above embodiment, in the length direction of the battery cell group 1, the expansion displacement of the battery cell 11 located in the middle of the battery cell group 1 gradually increases to the battery cell 11 located at both ends of the battery cell group 1, and the stretching amount of the redundant parts distributed at different positions matches the expansion displacement of the corresponding battery cell 11, which can not only meet the expansion changes of the battery cell 11, but also reduce the waste of the heating film 2, which is conducive to reducing costs.

[0054] See also Figure 2 、 Figure 4 and Figure 6 In some optional embodiments, heating films 2 are provided on both opposite sides of the battery cell group 1 .

[0055] Optional, see Figure 6 The redundant parts on the two heating films 2 on both sides are both raised structures 22.

[0056] Optional, see Figure 2 The redundant parts on the two heating films 2 on both sides are folded structures 21.

[0057] Optional, see Figure 4 The redundant portion on one of the two heating films 2 on both sides is a protruding structure 22 , and the redundant portion on the other one is a folding structure 21 .

[0058] In the battery cell assembly of the above embodiment, heating films 2 are provided on both sides of the battery cell group 1, which is beneficial to improving the heating efficiency. Moreover, the redundant parts on the heating films 2 on both sides can be flexibly set as a folding structure 21 or a protruding structure 22 according to needs, so as to flexibly buffer the expansion displacement of the battery cell 11, and the scope of application is more flexible and wide.

[0059] See also Figures 1 to 7 In some optional embodiments, the present application provides a battery module, which includes the battery cell assembly in any of the above embodiments.

[0060] See also Figures 1 to 7In some optional embodiments, the present application provides a battery pack, which includes the battery cell assembly in any of the above embodiments.

[0061] The battery cell assembly, battery module and battery pack of the present invention can buffer the expansion displacement of the battery cell 11 when expansion occurs through the heating film 2 with redundant parts, reduce the risk of separation of the heating film 2 from the battery cell 11 and the risk of dry burning of the heating film 2, which is beneficial to improving the stability of the structure, thereby helping to improve the safety performance of the battery cell assembly, battery module and battery pack.

[0062] Throughout this specification, references to terms such as "this embodiment," "example," and "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0063] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed in the present invention are intended to be covered by the claims of the present invention.

Claims

1. A battery cell assembly, characterized in that: include: A battery cell group, the battery cell group comprising a plurality of stacked battery cells; A heating film, wherein the heating film extends along the stacking direction of the plurality of battery cells and covers at least a portion of the battery cell group, the heating film is connected to the battery cells, and the heating film has a redundant portion, and the redundant portion is suitable for stretching along the stacking direction of the plurality of battery cells to compensate for the expansion of the battery cells when the battery cells expand.

2. The battery core assembly according to claim 1, characterized in that The redundant portion protrudes from the remaining portion of the heating film in a direction facing away from the battery cell.

3. The battery core assembly according to claim 1 or 2, characterized in that: The redundant portion includes a folded structure.

4. The battery core assembly according to claim 3, characterized in that: A portion of the heating film is reciprocally folded along the stacking direction of the plurality of battery cells to form the folded structure.

5. The battery core assembly according to claim 1 or 2, characterized in that: The redundant portion includes a protruding structure.

6. The battery core assembly according to claim 5, characterized in that: A portion of the heating film bulges in a direction away from the battery cell to form the convex structure.

7. The battery cell assembly according to claim 1, characterized in that There are multiple redundant parts, which are distributed along the stacking direction of the battery cells. The extension amount of the redundant parts distributed in the middle of the battery cell group gradually increases to the extension amount of the redundant parts distributed at both ends of the battery cell group.

8. The battery core assembly according to claim 1, characterized in that: The redundant portion corresponds to the bonding position of two adjacent battery cells.

9. The battery core assembly according to claim 1, characterized in that: The heating film is provided with a backing adhesive for bonding with the battery core, and the backing adhesive avoids the redundant portion.

10. The battery core assembly according to claim 1, characterized in that: The redundant portion is formed by hot pressing.

11. The battery core assembly according to claim 1, characterized in that: There are multiple redundant parts, and all of the multiple redundant parts are folding structures; or, all of the multiple redundant parts are convex structures; or, some of the multiple redundant parts are folding structures, and the other parts are convex structures.

12. The battery cell assembly according to claim 1, characterized in that The heating film is provided on one side or two opposite sides of the battery cell group.

13. The battery cell assembly according to claim 1, characterized in that: The heating films are provided on opposite sides of the battery cell group, and the redundant parts on the two heating films on both sides are both convex structures; or, the redundant parts on the two heating films on both sides are both folded structures; or, the redundant part on one of the two heating films on both sides is a convex structure, and the redundant part on the other is a folded structure.

14. A battery module, characterized in that: Comprising the battery core assembly according to any one of claims 1 to 13.

15. A battery pack, characterized in that: Comprising the battery core assembly according to any one of claims 1 to 13.

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