Battery cell protection film and battery pack

Abstract

The utility model relates to the technical field of energy storage devices, in particular to a battery cell protective film and a battery pack, the battery cell protective film is used for wrapping the outer surface of a battery cell and comprises a first protective film and a second protective film, the first protective film wraps the upper half part of the battery cell, and the second protective film wraps the lower half part of the battery cell. A first protective film and a second protective film can wrap the whole outer surface of a battery cell, a first lap joint part is arranged on the first protective film, a second lap joint part is arranged on the second protective film, and after the battery cell is wrapped by the first protective film and the second protective film, at least part of the first protective film and at least part of the second protective film are overlapped to form a lap joint area. When the battery cell is taken out, the first protective film and the second protective film can be disconnected in the lap joint area, so that the first protective film and the second protective film wrapping the battery cell are separated, the battery cell can be completely taken out without being damaged, and the cost of the battery cell is saved.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage devices, in particular to a battery core protection film and a battery pack. Background Art

[0002] Most current energy storage batteries use the CTP (cell to pack) method to integrate the cells in series in the battery pack to form the smallest integrated unit. Specifically, the cells are assembled into modules, and then the modules are installed in the battery pack, forming a three-level assembly mode of "cell-module-battery pack". Compared with traditional battery packs, the volume utilization rate of CTP battery packs has increased by 15%-20%, the number of battery pack components has been reduced by 40%, and the production efficiency has increased by 50%.

[0003] In the prior art, the outer surface of the battery cell is usually covered with a complete insulating protective film, and then multiple battery cells are connected in series to form a battery module. When the grouped battery modules are installed in the battery pack, a layer of thermally conductive structural adhesive is usually coated between the bottom of the battery cell and the cold plate structure, which can increase the heat conduction area and thermal conductivity between the battery cell and the cold plate structure. However, since the thermally conductive structural adhesive has strong adhesion after solidification, the battery cell and the cold plate structure are firmly bonded, which makes it difficult to remove the battery cell when repairing a subsequent battery cell failure or recycling the battery cell in the future, which can easily cause deformation and damage to the battery cell, increasing costs.

[0004] Therefore, there is an urgent need for a battery cell protection film and a battery pack to solve the above problems. Utility Model Content

[0005] One purpose of the utility model is to provide a battery core protection film, which can ensure that the battery core is completely removed, avoid battery damage and deformation, and save battery repair and recycling costs.

[0006] To achieve this purpose, the utility model adopts the following technical solutions:

[0007] A battery cell protection film is provided for covering the peripheral outer wall of the battery cell, comprising: a first protective film, the first protective film covering the upper half of the battery cell, and a first overlapping portion being provided on the first protective film; a second protective film, the second protective film covering the lower half of the battery cell, and a second overlapping portion being provided on the second protective film, after the first protective film and the second protective film cover the battery cell, at least a portion of the first overlapping portion and at least a portion of the second overlapping portion are overlapped with each other to form an overlapping area; the fixing force between the first overlapping portion and the second overlapping portion is less than the bonding force between the first protective film and the thermal conductive structural adhesive.

[0008] As an optional scheme for the battery cell protective film, the upper half of the battery cell has an upper surface, and the lower half of the battery cell has a lower surface, the upper surface and the lower surface form the outer wall of the battery cell, the first protective film covers the upper surface, the second protective film covers the lower surface, and the first overlapping portion is attached to the outer wall of the second overlapping portion to form the overlapping area.

[0009] As an optional solution for the battery cell protective film, the second protective film and the lower surface can be detachably bonded together, the second protective film and the lower surface have a first bonding force, the second protective film and the thermal conductive structural adhesive have a second bonding force, and the first bonding force is smaller than the second bonding force.

[0010] As an optional solution for the battery cell protection film, the overlapping area is an adhesive bonding area, and the overlapping length of the overlapping area is 10mm-20mm.

[0011] As an optional solution for the battery cell protection film, the cross-section of the first protection film is U-shaped; and / or the cross-section of the second protection film is U-shaped.

[0012] As an optional solution for the battery cell protection film, a avoidance hole is opened on the first protection film, and the avoidance hole can avoid the protruding structure on the upper part of the battery cell.

[0013] As an optional solution for the battery cell protection film, a plurality of the avoidance holes are opened on the first protection film to correspond to the plurality of the protruding structures on the upper part of the battery cell.

[0014] As an optional solution for the battery cell protective film, the overlapping area is located in the middle of the battery cell.

[0015] The second object of the utility model is to provide a battery pack that can ensure that the battery cells are completely removed, avoid battery damage and deformation, and save battery repair and recycling costs.

[0016] To achieve this purpose, the utility model adopts the following technical solutions:

[0017] A battery pack is provided, comprising a battery cell, a cold plate structure and the battery cell protection film, wherein the battery cell protection film covers the entire outer wall surface of the battery cell, and the second protection film covering the bottom of the battery cell is connected to the cold plate structure.

[0018] As an optional solution for the battery pack, the second protective film is bonded to the cold plate structure by a thermally conductive structural adhesive, and the adhesive force of the thermally conductive structural adhesive is greater than the adhesive force of the overlapping area.

[0019] Beneficial effects of the utility model:

[0020] The utility model provides a battery cell protective film, which is used to cover the outer surface of the battery cell. The battery cell protective film includes a first protective film and a second protective film. The first protective film covers the upper half of the battery cell, and the second protective film covers the lower half of the battery cell. The first protective film and the second protective film can cover the entire outer wall surface of the battery cell. The first protective film is provided with a first overlapping portion, and the second protective film is provided with a second overlapping portion. After the first protective film and the second protective film cover the battery cell, at least part of the first protective film and at least part of the second protective film overlap with each other to form an overlapping area. When the battery cell is taken out, the first protective film and the second protective film can be disconnected in the overlapping area, so that the first protective film and the second protective film covering the battery cell are separated, thereby ensuring that the battery cell is completely taken out without damage, saving the cost of repairing and recycling the battery cell.

[0021] The utility model also provides a battery pack, including a battery cell, a cold plate structure and the above-mentioned battery cell protective film, wherein the battery cell protective film is coated on the outer wall of the battery cell, and the second protective film coated on the bottom of the battery cell is connected to the cold plate structure. When the battery cell is taken out, the first protective film and the second protective film of the battery cell protective film can be disconnected in the overlapping area, so that the first protective film and the second protective film are separated, thereby ensuring that the battery cell can be completely taken out without damage, saving the cost of battery cell repair and recycling. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic front view of a battery cell of a battery cell protection film provided by an embodiment of the utility model in a first direction;

[0023] Figure 2 yes Figure 1 A local enlarged view at point A;

[0024] Figure 3 It is a front view schematic diagram of a battery cell of a battery cell protection film provided by an embodiment of the utility model in a second direction.

[0025] In the figure:

[0026] 100, battery cell; 110, upper half; 120, lower half; 130, peripheral outer wall; 131, upper surface; 132, lower surface; 140, protruding structure;

[0027] 1. first protective film; 11. first overlapping portion; 101. avoidance hole;

[0028] 2. a second protective film; 21. a second overlapping portion;

[0029] 3. Overlap area. DETAILED DESCRIPTION

[0030] The technical solution of the utility model is further described below in conjunction with the accompanying drawings and implementation methods. It is understood that the specific embodiments described herein are only used to explain the utility model, rather than to limit the utility model. It should also be noted that, for the convenience of description, only the parts related to the utility model are shown in the accompanying drawings, rather than all.

[0031] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0033] In this specific embodiment, when looking at the battery cell 100 along the first direction, the structure of the battery cell 100 is as follows: Figure 1 As shown, when looking at the battery cell 100 along the second direction, the structure of the battery cell 100 is as follows Figure 3 As shown; the first direction described in this specific embodiment is the direction facing the small surface of the battery cell 100, that is, Figure 3 The second direction is the direction facing the large surface of the battery cell 100, that is, Figure 1 In the Y direction, the X direction and the Y direction are perpendicular to each other.

[0034] Embodiment 1

[0035] like Figures 1 to 3As shown, the battery cell protection film of the first embodiment is used to cover the peripheral outer wall 130 of the battery cell 100, and the battery cell protection film includes a first protective film 1 and a second protective film 2. The first protective film 1 and the second protective film 2 can cover the entire outer surface of the battery cell 100, wherein the first protective film 1 covers the upper half 110 of the battery cell 100, and the first protective film 1 is provided with a first overlapping portion 11, and the second protective film 2 covers the lower half 120 of the battery cell 100, and the second protective film 2 is provided with a second overlapping portion 21. After the first protective film 1 and the second protective film 2 cover the battery cell 100, at least a portion of the first overlapping portion 11 and at least a portion of the second overlapping portion 21 overlap with each other to form an overlapping area 3.

[0036] The battery cell protection film of the first embodiment is coated on the peripheral outer wall 130 of the battery cell 100. When the battery cell 100 is taken out, the first protective film 1 and the second protective film 2 can be disconnected in advance in the overlapping area 3, so that the first protective film 1 and the second protective film 2 covering the battery cell 100 are separated. Therefore, it can be ensured that the battery cell 100 is completely taken out without causing damage to the battery cell 100, thereby saving the cost of the battery cell 100.

[0037] Embodiment 2

[0038] The cell protection film cell in the second embodiment is different from the first embodiment in that the upper part 110 of the cell 100 has an upper surface 131, the lower part 120 of the cell 100 has a lower surface 132, the upper surface 131 and the lower surface 132 form the peripheral outer wall 130 of the cell 100, the first protective film 1 covers the upper surface 131, the second protective film 2 covers the lower surface 132, and the first overlapping portion 11 is attached to the outer wall of the second overlapping portion 21 to form an overlapping area 3. That is, the first protective film 1 covers the outer surface of the upper part 110 of the entire cell 100, and the second protective film 2 covers the outer surface of the lower part 120 of the entire cell 100. Compared with the solution of only covering the peripheral outer wall of the cell 100 in the first embodiment, the entire outer surface of the cell 100 can be completely protected, and its use safety is improved.

[0039] In this embodiment, before the first protective film 1 and the second protective film 2 are coated on the battery cell 100, the battery cell 100 is treated with plasma technology to clean the surface pollutants, improve the surface performance of the battery cell 100, and facilitate the bonding treatment of the battery cell protective film. The adhesion of the overlapping area 3 is less than the adhesion between the battery cell protective film and the battery cell 100, and the adhesion between the battery cell protective film and the battery cell 100 is less than the adhesion between the bottom of the battery cell and the cold plate structure. Therefore, after the overlapping area 3 is disconnected, the battery cell 100 can be separated from the battery cell protective film by external force to ensure that the battery cell 100 is completely removed.

[0040] Furthermore, the second protective film 2 and the lower surface 132 can be detachably attached, and there is a first adhesive force between the second protective film 2 and the lower surface 132, and there is a second adhesive force between the second protective film 2 and the thermally conductive structural adhesive, and the first adhesive force is less than the second adhesive force. Since the second protective film 2 and the lower surface 132 of the battery cell 100 have a first adhesive force, and the second protective film 2 and the thermally conductive structure have a second adhesive force, the thermally conductive structural adhesive is used to bond the bottom of the battery cell 100 to the battery pack. Since the second adhesive force is greater than the first adhesive force, the second protective film 2 can be bonded to the inside of the battery pack during the process of taking out the battery cell 100, and the battery cell 100 can be easily taken out.

[0041] like Figure 1 As shown, the first protective film 1 is provided with an avoidance hole 101. On the one hand, the avoidance hole 101 can avoid the protruding structure 140 on the upper part of the battery cell 100, such as the pole, etc.; on the other hand, it can reduce the amount of raw materials used in the first protective film 1 and reduce costs.

[0042] Preferably, a plurality of avoidance holes 101 are provided on the first protective film 1 to correspond to the plurality of protruding structures 140 on the upper portion of the battery cell 100 , and the first protective film 1 is more accurately positioned when it is sleeved on the battery cell 100 .

[0043] Embodiment 3

[0044] In the present embodiment 3, the difference from the above-mentioned embodiment 1 is that the overlap area 3 is an adhesive area, and the overlap length of the overlap area 3 is 10mm-20mm. On the one hand, the first overlap 11 and the second overlap 21 are connected by bonding, so that the first overlap 11 and the second overlap 21 have good flatness, which can improve the energy density when the battery cells 100 are connected in series into a battery module; on the other hand, no high temperature is generated during the processing, and the battery cells 100 will not be damaged. If the overlap length of the overlap area 3 is too long, the adhesion between the first overlap part 11 and the second overlap part 21 will be greater, and the overlap area 3 will not be easy to break; if the overlap length of the overlap area 3 is too short, the adhesion between the first overlap part 11 and the second overlap part 21 will be poor. Therefore, the overlapping length of the overlapping area 3 can be 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, or 20mm. In this embodiment, the overlapping length of the overlapping area 3 is 15mm.

[0045] Preferably, in the adhesive bonding area, the glue used is ordinary glue. The bonding strength of ordinary glue is low, so the overlapping area 3 is easy to disconnect, which is convenient for subsequent operations. In this embodiment, the bonding strength of ordinary glue is less than the bonding strength between the bottom plate of the battery cell 100 and the cold plate structure. Therefore, when the staff takes the battery cell 100, the overlapping area 3 is first disconnected under the action of external force, and the second protective film 2 located at the bottom of the battery cell 100 is bonded to the cold plate structure, and the battery cell 100 is separated from the second protective film 2. Therefore, it can be ensured that the battery cell 100 is completely taken out, and the battery cell 100 will not be deformed or damaged, saving the cost of the battery cell 100.

[0046] like Figure 3 As shown, in the present embodiment, the overlapping area 3 of the first protective film 1 and the second protective film 2 is a rectangle. In other embodiments, depending on the different ways in which the first protective film 1 and the second protective film 2 wrap the battery cell 100, the overlapping area 3 may be other shapes, such as a parallelogram or a curve, which is not specifically limited here.

[0047] In some embodiments, the cross section of the first protective film 1 is U-shaped; in other embodiments, the cross section of the second protective film 2 is U-shaped; in still other embodiments, the cross section of the first protective film 1 is U-shaped and the cross section of the second protective film 2 is U-shaped. In this embodiment, the cross section of the first protective film 1 and the cross section of the second protective film 2 are both U-shaped, and the first protective film 1 and the second protective film 2 are respectively sleeved on both ends of the battery cell 100 to cover the entire outer wall surface of the battery cell 100. The process is simple and easy to install.

[0048] For the convenience of processing and reducing the difficulty of processing technology, in this embodiment, the overlapping area 3 is located in the middle of the battery cell 100. In other embodiments, the overlapping area 3 can also be closer to the top of the battery cell 100, or the overlapping area 3 can also be closer to the bottom of the battery cell 100, which is not specifically limited here.

[0049] like Figure 2 As shown, the first overlapping portion 11 can be pressed and overlapped with the second overlapping portion 21. In other embodiments, the second overlapping portion 21 can also be pressed and overlapped with the first overlapping portion 11, and the processing difficulty is low.

[0050] In this embodiment, the battery cell protection film is a PET film, which has good insulation protection effect.

[0051] Embodiment 4

[0052] The fourth embodiment provides a battery pack, including a battery cell 100, a cold plate structure, and a battery cell protective film as described in any one of the first, second, and third embodiments, wherein the battery cell protective film is coated on the peripheral outer wall 130 of the battery cell 100, and the second protective film 2 coated on the bottom of the battery cell 100 is connected to the cold plate structure. When the battery cell 100 is taken out, the first protective film 1 and the second protective film 2 of the battery cell protective film can be disconnected at the overlap area 3, so that the first protective film 1 and the second protective film 2 are separated, thereby ensuring that the battery cell 100 is completely taken out, reducing the loss rate of the battery cell 100 during repair and recycling, and saving the cost of the battery cell 100.

[0053] The second protective film 2 is bonded to the cold plate structure by a heat-conducting structural adhesive, and the adhesive force of the heat-conducting structural adhesive is greater than the adhesive force of the overlapping area 3. The overlapping area 3 can be disconnected to ensure that the battery cell 100 is completely taken out.

[0054] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all implementation methods here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A battery cell protection film, used for coating the peripheral outer wall (130) of a battery cell (100), characterized in that: include: A first protective film (1), the first protective film (1) covering an upper half (110) of the battery cell (100), the first protective film (1) being provided with a first overlapping portion (11); A second protective film (2), wherein the second protective film (2) is coated on the lower half (120) of the battery cell (100), a second overlapping portion (21) is provided on the second protective film (2), and after the first protective film (1) and the second protective film (2) coat the battery cell (100), at least a portion of the first overlapping portion (11) and at least a portion of the second overlapping portion (21) overlap with each other to form an overlapping area (3); the fixing force between the first overlapping portion (11) and the second overlapping portion (21) is smaller than the bonding force between the first protective film (1) and the thermally conductive structural adhesive.

2. The battery cell protection film according to claim 1, characterized in that: The upper part (110) of the battery cell (100) has an upper surface (131), and the lower part (120) of the battery cell (100) has a lower surface (132); the upper surface (131) and the lower surface (132) form a peripheral outer wall (130) of the battery cell (100); the first protective film (1) covers the upper surface (131), and the second protective film (2) covers the lower surface (132); the first overlapping portion (11) is attached to the outer wall of the second overlapping portion (21) to form the overlapping area (3).

3. The battery cell protection film according to claim 2, characterized in that: The second protective film (2) and the lower surface (132) can be detachably bonded together, a first bonding force exists between the second protective film (2) and the lower surface (132), a second bonding force exists between the second protective film (2) and the thermally conductive structural adhesive, and the first bonding force is smaller than the second bonding force.

4. The battery cell protection film according to claim 1, characterized in that: The overlapping area (3) is an adhesive area, and the overlapping length of the overlapping area (3) is 10 mm-20 mm.

5. The battery cell protection film according to claim 1, characterized in that: The cross section of the first protective film (1) is U-shaped; and / or, The cross section of the second protective film (2) is U-shaped.

6. The battery cell protection film according to claim 1, characterized in that: The first protective film (1) is provided with an avoidance hole (101), and the avoidance hole (101) can avoid the protruding structure (140) on the upper part of the battery cell (100).

7. The battery cell protection film according to claim 6, characterized in that: The first protective film (1) is provided with a plurality of avoidance holes (101) to correspond to the plurality of protruding structures (140) on the upper part of the battery core (100).

8. The battery cell protection film according to claim 1, characterized in that: The overlapping area (3) is located in the middle of the battery core (100).

9. A battery pack, characterized in that: The invention comprises a battery cell (100), a cold plate structure and a battery cell protection film as claimed in any one of claims 1 to 8, wherein the battery cell protection film is coated on the peripheral outer wall (130) of the battery cell (100), and the second protection film (2) coated on the bottom of the battery cell (100) is connected to the cold plate structure.

10. The battery pack according to claim 9, characterized in that: The second protective film (2) is bonded to the cold plate structure by means of a heat-conducting structural adhesive, and the adhesive force of the heat-conducting structural adhesive is greater than the adhesive force of the overlapping area (3).

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