Mylar membrane, battery cell assembly, battery and vehicle

Abstract

The utility model provides a Mylar membrane, battery cell subassembly, battery and vehicle relates to battery field, the Mylar membrane includes membrane body, membrane body along its thickness direction at least one side is equipped with the groove, groove along its extension direction both ends run through membrane body to form the airway. The grooves can be formed in at least one face, in the thickness direction, of the film body of the Mylar film, the two ends, in the extending direction of the grooves, of the groove penetrate through the film body to form the air channels with the two ends open, and when the multiple Mylar films are stacked, negative pressure can be prevented from being formed between every two adjacent Mylar films due to the air channels; therefore, the situation that a feeding suction nozzle of the robot sucks multiple pieces at a time during feeding is avoided, material waste is reduced, cost is reduced, the accuracy of the number of the Mylar films assembled with the battery cell can be ensured, the size of a battery cell assembly formed by the battery cell and the Mylar films is ensured to be within the design range, and the battery cell is easier to load into an aluminum shell.

Description

Technical Field

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

[0002] Before being installed in an aluminum casing, lithium-ion battery cells are typically wrapped with a layer of Mylar film (a type of polyester film) to ensure insulation between the cell and the aluminum casing, preventing contact between the cell and the casing and thus avoiding abnormal voltage at the battery side.

[0003] In related technologies, a stack of Mylar films typically consists of hundreds of sheets, piled up at the feeding position. The robot's feeding nozzle picks up the top Mylar film each time to wrap the battery cell. Because the Mylar films adhere to each other, they are prone to creating negative pressure, making it easy to pick up multiple films at once during the feeding process. This not only wastes materials and increases costs, but also increases the size of the battery cell assembly formed by the battery cell and Mylar film, making it more difficult to install into the aluminum shell. Utility Model Content

[0004] The present invention aims to solve the technical problem of feeding multiple Mylar films at once during the feeding process in related technologies.

[0005] In a first aspect, the present invention provides a Mylar membrane, comprising a membrane body, wherein at least one side of the membrane body along its thickness direction is provided with a groove, and both ends of the groove along its extension direction penetrate the membrane body to form an air passage.

[0006] Optionally, the groove is provided on one side of the membrane body along its thickness direction;

[0007] And / or, the grooves extend along the length of the membrane body, and a plurality of grooves are provided at intervals perpendicular to their extension direction.

[0008] Optionally, the groove depth is 20%-40% of the membrane body thickness.

[0009] Optionally, the membrane body includes a first PP layer, a PET layer and a second PP layer stacked sequentially, wherein the first PP layer is bonded to the PET layer and the second PP layer is bonded to the PET layer.

[0010] Optionally, the thickness of the membrane body is 0.08-0.2 mm;

[0011] And / or, the thickness ratio of the first PP layer, the PET layer and the second PP layer is 2.5:3:2.5 or 1:1:1.

[0012] Optionally, the membrane body has indentations extending along its length direction, and multiple indentations are spaced apart along the width direction of the membrane body. The membrane body is used to bend along the indentations to cover multiple sides of the battery cell.

[0013] Optionally, the membrane body has overlapping areas for mutual adhesion at both ends along its width direction, and one of the overlapping areas has a positioning hole.

[0014] Secondly, this utility model proposes a battery cell assembly, including a battery cell and the aforementioned Mylar film, wherein the Mylar film is wrapped around the outside of the battery cell.

[0015] Thirdly, this utility model proposes a battery, including the aforementioned cell assembly.

[0016] Fourthly, this utility model proposes a vehicle including the aforementioned battery.

[0017] The Mylar film, battery cell assembly, battery, and vehicle of this invention have at least the following advantages compared to related technologies:

[0018] Mylar membranes are thin sheets with relatively small thicknesses. Grooves can be formed on at least one side of the membrane body along its thickness direction, and the two ends of the grooves extend through the membrane body to form air channels with open ends. When multiple Mylar membranes are stacked, the presence of air channels creates gaps between adjacent Mylar membranes that connect to the external environment, preventing the formation of negative pressure between adjacent Mylar membranes. This avoids the robot's feeding nozzle from picking up multiple membranes at once, allowing the robot's feeding nozzle to pick up only one Mylar membrane at a time, reducing material waste and lowering costs. Furthermore, it ensures the accuracy of the number of Mylar membranes assembled with the battery cells, thereby ensuring that the size of the battery cell assembly formed by the battery cells and Mylar membranes is within the design range, making it easier to install the battery cells into the aluminum casing. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the Mylar membrane according to an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the Mylar membrane from another perspective, representing an embodiment of the present invention.

[0021] Figure 3 This is a schematic diagram of the structure of two Mylar films stacked according to an embodiment of the present invention;

[0022] Figure 4 This is a schematic diagram of the Mylar film and battery cell encapsulation structure according to an embodiment of the present invention.

[0023] Explanation of reference numerals in the attached figures:

[0024] 1. Membrane body; 11. Groove; 12. Indentation; 13. First PP layer; 14. PET layer; 15. Second PP layer; 16. Overlapping area; 17. Positioning hole; 2. Battery cell. Detailed Implementation

[0025] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0026] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fitting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0027] In addition, it should be noted that in the description of this utility model, the terms and nouns in each embodiment, such as "upper," "lower," "front," and "rear," which indicate the location, are only used to simplify the description of the positional relationship based on the accompanying drawings. They do not mean that the components and devices referred to must be operated in accordance with the specific location and limited operation, method, and structure in the specification. Such directional terms do not constitute a limitation on this utility model.

[0028] This paper establishes an XYZ coordinate system. The Z-axis represents the vertical direction, with the positive Z-axis pointing upwards and the negative Z-axis pointing downwards. It should be noted that the aforementioned Z-axis representation is merely for ease of description and simplification of this invention, and does not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation; therefore, it should not be construed as a limitation of this invention.

[0029] like Figures 1-3 As shown, a Mylar membrane according to an embodiment of the present invention includes a membrane body 1. At least one side of the membrane body 1 along its thickness direction is provided with a groove 11. Both ends of the groove 11 along its extension direction penetrate the membrane body 1 to form an air passage.

[0030] Specifically, the membrane body 1 is a thin sheet with a relatively small thickness, located in the XY plane, and can be a cuboid. At least one side of the membrane body 1 along its thickness direction has a groove 11; that is, the groove 11 can be provided on only one of the upper or lower surfaces of the membrane body 1, or grooves 11 can be provided on both the upper and lower surfaces of the membrane body 1. The groove 11 can be formed by stamping the membrane body 1. Both ends of the groove 11 extend through the membrane body 1 along its extension direction, that is, both ends of the groove 11 in the X direction extend through the membrane body 1 to form an air passage.

[0031] In this embodiment, a groove 11 can be provided on at least one side of the Mylar film body 1 along its thickness direction, and the two ends of the groove 11 along its extension direction penetrate the film body 1 to form an air passage with open ends. When multiple Mylar films are stacked, due to the presence of the air passage, there is a gap between adjacent Mylar films that is connected to the external environment, which can prevent the formation of negative pressure between adjacent Mylar films. This prevents the robot feeding nozzle from picking up multiple films at once, so that the robot feeding nozzle picks up only one Mylar film at a time, reducing material waste and helping to reduce costs. Moreover, it can ensure the accuracy of the number of Mylar films assembled with the battery cell 2, thereby ensuring that the size of the battery cell assembly composed of the battery cell 2 and the Mylar film is within the design range, making it easier for the battery cell 2 to be installed into the aluminum shell.

[0032] like Figures 1-3 As shown, optionally, the membrane body 1 has the groove 11 on one side along its thickness direction; and / or, the groove 11 extends along the length direction of the membrane body 1, and a plurality of grooves 11 are provided at intervals perpendicular to their extension direction.

[0033] Compared to providing grooves 11 on both sides of the membrane body 1 along its thickness direction, providing grooves 11 on only one side of the membrane body 1 along its thickness direction can avoid insufficient strength of the membrane body 1 due to local thickness being too small because the grooves 11 on both sides of the membrane body 1 are arranged opposite each other; moreover, providing grooves 11 on one side of the membrane body 1 can still ensure that there is a gap between adjacent Mylar membranes when multiple Mylar membranes are stacked in alignment, and negative pressure will not be formed.

[0034] The groove 11 extends along the length direction of the membrane body 1, i.e., the X-direction. The groove 11 can be of any shape, such as a rectangular groove with a uniform cross-sectional size along the X-direction, or a trapezoidal groove with a gradually increasing cross-sectional size from the positive X-axis to the negative X-axis. The length of the groove 11 along the X-direction is the same as the length of the membrane body 1 along the X-direction. Since the length direction of the membrane body 1 is consistent with the length direction of the battery cell 2 when wrapping the battery cell 2, the membrane body 1 is bent in its width direction to wrap the circumferential sidewall of the battery cell 2. In this embodiment, extending the groove 11 along the length direction of the membrane body 1 can avoid the groove 11 bending in the width direction along with the membrane body 1, thus facilitating the bending of the membrane body 1 in its width direction to wrap the circumferential sidewall of the battery cell 2. Moreover, the groove 11 is the same length as the membrane body 1, and its relatively large length can make the gap size between adjacent Mylar membranes larger, with more air, increasing the difficulty of generating negative pressure and reducing the number of grooves 11 required.

[0035] Multiple grooves 11 are spaced apart along their extension direction perpendicular to the direction of extension, that is, multiple grooves 11 are spaced apart along the width direction of the membrane body 1, such as four. This makes the gap between two adjacent Mylar membranes larger and the air more abundant during the stacking process, increasing the difficulty of generating negative pressure and ensuring that the feeding nozzle will only pick up one Mylar membrane at a time.

[0036] Optionally, the groove depth of the groove 11 is 20%-40% of the thickness of the membrane body 1. The groove depth of the groove 11 refers to the distance from the groove opening to the bottom wall of the groove, and the thickness of the membrane body 1 refers to the Z-axis dimension of the membrane body 1. Making the groove depth of the groove 11 20%-40% of the thickness of the membrane body 1 ensures that the formed air channel can accommodate more air, preventing the formation of negative pressure when Mylar membranes are stacked, and also avoids the problem that the membrane body 1 is not strong enough due to insufficient thickness at the groove 11 position, thus failing to provide good protection for the battery cell 2.

[0037] like Figure 2 As shown, optionally, the membrane body 1 includes a first PP layer 13, a PET layer 14 and a second PP layer 15 stacked sequentially, wherein the first PP layer 13 is bonded to the PET layer 14 and the second PP layer 15 is bonded to the PET layer 14.

[0038] Specifically, the first PP layer 13, the PET layer 14, and the second PP layer 15 are sequentially arranged and stacked along the Z-direction to form the film body 1. A groove 11 may be provided on the side of the first PP layer 13 and / or the second PP layer 15 away from the PET layer 14. PMMA adhesive may be thinly applied to the two surfaces of the first PP layer 13 and the PET layer 14 that are to be bonded together, so as to bond the first PP layer 13 and the PET layer 14 together; PMMA adhesive may also be thinly applied to the two surfaces of the second PP layer 15 and the PET layer 14 that are to be bonded together, so as to bond the second PP layer 15 and the PET layer 14 together.

[0039] In this embodiment, the membrane body 1 is formed by bonding three layers: a first PP layer 13, a PET layer 14, and a second PP layer 15. This ensures the puncture resistance of the membrane body 1 and provides good protection for the battery cell 2.

[0040] Optionally, the thickness of the membrane body 1 is 0.08-0.2 mm; and / or, the thickness ratio of the first PP layer 13, the PET layer 14 and the second PP layer 15 is 2.5:3:2.5 or 1:1:1.

[0041] In this embodiment, the thickness of the membrane body 1 is set in the range of 0.08-0.2mm. This can avoid the membrane body 1 being easily punctured due to its thinness, thus failing to protect the battery cell 2. It can also avoid the membrane body 1 occupying too much space inside the aluminum shell due to its excessive thickness, which would make assembly more difficult. This can save materials and reduce production costs while ensuring the puncture resistance of the membrane body 1.

[0042] The first PP layer 13 and the second PP layer 15 are both made of PP material, and the PET layer 14 is made of PET material. PP material has low density, good heat resistance and impact resistance, while PET material has good rigidity and chemical stability. By compounding the first PP layer 13, PET layer 14 and the second PP layer 15 in a ratio of 2.5:3:2.5 or 1:1:1, the resulting membrane body 1 can simultaneously achieve rigidity, density, heat and impact resistance, and chemical stability. For example, the thickness of the first PP layer 13 is 25 μm, the thickness of the PET layer 14 is 30 μm, and the thickness of the second PP layer 15 is 25 μm. A 2 μm thick layer of PMMA adhesive (PMMA is polymethyl methacrylate) is thinly coated between the first PP layer 13 and the PET layer 14, and a 2 μm thick layer of PMMA adhesive is thinly coated between the second PP layer 15 and the PET layer 14. Then the total thickness of the membrane body 1 is 84 μm, or 0.084 mm.

[0043] like Figure 1 and Figure 4As shown, optionally, the membrane body 1 is provided with indentations 12 extending along its length direction, and multiple indentations 12 are spaced apart along the width direction of the membrane body 1. The membrane body 1 is used to bend along the indentations 12 to cover multiple surfaces of the battery cell 2.

[0044] Specifically, the membrane body 1 is thinned at the indentation 12, and the depth of the indentation 12 is 30%-50% of the thickness of the membrane body 1. The membrane body 1 can be smoothly bent along the indentation 12 to facilitate wrapping the battery cell 2.

[0045] The battery cell 2 can be a cuboid structure. The battery cell 2 includes four side walls along its circumference and two end faces at both ends along its length. Four edges are formed between the four circumferential side walls. The indentation 12 extends along the length direction of the membrane body 1, that is, along the X direction. The indentation 12 can be set at intervals along the width direction of the membrane body 1. One end of the membrane body 1 along its width direction is fixed to one of the side walls of the battery cell 2, and the other end is wrapped along the circumferential side wall of the battery cell 2 and bent at the indentation 12, so that the four indentations 12 correspond exactly to the four edges of the circumferential direction of the battery cell 2, thereby completing the circumferential wrapping of the battery cell 2.

[0046] like Figure 1 and Figure 4 As shown, optionally, the membrane body 1 has overlapping areas 16 for mutual adhesion at both ends along its width direction, wherein one of the overlapping areas 16 has a positioning hole 17.

[0047] Here, overlapping areas 16 for bonding can be provided at both ends of the membrane body 1 along its width direction. The membrane body 1 wraps around the circumference of the battery cell 2 until the overlapping areas 16 at both ends are bonded together. By setting the overlapping areas 16, the wrapping effect of the membrane body 1 on the battery cell 2 can be improved, ensuring the insulation between the battery cell 2 and the aluminum shell. Positioning holes 17 can be set at the overlapping area 16 at one end of the membrane body 1. When the membrane body 1 wraps around the battery cell 2 so that the overlapping areas 16 at both ends are bonded, the positioning holes 17 can be sealed, ensuring the insulation effect between the battery cell 2 and the aluminum shell.

[0048] The positioning hole 17 can be a circular hole, and two positioning holes 17 can be provided. The feeding platform is provided with positioning posts that cooperate with the positioning holes 17. Several Mylar films are stacked neatly and are respectively fitted onto the positioning posts through the corresponding positioning holes 17 to achieve the positioning of these Mylar films and prevent the feeding nozzle from moving other Mylar films when it picks up the top Mylar film.

[0049] Another embodiment of this utility model provides a battery cell assembly, including a battery cell 2 and the aforementioned Mylar film, wherein the Mylar film is wrapped around the outside of the battery cell 2. The advantages of this battery cell assembly compared to related technologies are the same as those of the aforementioned Mylar film, and will not be repeated here.

[0050] Another embodiment of this utility model provides a battery including the aforementioned cell assembly. The battery also includes an aluminum casing and a cover plate. The cell assembly is placed inside the aluminum casing from its open end, and the cover plate covers the open end of the aluminum casing. The advantages of this battery compared to related technologies are the same as those of the aforementioned cell assembly, and will not be repeated here.

[0051] Another embodiment of this utility model provides a vehicle including the aforementioned battery. The vehicle can be a new energy vehicle. The advantages of this vehicle compared to related technologies are the same as those of the aforementioned battery, and will not be repeated here.

[0052] Although the present invention has been disclosed above, its protection scope is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the protection scope of the present invention.

Claims

1. A Mylar film characterized in that, The Mylar film comprises a film body (1), at least one side of the film body (1) is provided with a groove (11) along the thickness direction of the film body (1), the groove (11) penetrates the film body (1) at both ends along the extending direction of the groove (11) to form an air channel.

2. The Mylar film as claimed in claim 1, wherein, The film body (1) is provided with the groove (11) on one side along the thickness direction of the film body (1); And / or, the groove (11) extends along the length direction of the film body (1), and the groove (11) is provided with a plurality of grooves (11) at intervals along the direction perpendicular to the extending direction of the groove (11).

3. The Mylar film as claimed in claim 1, wherein, The groove depth of the groove (11) is 20%-40% of the thickness of the film body (1).

4. The Mylar film as claimed in claim 1, wherein, The film body (1) comprises a first PP layer (13), a PET layer (14) and a second PP layer (15) which are sequentially stacked, the first PP layer (13) and the PET layer (14) are adhesively connected, and the second PP layer (15) and the PET layer (14) are adhesively connected.

5. The Mylar film as claimed in claim 4, wherein, The thickness of the film body (1) is 0.08-0.2mm; And / or, the thickness ratio of the first PP layer (13), the PET layer (14) and the second PP layer (15) is 2.5:3:2.5 or 1:1:

1.

6. The Mylar film as claimed in claim 1, wherein, The film body (1) is provided with an indentation (12) extending along the length direction of the film body (1), a plurality of the indentations (12) are provided at intervals along the width direction of the film body (1), and the film body (1) is used for being bent along the indentation (12) to coat a plurality of surfaces of an electric core (2).

7. The Mylar film as claimed in claim 1, wherein, The film body (1) is respectively provided with overlapping areas (16) for mutual adhesion at both ends along the width direction of the film body (1), and one of the overlapping areas (16) is provided with a positioning hole (17).

8. An electrochemical cell assembly, characterized by, The Mylar film comprises an electric core (2) and the Mylar film as claimed in any one of claims 1-7, and the Mylar film is wrapped outside the electric core (2).

9. A battery, characterized by The electric core assembly comprises the electric core assembly as claimed in claim 8.

10. A vehicle characterized by comprising: The battery comprises the battery as claimed in claim 9.

Images