Battery shell with composite membrane

Abstract

The utility model relates to the technical field of lithium ions, in particular to a battery shell with a composite membrane, the battery shell is of a hollow structure with a containing cavity formed by connecting a plurality of supporting parts in a surrounding mode, at least one supporting part comprises a frame and the composite membrane, a reinforcing structure is arranged in the frame, and the composite membrane is arranged in the frame. A hollowed-out area is formed between the frame and the reinforcing structure, and the composite film covers the hollowed-out area. The utility model aims to overcome the defect that a metal shell of a square-shell battery in the prior art is heavy, and provides the battery shell which is applied to the square-shell battery, so that the weight of the battery shell can be reduced, and meanwhile, the battery shell has better safety performance.

Description

Technical Field

[0001] This utility model relates to the field of lithium-ion battery technology, and more specifically, to a battery casing with a composite film. Background Technology

[0002] Lithium-ion batteries are efficient, rechargeable energy storage devices widely used in modern electronic devices and electric vehicles. Common types of lithium-ion batteries include prismatic, cylindrical, and pouch batteries, each with its own advantages. Prismatic batteries typically use a square metal casing, often made of aluminum alloy or stainless steel, offering high safety and impact resistance. Cylindrical batteries are similar to prismatic batteries, also using a metal casing, but their safety is slightly lower. Pouch batteries, on the other hand, use an aluminum-plastic film for flexible packaging, resulting in lower safety performance and a higher susceptibility to expansion and leakage.

[0003] The metal casing of existing prismatic batteries is relatively heavy, making it difficult to fully meet the lightweight requirements of new batteries. Although aluminum-plastic film has the advantage of being lightweight, its relatively weak mechanical strength and susceptibility to external impacts limit its widespread use in prismatic battery casings that require high strength. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the large weight of the metal casing of square-shell batteries in the prior art, and to provide a battery casing with a composite film that can be applied to square-shell batteries, thereby reducing the weight of the battery casing while providing better safety performance.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0006] A battery housing with a composite membrane is provided. The battery housing is formed by multiple support parts connected and surrounding to form a hollow structure with a receiving cavity. At least one support part includes a frame and a composite membrane. A reinforcing structure is provided within the frame. A hollow area is formed between the frame and the reinforcing structure. The composite membrane covers the hollow area.

[0007] This invention comprises multiple supporting parts connected sequentially to form a regular geometric shape, such as a hexahedron, specifically a cube or cuboid. The battery casing is hollow, with a cavity for holding the battery solution. Taking a prismatic battery as an example, conventional battery casings are made of metal, resulting in significant weight. This invention replaces one or more of the sides forming the cube or cuboid (the aforementioned supporting parts) with a structure combining a frame and a composite membrane. Replacing the solid metal material in non-stressed areas of the battery casing significantly reduces its weight. A reinforcing structure is incorporated within the overall frame, providing necessary mechanical strength and support to ensure the battery casing's strength. The composite membrane seals the casing, preventing leakage of the battery solution. This design reduces the weight of the battery casing while ensuring its safety. This battery casing is applicable not only to prismatic batteries but also to batteries of other shapes.

[0008] Furthermore, the edges of the composite membrane are sealed to the frame, and the composite membrane is also connected to a reinforcing structure. The composite membrane completely covers the frame; specifically, it is sealed to the frame through its edges, while the middle portion of the composite membrane, except for the edges, is connected to the reinforcing structure to increase strength.

[0009] Furthermore, the reinforcing structure includes a plurality of reinforcing beams, which are sequentially arranged and connected at both ends to the frame. The composite membrane is connected to both the frame and the reinforcing beams. The reinforcing beams provide support to enhance the strength of the frame and meet the strength and support requirements of the battery casing.

[0010] Furthermore, the reinforcing structure also includes several reinforcing ribs, each with its two ends connected to the frame and the reinforcing beam, or each with its two ends connected to two adjacent reinforcing beams. The composite membrane is connected to the frame, the reinforcing beams, and the reinforcing ribs. The reinforcing ribs connect adjacent reinforcing beams together, increasing the overall strength. The reinforcing beams and ribs together enhance the strength of the frame structure to meet the strength and support requirements of the battery casing. The composite membrane covers the perforated areas to prevent leakage of the battery solution in the cavity.

[0011] Furthermore, several of the reinforcing beams are arranged in parallel, and the spacing between two adjacent reinforcing beams satisfies the following formula: L ≤ 0.8 × εy × t, where L is the spacing between two adjacent reinforcing beams, εy is the yield strain of the composite membrane, and t is the thickness of the composite membrane. By specifically setting the spacing of the reinforcing beams according to the characteristics of the composite membrane itself, the tensile force borne by the composite membrane can be reduced, further improving the supporting performance of the composite membrane. This optimizes the structure of the battery casing, increases the safety of the battery casing, and extends its service life.

[0012] Furthermore, the width of the reinforcing beam is 2mm to 100mm, and the thickness is 0.1mm to 10mm. This configuration further enhances the supporting performance of the reinforcing beam. To the knowledge of those skilled in the art, other widths and thicknesses can also be used for the reinforcing beam.

[0013] Furthermore, the reinforcing rib is inclined at an angle α to the reinforcing beam. The inclined reinforcing rib is a topologically optimized structure, which enables the combination of the reinforcing rib and the reinforcing beam to have optimal support performance, forming a stress-dispersing structure and reducing deformation and fracture.

[0014] Furthermore, the tilt angle α is between 15° and 30°. Preferably, the tilt angle α is 25°. This setting can further improve the connection effect of the reinforcing rib and increase the reliability of the reinforced structure after the reinforcing rib is connected to the reinforcing beam.

[0015] Furthermore, the composite membrane is heat-fused or bonded to the frame, the reinforcing beam, and the reinforcing rib. The heat-fused or bonded composite membrane provides a better seal to prevent leakage of the battery solution within the containment cavity.

[0016] Furthermore, the area of ​​the hollowed-out region accounts for 50%-95% of the area of ​​the corresponding support portion of the frame. This arrangement ensures that the frame and reinforcing structure support the composite membrane, and that the support portion composed of the frame, reinforcing structure, and composite membrane has superior support performance, thus ensuring the safety of the battery casing. To the knowledge of those skilled in the art, the combination of the frame and reinforcing structure can also be achieved by hollowing out a single support plate to form the hollowed-out region.

[0017] Furthermore, both the support and the frame are made of metal; the composite film is an aluminum-plastic composite film. Preferably, the reinforcing beams and ribs in the reinforcing structure are also made of the same metal material as the support plate and frame to improve support performance. The aluminum-plastic film, when used in battery casings, offers advantages such as light weight, high design flexibility, and simple processing.

[0018] Furthermore, the metal material is aluminum alloy or stainless steel. Aluminum alloy or stainless steel, when used in the battery casing, offers superior strength and hardness, resulting in better support performance.

[0019] Furthermore, the surface of the composite membrane is coated with a nano-coating. Coating the composite membrane with a nano-coating improves its wear resistance and puncture resistance. Specifically, the nano-coating is coated on the inner side of the composite membrane near the receiving cavity to reduce wear from the battery solution.

[0020] Compared with the prior art, the beneficial effects of this utility model are:

[0021] (1) Lightweight: It can reduce the use of metal materials, significantly reduce battery weight, and increase energy density.

[0022] (2) Cost optimization: Composite films, especially aluminum-plastic films, have lower costs than metal materials, which can reduce manufacturing costs.

[0023] (3) More flexible: The structural design is flexible and can be adapted to different specifications of square-shell batteries.

[0024] (4) More environmentally friendly: Reduces energy consumption and carbon emissions generated during metal processing, which is in line with the concept of green manufacturing. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of a battery casing with a composite film according to Embodiment 1 of the present invention;

[0026] Figure 2 This is a schematic diagram of the structure of the support portion where the composite membrane of this utility model is located;

[0027] Figure 3 This is a schematic diagram of the structure of a battery casing with a composite film according to Embodiment 2 of the present invention;

[0028] Figure 4 This is a schematic diagram of the structure of a battery casing with a composite film according to Embodiment 3 of this utility model.

[0029] The markings in the diagram are explained below:

[0030] 1. Supporting part; 2. Frame; 3. Composite membrane; 4. Reinforcing beam; 5. Reinforcing rib; α is the inclination angle between the reinforcing rib and the reinforcing beam. Detailed Implementation

[0031] The present invention will be further described below with reference to specific embodiments. The accompanying drawings are for illustrative purposes only, representing schematic diagrams rather than actual physical objects, and should not be construed as limiting the scope of this patent. To better illustrate the embodiments of the present invention, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0032] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0033] Example 1

[0034] like Figures 1 to 2 The first embodiment of the present invention is a battery housing with a composite film. The battery housing is formed by multiple support parts 1 connected and surrounding to form a hollow structure with a receiving cavity. At least one support part 1 includes a frame 2 and a composite film 3. A reinforcing structure is provided in the frame 2. A hollow area is formed between the frame 2 and the reinforcing structure. The composite film 3 covers the hollow area.

[0035] In this invention, multiple support parts 1 are sequentially connected and arranged to form a regular geometric shape, such as a hexahedron, specifically a cube or cuboid. The battery casing is hollow, with a cavity for holding the battery solution. Taking a prismatic battery as an example, conventional battery casings are made of metal and are relatively heavy. This invention replaces one or more of the sides forming the cube or cuboid (i.e., the aforementioned support parts 1) with a structure combining a frame 2 and a composite membrane 3. Replacing the solid metal material in non-stressed areas of the battery casing significantly reduces its weight. A reinforcing structure is incorporated within the overall frame 2, which, together with the frame 2, provides necessary mechanical strength and support, ensuring the strength of the battery casing. The composite membrane 3 is used for sealing and covering to prevent leakage of the battery solution in the cavity. This design reduces the weight of the battery casing while ensuring its safety. The battery casing of this invention can be used in batteries of other shapes, including but not limited to prismatic batteries. In this embodiment, the battery casing is a cuboid structure, with one side consisting of a frame 2, a reinforcing structure, and a composite membrane 3, while the other sides, as well as the top and bottom, are made of the same material.

[0036] In one embodiment of this utility model, the edge of the composite membrane 3 is sealed to the frame 2, and the composite membrane 3 is also connected to the reinforcing structure. The composite membrane 3 completely covers the frame 2; specifically, it is sealed to the frame 2 through its edge, while the middle part of the composite membrane 3, except for the edge, is connected to the reinforcing structure to increase strength. Within the understanding of those skilled in the art, the composite membrane 3 can also be placed within the area enclosed by the frame 2 and the reinforcing structure, with the edge of the composite membrane 3 sealed to both the frame 2 and the reinforcing structure.

[0037] In one embodiment of this utility model, the reinforcing structure includes a plurality of reinforcing beams 4, which are arranged sequentially and connected to the frame 2 at both ends. The composite membrane 3 is connected to both the frame 2 and the reinforcing beams 4. The reinforcing beams 4 provide support and can be arranged longitudinally or laterally to improve the strength of the frame 2 and meet the strength and support requirements of the battery casing.

[0038] The reinforcing structure also includes several reinforcing ribs 5. The two ends of each reinforcing rib 5 are connected to the frame 2 and the reinforcing beam 4, or the two ends of each reinforcing rib 5 are connected to two adjacent reinforcing beams 4. The composite membrane 3 is connected to the frame 2, the reinforcing beams 4, and the reinforcing ribs 5. The reinforcing ribs 5 connect adjacent reinforcing beams 4 together, improving the overall strength. The reinforcing beams 4 and the reinforcing ribs 5 together enhance the strength of the frame 2 structure to meet the strength and support requirements of the battery casing. The composite membrane 3 covers the perforated areas to prevent leakage of the battery solution in the containment cavity. Within the understanding of those skilled in the art, the number of reinforcing beams 4 can be set according to the length or width of the frame 2. The longer or wider the frame 2, the more reinforcing beams 4 can be set. The number of reinforcing ribs 5 can be set according to the length or height of the reinforcing beams 4. The longer or taller the frame 2, the more reinforcing ribs 5 can be set between two adjacent reinforcing beams 4. Moreover, the reinforcing ribs 5 can not only be set between two adjacent reinforcing beams 4, but also between the frame 2 and the reinforcing beams 4. When the length or width between the frames 2 is small, the reinforcing ribs 5 can be omitted, and the reinforcing beams 4 can be set directly between the frames 2 to improve the internal strength of the frame 2.

[0039] In one embodiment of this utility model, several reinforcing beams 4 are arranged in parallel, and the spacing between two adjacent reinforcing beams 4 satisfies the following formula: L≤0.8×εy×t, where L is the spacing between two adjacent reinforcing beams 4 in mm, εy is the yield strain of the composite membrane 3 in percentage (%), and t is the thickness of the composite membrane 3 in mm. By specifically setting the spacing of the reinforcing beams 4 according to the characteristics of the composite membrane 3 itself, the tensile force borne by the composite membrane 3 can be reduced, further improving the supporting performance of the composite membrane 3, thereby further optimizing the structure of the battery casing, increasing the safety of the battery casing, and extending the service life of the battery casing.

[0040] In one embodiment of this utility model, the width of the reinforcing beam 4 is 2mm to 100mm, and the thickness is 0.1mm to 10mm. This configuration further enhances the supporting performance of the reinforcing beam 4. Within the understanding of those skilled in the art, the reinforcing beam 4 can also employ other widths and thicknesses.

[0041] In one embodiment of this utility model, the reinforcing rib 5 and the reinforcing beam 4 are arranged at an inclined angle α. The inclined reinforcing rib 5 is a structure optimized by using a topological structure, which enables the combination of the reinforcing rib 5 and the reinforcing beam 4 to have optimal support performance, form a stress-dispersing structure, and reduce the occurrence of deformation and fracture.

[0042] In one embodiment of this utility model, the tilt angle α is 15° to 30°. Preferably, the tilt angle α is 25°. This setting can further improve the connection effect of the reinforcing rib 5 and increase the reliability of the reinforced structure after the reinforcing rib 5 is connected to the reinforcing beam 4.

[0043] In one embodiment of this utility model, the composite membrane 3 is connected to the frame 2, reinforcing beam 4, and reinforcing rib 5 by hot-melt welding or bonding to form an integral sealed structure. The composite membrane 3, disposed between the reinforcing beam 4, reinforcing rib 5, and frame 2, is sealed to the reinforcing beam 4, reinforcing rib 5, and frame 2 to prevent leakage of battery solution in the containment cavity.

[0044] In one embodiment of this utility model, both the support 1 and the frame 2 are made of metal; the composite film 3 is an aluminum-plastic composite film, or simply aluminum-plastic film. Preferably, the reinforcing beam 4 and reinforcing rib 5 in the reinforcing structure also use the same metal material as the support plate and frame 2 to improve the supporting performance. The aluminum-plastic film, when used in the battery casing, has advantages such as light weight, high design flexibility, and simple processing. Preferably, the metal material is aluminum alloy, stainless steel, or copper foil. The use of aluminum alloy, stainless steel, or copper foil in the battery casing provides superior strength and hardness, resulting in better supporting performance.

[0045] In one embodiment of this invention, the area of ​​the hollowed-out region occupies 50%-95% of the area of ​​the support portion 1 corresponding to the frame 2. This arrangement ensures that the frame 2 and the reinforcing structure support the composite membrane 3, and that the support portion 1, composed of the frame 2, the reinforcing structure, and the composite membrane 3, has superior support performance, thus ensuring the safety of the battery casing. Within the understanding of those skilled in the art, the combination of the frame 2 and the reinforcing structure can also be achieved by hollowing out a single support plate to form the hollowed-out region.

[0046] In one embodiment of this invention, the surface of the composite membrane 3 is coated with a nano-coating. Coating the surface of the composite membrane 3 with a nano-coating improves its wear resistance and puncture resistance. In this embodiment, the composite membrane 3 is an aluminum-plastic membrane; specifically, a nano-coating is coated on the outer side of the aluminum-plastic membrane near the receiving cavity to reduce wear from the battery solution on the composite membrane 3.

[0047] Compared with the prior art, the beneficial effects of this utility model are:

[0048] (1) Lightweight: It can reduce the use of metal materials, significantly reduce battery weight, and increase energy density.

[0049] (2) Cost optimization: Composite film 3, especially aluminum-plastic film, has a lower cost than metal materials, which can reduce manufacturing costs.

[0050] (3) More flexible: The structural design is flexible and can be adapted to different specifications of square-shell batteries.

[0051] (4) More environmentally friendly: Reduces energy consumption and carbon emissions generated during metal processing, which is in line with the concept of green manufacturing.

[0052] Example 2

[0053] like Figure 3 The following is a second embodiment of the battery casing with a composite film according to the present invention. This embodiment is similar to the first embodiment, except that the four sides of the battery casing are composed of a frame 2, a reinforcing structure and a composite film 3, and the top and bottom of the battery casing are integrally formed of metal material.

[0054] Example 3

[0055] like Figure 4 The following is a third embodiment of the battery casing with a composite film according to the present invention. This embodiment is similar to embodiment 1, except that the four sides and the top of the battery casing are composed of a frame 2, a reinforcing structure and a composite film 3, and the bottom of the battery casing is integrally formed of metal material.

[0056] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A battery case having a composite film, characterized by, The battery casing is formed by multiple support parts (1) connected around to form a hollow structure with a receiving cavity. At least one support part (1) includes a frame (2) and a composite membrane (3). A reinforcing structure is provided in the frame (2). A hollow area is formed between the frame (2) and the reinforcing structure. The composite membrane (3) covers the hollow area.

2. The battery case with a composite film according to claim 1, characterized by, The edge of the composite membrane (3) is sealed to the frame (2), and the composite membrane (3) is also connected to the reinforcing structure.

3. The battery case according to claim 2, characterized by The reinforcing structure includes several reinforcing beams (4), which are arranged sequentially and connected to the frame (2) at both ends. The composite membrane (3) is connected to the frame (2) and the reinforcing beams (4) respectively.

4. The battery case with a composite film according to claim 3, characterized by, The reinforcing structure also includes several reinforcing ribs (5), the two ends of which are connected to the frame (2) and the reinforcing beam (4) respectively, or the two ends of which are connected to two adjacent reinforcing beams (4) respectively, and the composite membrane (3) is connected to the frame (2), the reinforcing beam (4) and the reinforcing ribs (5) respectively.

5. The battery case with a composite film according to claim 3, characterized by, Several reinforcing beams (4) are arranged in parallel, and the spacing between two adjacent reinforcing beams (4) satisfies the following formula: L≤0.8×εy×t, Where L is the spacing between two adjacent reinforcing beams (4), εy is the yield strain of the composite membrane (3), and t is the thickness of the composite membrane (3).

6. The battery case with a composite film according to claim 3, characterized by, The width of the reinforcing beam (4) is 2mm to 100mm and the thickness is 0.1mm to 10mm.

7. The battery case with a composite film according to claim 4, characterized by, The reinforcing rib (5) is set at an inclined angle α with the reinforcing beam (4).

8. The battery case with a composite film according to claim 7, characterized by, The tilt angle α is 15° to 30°.

9. The battery case with a composite film according to claim 4, characterized by, The composite membrane (3) is hot-melt welded or bonded to the frame (2), the reinforcing beam (4), and the reinforcing rib (5).

10. The battery case with a composite film according to any one of claims 1 to 9, characterized by, The area of ​​the hollowed-out area accounts for 50%-95% of the area of ​​the support part (1) corresponding to the frame (2).

11. The battery case with a composite film according to claim 1, characterized by, The support (1) and the frame (2) are both made of metal; the composite film (3) is an aluminum-plastic composite film.

12. The battery case with a composite film according to claim 1, characterized by, The surface of the composite membrane (3) is coated with a nano-coating.

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