Composite shell structure of lithium ion battery
By designing a composite shell structure, a multi-layer structure is adopted to enhance the mechanical strength and heat insulation performance of the lithium-ion battery shell, improve insulation performance, solve the problem of insufficient safety of traditional lithium-ion batteries, and achieve higher safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- XIAOGAN CORNEX NEW ENERGY INNOVATION TECHNOLOGY CO LTD
- Filing Date
- 2025-04-24
- Publication Date
- 2026-05-01
AI Technical Summary
Traditional lithium-ion batteries suffer from insufficient mechanical strength, poor heat insulation, and poor electrical insulation properties in their casings, resulting in inadequate safety.
The composite shell structure includes a first support layer, a flame-retardant layer, and a first insulation layer. The first insulation layer is located on the inner side, and the flame-retardant layer is located in the first support layer. The multi-layer structure enhances mechanical strength and thermal insulation performance, while also improving insulation performance.
It enhances the mechanical strength, heat insulation, and electrical insulation properties of the lithium-ion battery casing, thereby improving the safety of the lithium-ion battery.
Smart Images
Figure CN224191035U_ABST
Abstract
Description
A composite casing structure for lithium-ion batteries Technical Field
[0001] This utility model relates to the field of new energy battery technology, and in particular to a composite lithium-ion battery.
[0002] Shell structure. Background Technology
[0003] Lithium-ion batteries, also known as lithium-ion batteries, are rechargeable batteries that use the movement of lithium ions between the positive and negative electrodes to complete the charging and discharging process. Lithium-ion batteries have advantages such as high energy density, high discharge power, long cycle life, no memory effect, and environmental friendliness. Due to their excellent performance, they have become an indispensable energy storage solution in modern life and are widely used in electric vehicles, backup power systems, and microgrid energy storage systems.
[0004] Lithium-ion batteries typically consist of a core, electrolyte, casing, and cover. Traditional lithium-ion battery casings often use a single-layer metal structure (such as aluminum alloy), which presents the following problems: 1. Insufficient mechanical strength: The casing is easily deformed under external pressure, leading to excessive compression of the internal electrodes and potentially causing a short circuit in the lithium-ion battery; 2. Poor thermal insulation: In the event of thermal runaway in the battery module, it can easily spread, increasing the risk of thermal runaway; 3. Poor insulation performance: The metal casing is in direct contact with the electrolyte, potentially causing leakage or potential corrosion leakage. Summary of the Invention
[0005] The purpose of this invention is to address the shortcomings of the prior art by providing a composite casing structure for lithium-ion batteries that enhances the mechanical strength, heat insulation, and electrical insulation properties of the lithium-ion battery casing, thereby ensuring the safety of the lithium-ion battery.
[0006] This utility model proposes a composite casing structure for a lithium-ion battery, including a side plate surrounding the perimeter and a bottom plate disposed at the bottom of the side plate. The side plate and the bottom plate form a cavity for loading a winding core, and the top of the cavity is open. The side plate includes a first support layer, a flame-retardant layer and a first insulating layer. The first insulating layer is disposed on the inner side, the first support layer is disposed on the outer side, and the flame-retardant layer is disposed in the first insulating layer.
[0007] Furthermore, the base plate includes a second support layer and a second insulation layer, with the second insulation layer disposed on the inner side and the second support layer disposed on the outer side.
[0008] Furthermore, the first support layer and the second support layer are an integral structure, and the first insulating layer and the second insulating layer are an integral structure.
[0009] Furthermore, a cavity is formed in the first insulating layer, and the flame-retardant layer fills the cavity.
[0010] Furthermore, the first support layer and the second support layer include a support body integrally formed by a stamping process, and an oxide film formed on the outer surface of the support body.
[0011] Furthermore, the support body is made of aluminum alloy, and the oxide film is formed by anodizing the outer surface of the support body.
[0012] Furthermore, the first insulating layer and the second insulating layer include an insulating body integrally formed by injection molding, and an insulating coating applied to the outer surface of the insulating body.
[0013] Furthermore, the insulating body is made of polyimide or polyphenylene sulfide material.
[0014] Furthermore, the insulating coating is an alumina ceramic coating or a boehmite coating.
[0015] Furthermore, the flame-retardant layer is a flame-retardant gel made of silicon-based flame-retardant material.
[0016] The composite casing structure for a lithium-ion battery proposed in this utility model has the following beneficial effects:
[0017] (1) The side panel of this composite shell structure includes a first support layer, a flame-retardant layer and a first insulation layer. The first insulation layer is disposed on the inner side, the flame-retardant layer is disposed in the first insulation layer, and the first support layer is disposed on the outer side. Thus, through the first insulation layer, the flame-retardant layer and the first support layer, the mechanical strength of the lithium-ion battery shell is enhanced, the heat insulation performance of the lithium-ion battery shell is improved, and the insulation performance of the lithium-ion battery shell is also improved, thereby ensuring the safety of the lithium-ion battery;
[0018] (2) The temperature control management device can be set on the bottom plate in this composite shell structure. Therefore, the bottom plate with a smaller cross-sectional area includes a second support layer and a second insulation layer, and the side plate with a larger cross-sectional area includes a first support layer, a flame retardant layer and a first insulation layer, thereby maximizing the mechanical strength, heat insulation performance and insulation performance of the lithium-ion battery shell, and thus ensuring the safety of the lithium-ion battery.
[0019] (3) The first and second support layers of this composite shell structure both include a support body and an oxide film. The support bodies of the first and second support layers are integrally formed by stamping process. An oxide film is provided on the outer surface of the support bodies of the first and second support layers, which can improve the impact resistance of the first and second support layers and improve the insulation performance of the first and second support layers, thereby further enhancing the structural strength of the lithium-ion battery shell, improving the insulation performance of the lithium-ion battery shell, and thus ensuring the safety of the lithium-ion battery.
[0020] (4) The first and second insulating layers of this composite shell structure include an insulating body and an insulating coating. The insulating body of the first and second insulating layers is integrally formed by injection molding. An insulating coating is applied to the outer surface of the insulating body of the first and second insulating layers to further improve the insulation performance of the first and second insulating layers, thereby further improving the insulation performance of the lithium-ion battery shell and ensuring the safety of the lithium-ion battery.
[0021] (5) The composite shell structure has an interlayer cavity formed in the insulating body of the first insulating layer during integral injection molding. The flame retardant layer is filled in the interlayer cavity, so that the side plate forms a three-layer structure. The insulation performance of the side plate is improved by the first insulating layer and the heat insulation performance of the side plate is improved by the flame retardant layer, thereby ensuring the safety of the lithium-ion battery.
[0022] (6) The flame retardant layer of this composite shell structure can be a flame retardant gel made of silicon-based flame retardant material. That is, the flame retardant gel is filled in the interlayer cavity formed in the insulating body of the first insulating layer. This not only improves the heat insulation performance of the side plate and prevents thermal runaway from spreading in the battery module, but also buffers the impact generated by the outside. This not only enhances the structural strength of the lithium-ion battery shell, but also improves the heat insulation performance of the lithium-ion battery shell, thereby ensuring the safety of the lithium-ion battery. Attached Figure Description
[0023] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the present invention. In these drawings, similar reference numerals are used to denote similar elements.
[0024] Figure 1 is a cross-sectional schematic diagram of a composite shell structure of a lithium-ion battery according to an embodiment of the present invention;
[0025] Figure 2 is an enlarged view of point A in Figure 1;
[0026] Figure 3 is a partial structural schematic diagram of the first and second support layers of a composite shell structure for a lithium-ion battery according to an embodiment of the present invention.
[0027] Figure 4 is a partial structural diagram of the first and second insulating layers of a composite shell structure for a lithium-ion battery according to an embodiment of the present invention.
[0028] In the figure: 1. Side plate; 11. First support layer; 111. Support body; 112. Oxide film; 12. Flame retardant layer; 13. First insulation layer; 131. Insulation body; 132. Insulation coating; 133. Interlayer cavity; 2. Bottom plate; 21. Second support layer; 22. Second insulation layer; 3. Cavity. Detailed Implementation
[0029] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.
[0030] Please refer to Figures 1 to 4. A composite housing structure of a lithium-ion battery according to an embodiment of the present invention includes a side plate 1 surrounding the perimeter and a bottom plate 2 disposed at the bottom of the side plate 1. The side plate 1 and the bottom plate 2 form a cavity 3 for loading the core. The top of the cavity 3 is open. The side plate 1 includes a first support layer 11, a flame retardant layer 12 and a first insulating layer 13. The first insulating layer 13 is disposed on the inner side, the first support layer 11 is disposed on the outer side, and the flame retardant layer 12 is disposed in the first insulating layer 13.
[0031] In this application, the composite housing structure includes a side plate 1 and a bottom plate 2. The side plate 1 is arranged in a circle to form two large surfaces and two side surfaces of the lithium-ion battery housing. The bottom plate 2 is located at the bottom of the side plate 1 to form the bottom surface of the lithium-ion battery housing. Thus, the side plate 1 and the bottom plate 2 enclose a cavity 3 with a top opening, allowing the core to be placed in the cavity 3 through the opening at the top of the cavity 3, thereby loading the core into the lithium-ion battery housing.
[0032] Existing lithium-ion battery casings typically use a single-layer metal structure, such as aluminum alloy casings, which have the following problems: 1. Insufficient mechanical strength: The casing is easily deformed when subjected to external pressure, leading to excessive compression of the internal electrodes and causing a short circuit in the lithium-ion battery; 2. Poor thermal insulation performance: When thermal runaway occurs in the battery module, it can easily lead to the spread of thermal runaway, thereby increasing the risk of battery thermal runaway; 3. Poor insulation performance: The metal casing is in direct contact with the electrolyte, which may cause leakage or potential corrosion leakage.
[0033] In this application, the side plate 1 of the composite shell structure includes a first support layer 11, a flame retardant layer 12 and a first insulating layer 13. The first insulating layer 13 is disposed on the inner side, the first support layer 11 is disposed on the outer side, and the flame retardant layer 12 is disposed in the first insulating layer 13. Through the composite multi-layer structure, the structural strength of the side plate 1 is increased, thereby enhancing the mechanical strength of the lithium-ion battery shell.
[0034] Furthermore, in this application, the side panel 1 includes a first support layer 11, a flame-retardant layer 12, and a first insulating layer 13. The first insulating layer 13 is disposed on the inner side, the flame-retardant layer 12 is disposed within the first insulating layer 13, and the first support layer 11 is disposed on the outer side. The first insulating layer 13 enhances the insulation performance of the side panel 1, the flame-retardant layer 12 enhances the heat insulation performance of the side panel 1, and the first support layer 11 enhances the structural strength of the side panel 1. This enhances both the mechanical strength and heat insulation performance of the lithium-ion battery casing, thereby ensuring the safety of the lithium-ion battery.
[0035] In this embodiment, the base plate 2 includes a second support layer 21 and a second insulating layer 22, wherein the second insulating layer 22 is disposed on the inner side and the second support layer 21 is disposed on the outer side. The second insulating layer 22 enhances the insulation performance of the base plate 2, and the second support layer 21 enhances the structural strength of the base plate 2, thereby enhancing both the mechanical strength and insulation performance of the lithium-ion battery casing, and thus ensuring the safety of the lithium-ion battery.
[0036] Since side plate 1 forms a circumference, creating two large surfaces and two side surfaces of the outer casing, and bottom plate 2 forms the bottom surface of the outer casing, the cross-sectional area of side plate 1 is much larger than that of bottom plate 2. A temperature control management device is typically also required on the lithium-ion battery casing to manage the temperature of the winding core within the casing during charging and discharging, ensuring it operates at a suitable temperature and guaranteeing the charging and discharging performance of the lithium-ion battery.
[0037] In this application, the temperature control management device can be set on the base plate 2. Therefore, the base plate 2 with a smaller cross-sectional area includes a second support layer 21 and a second insulating layer 22, and the side plate 1 with a larger cross-sectional area includes a first support layer 11, a flame retardant layer 12 and a first insulating layer 13, thereby maximizing the mechanical strength, heat insulation performance and insulation performance of the lithium-ion battery shell, and thus ensuring the safety of the lithium-ion battery.
[0038] In this embodiment, the first support layer 11 and the second support layer 21 are an integral structure, and the first insulating layer 13 and the second insulating layer 22 are an integral structure. In this application, the first support layer 11 of the side plate 1 and the second support layer 21 of the bottom plate 2 are configured as an integral structure, and the first insulating layer 13 of the side plate 1 and the second insulating layer 22 of the bottom plate 2 are configured as an integral structure. This enhances both the structural strength of the lithium-ion battery casing and the insulation performance of the lithium-ion battery casing, thereby ensuring the safety of the lithium-ion battery.
[0039] Furthermore, in this embodiment, the first support layer 11 and the second support layer 21 include a support body 111 integrally formed by a stamping process, and an oxide film 112 formed on the outer surface of the support body 111. In this application, both the first support layer 11 and the second support layer 21 include a support body 111 and an oxide film 112. The support body 111 of the first support layer 11 and the second support layer 21 is integrally formed by a stamping process, thereby enhancing the structural strength of the side plate 1 and the bottom plate 2, and further enhancing the structural strength of the lithium-ion battery casing.
[0040] An oxide film 112 is provided on the outer surface of the support body 111 of the first support layer 11 and the second support layer 21. The oxide film 112 can improve the impact resistance of the first support layer 11 and the second support layer 21, and also improve the insulation performance of the first support layer 11 and the second support layer 21, thereby further enhancing the structural strength of the lithium-ion battery shell, improving the insulation performance of the lithium-ion battery shell, and thus ensuring the safety of the lithium-ion battery.
[0041] Specifically, in actual implementation, the support body 111 of the first support layer 11 and the second support layer 21 can be integrally stamped from aluminum alloy material. By anodizing the outer surface of the support body 111 made of aluminum alloy material, an oxide film 112 is formed on the outer surface of the support body 111 of the first support layer 11 and the second support layer 21.
[0042] Furthermore, in this embodiment, the first insulating layer 13 and the second insulating layer 22 include an insulating body 131 integrally formed by injection molding, and an insulating coating 132 coated on the outer surface of the insulating body 131. In this application, the first insulating layer 13 and the second insulating layer 22 include an insulating body 131 and an insulating coating 132. The insulating body 131 of the first insulating layer 13 and the second insulating layer 22 is integrally formed by injection molding, thereby improving the insulation performance of the side plate 1 and the bottom plate 2, and thus improving the insulation performance of the lithium-ion battery casing.
[0043] An insulating coating 132 is applied to the outer surface of the insulating body 131 of the first insulating layer 13 and the second insulating layer 22. The insulating coating 132 further enhances the insulation performance of the first insulating layer 13 and the second insulating layer 22, thereby further enhancing the insulation performance of the lithium-ion battery casing and ensuring the safety of the lithium-ion battery.
[0044] Specifically, in actual implementation, the insulating body 131 of the first insulating layer 13 and the second insulating layer 22 can be made of insulating materials such as polyimide or polyphenylene sulfide, and integrally injection molded through nano-injection molding process. The insulating coating 132 can be an alumina ceramic coating or boehmite coating coated on the outer surface of the insulating body 131 of the first insulating layer 13 and the second insulating layer 22, thereby preventing the formation of an electronic channel between the core and the lithium-ion battery casing, avoiding corrosion of the lithium-ion battery casing, causing thermal runaway of the lithium-ion battery, and thus ensuring the safety of the lithium-ion battery.
[0045] In this embodiment, a cavity is formed in the first insulating layer 13, and the flame-retardant layer 12 fills the cavity. In this application, a cavity is formed in the insulating body 131 of the first insulating layer 13 by integral injection molding, and the flame-retardant layer 12 is filled in the cavity, so that the side plate 1 forms a three-layer structure. The insulation performance of the side plate 1 is improved by the first insulating layer 13, and the heat insulation performance of the side plate 1 is improved by the flame-retardant layer 12, thereby ensuring the safety of the lithium-ion battery.
[0046] Specifically, in this actual implementation, the flame-retardant layer 12 can be a flame-retardant gel made of silicon-based flame-retardant materials, such as methyl orthosilicate (TMOS) or tetraethyl orthosilicate (TEOS). That is, the flame-retardant gel is filled in the interlayer cavity formed in the insulating body 131 of the first insulating layer 13. This not only improves the heat insulation performance of the side plate 1 and prevents the spread of thermal runaway in the battery module when the core experiences thermal runaway, but also buffers the impact generated when the lithium-ion battery shell is impacted by the outside. Thus, it not only enhances the structural strength of the lithium-ion battery shell, but also improves the heat insulation performance of the lithium-ion battery shell, thereby ensuring the safety of the lithium-ion battery.
[0047] The above-described contents can be implemented individually or in combination in various ways, and all such variations are within the protection scope of this utility model.
[0048] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.
[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.
Claims
1. A composite casing structure for a lithium-ion battery, characterized in that: It includes a side plate (1) that surrounds the perimeter and a bottom plate (2) located at the bottom of the side plate (1). The side plate (1) and the bottom plate (2) form a cavity (3) for loading the core. The top of the cavity (3) is open. The side plate (1) includes a first support layer (11), a flame retardant layer (12) and a first insulation layer (13). The first insulation layer (13) is located on the inner side, the first support layer (11) is located on the outer side, and the flame retardant layer (12) is located in the first insulation layer (13).
2. The composite casing structure of a lithium-ion battery as described in claim 1, characterized in that: The base plate (2) includes a second support layer (21) and a second insulation layer (22), with the second insulation layer (22) located on the inner side and the second support layer (21) located on the outer side.
3. The composite casing structure of a lithium-ion battery as described in claim 2, characterized in that: The first support layer (11) and the second support layer (21) are an integral structure, and the first insulating layer (13) and the second insulating layer (22) are an integral structure.
4. The composite casing structure of a lithium-ion battery as described in claim 1, characterized in that: A cavity (133) is formed in the first insulating layer (13), and the flame retardant layer (12) fills the cavity (133).
5. The composite casing structure of a lithium-ion battery as described in claim 3, characterized in that: The first support layer (11) and the second support layer (21) include a support body (111) integrally formed by stamping process, and an oxide film (112) formed on the outer surface of the support body (111).
6. The composite casing structure of a lithium-ion battery as described in claim 5, characterized in that: The support body (111) is made of aluminum alloy, and the oxide film (112) is formed by anodizing the outer surface of the support body (111).
7. The composite casing structure of a lithium-ion battery as described in claim 3, characterized in that: The first insulating layer (13) and the second insulating layer (22) include an insulating body (131) integrally formed by injection molding process, and an insulating coating (132) coated on the outer surface of the insulating body (131).
8. The composite casing structure of a lithium-ion battery as described in claim 7, characterized in that: The insulating body (131) is made of polyimide or polyphenylene sulfide material.
9. The composite casing structure of a lithium-ion battery as described in claim 7, characterized in that: The insulating coating (132) is an alumina ceramic coating or a boehmite coating.
10. The composite casing structure of a lithium-ion battery as described in claim 4, characterized in that: The flame retardant layer (12) is a flame retardant gel made of silicon-based flame retardant material.