Lithium battery cell aluminum shell surface coating insulation protection structure

Abstract

The utility model discloses a lithium battery cell aluminum shell surface coating insulation protection structure which comprises a cell aluminum shell and an insulation coating, the insulation coating comprises a ceramic material, a nanometer material and a high-molecular polymer material, and the surface of the cell aluminum shell is sequentially coated with the ceramic material, the nanometer material and the high-molecular polymer material; the ceramic material is at least one of aluminum oxide, silicon nitride, zirconium oxide and aluminum nitride; the high-molecular polymer material is preferably polyimide; the nanometer material is nanometer aluminum oxide. The mylar film has remarkable advantages in the aspects of material composition, coating process, insulating property, cost, environmental friendliness and the like, can effectively replace a traditional mylar film, and overcomes the defects in the prior art. The preparation method has the characteristics of simple process, low cost and excellent performance, and has important application value and market competitiveness in the field of electronic manufacturing.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery manufacturing technology, specifically to an insulating protective structure coated on the surface of the aluminum shell of a lithium battery cell. Background Technology

[0002] With the increasing demand for high-energy-density, long-term stable batteries in electric vehicles (such as electric cars) and portable electronic devices (such as smartphones and laptops), energy storage devices such as lithium batteries have become a core component of modern society. Lithium batteries, with their advantages of high energy density, long lifespan, and light weight, have been widely used in numerous fields. However, as the scale of battery applications expands, battery safety, stability, and durability are gradually becoming the focus of technological innovation.

[0003] In lithium-ion battery structures, the battery casing is typically made of aluminum, which not only effectively reduces weight but also provides good mechanical protection. However, due to the electrical conductivity of aluminum, an insulating layer is usually added to the surface of the aluminum casing to prevent short circuits, improve safety, and effectively isolate the battery's internal current from the external environment. The traditional solution is to use thin-film materials such as Mylar film (polyester film) to cover the battery's aluminum casing for insulation protection. However, traditional Mylar film has gradually revealed some drawbacks, especially in high-temperature, high-humidity, and long-term use environments. The film material is prone to aging, peeling, and deformation, leading to a decrease in battery safety.

[0004] Existing technical solutions:

[0005] CN201822249422.9 discloses a Mylar film structure for lithium batteries, a lithium battery assembly structure, and a lithium battery. The Mylar film structure is used to encapsulate bare cells of a prismatic lithium battery. The Mylar film structure includes a rectangular Mylar film and a base sheet connected to the Mylar film. The Mylar film includes a back cover sheet that is in close contact with the back of the bare cell. The base sheet is made of an electrically insulating material and forms a bottom cover sheet that is in close contact with the bottom of the bare cell. Two front cover sheets partially overlap and are glued together on the front side of the bare cell, and the bottom cover sheet partially overlaps and is glued to the two front cover sheets on the front side of the bare cell.

[0006] CN202420919599.8 provides a structure to improve the corrosion resistance of batteries. The Mylar film and bottom support holes are changed from a one-to-one correspondence design to a staggered design, which greatly increases the electron and ion channel paths that cause corrosion to the aluminum shell of the battery. Moreover, this design itself prevents the possibility of the electrode powder coming into contact with the aluminum shell, reduces the probability of battery corrosion and leakage, and greatly improves the safety performance of the battery.

[0007] CN202420914448.3 provides a welding apparatus and a packaging welding machine, as well as the blade battery manufactured therefrom. The welding mechanism pre-welds the side support pieces to the surface of the Mylar film, which ensures that the Mylar film covers the surface of the battery cell smoothly when the Mylar film is subsequently wrapped around the surface of the battery cell.

[0008] Existing technologies have the following drawbacks: 1) Mylar films are expensive, increasing battery production costs. 2) Mylar films require cutting and lamination processes, resulting in complex workflows and low production efficiency. 3) Mylar films have low mechanical strength, making them prone to damage during battery assembly and use, leading to insulation failure and posing safety hazards.

[0009] Therefore, it is necessary to provide an insulating protective structure for coating the aluminum shell surface of lithium battery cells. Utility Model Content

[0010] To address the problems of the existing technology, this invention provides a battery protection structure that replaces the Mylar film by coating the aluminum shell of the battery cell with an insulating material. It offers significant advantages in material composition, coating process, insulation performance, cost, and environmental friendliness, effectively replacing traditional Mylar films and overcoming the shortcomings of existing technologies. Its simple process, low cost, and excellent performance make it highly valuable and competitive in the electronics manufacturing field.

[0011] To achieve the above objectives, this utility model provides the following technical solution: an insulating protective structure for coating the surface of an aluminum shell of a lithium battery cell, comprising an aluminum shell of the cell and an insulating coating, wherein the insulating coating comprises ceramic materials, nanomaterials, and polymer materials, and the aluminum shell of the cell is sequentially coated with ceramic materials, nanomaterials, and polymer materials; wherein the ceramic material is at least one of alumina, silicon nitride, zirconium oxide, and aluminum nitride; wherein the polymer material is at least one of polyimide, polyurethane, epoxy resin, and polyethylene terephthalate; and wherein the nanomaterial is at least one of nano-alumina, nano-silicon nitride, carbon nanotubes, and graphene.

[0012] Preferably, the aluminum casing of the battery cell needs to be pretreated before the insulating coating is applied; the pretreatment is preferably carried out by at least one of alkaline washing, acid washing, sandblasting, and anodizing.

[0013] Preferably, the coating method is at least one of spraying, dip coating, spin coating or chemical vapor deposition.

[0014] Preferably, the solid content of the insulating coating is 10% to 50%, and the viscosity is 10 to 1000 mPa·s; the curing temperature is 100 to 300°C, and the curing time is 10 to 120 minutes.

[0015] Preferably, the ceramic material is selected by curing at 200°C for 60 minutes to form an alumina ceramic coating; the polymer material is selected by polyimide composite material; the nanomaterial is selected by nano-alumina material; both the nanomaterial and the polymer material are cured at 250°C for 90 minutes to form a nano-alumina coating and a polyimide composite coating.

[0016] In summary, this utility model provides an insulating protective structure for coating the aluminum shell surface of a lithium battery cell. Compared with the prior art, the advantages of this utility model are:

[0017] 1. Low cost: The use of coated insulating material instead of Mylar film reduces material and processing costs.

[0018] 2. Simple process: The coating process is simple and easy to implement, making it easy to automate production and improving production efficiency.

[0019] 3. Excellent insulation performance: Ceramic and polymer materials have excellent insulation performance, which can effectively prevent short circuits in the battery cell.

[0020] 4. High mechanical strength: The insulating coating is firmly bonded to the aluminum shell, resulting in high mechanical strength and resistance to damage, thus improving the safety and reliability of the battery.

[0021] 5. Excellent high-temperature resistance: Ceramic materials and polymer materials have excellent high-temperature resistance, which can meet the requirements of battery use in high-temperature environments. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the insulating protection structure coated on the aluminum shell surface of the lithium battery cell of this utility model; Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings.

[0024] like Figure 1 As shown:

[0025] This utility model relates to an insulating protective structure for coating the surface of an aluminum shell of a lithium battery cell, comprising an aluminum shell of the cell and an insulating coating. The insulating coating comprises ceramic materials, nanomaterials, and polymer materials. The aluminum shell of the cell is coated with ceramic materials, nanomaterials, and polymer materials in sequence. The ceramic material is at least one of alumina, silicon nitride, zirconium oxide, and aluminum nitride. The polymer material is preferably polyimide. The nanomaterial is nano-alumina.

[0026] Preferably, the aluminum casing of the battery cell needs to be pretreated before the insulating coating is applied; the pretreatment is preferably carried out by alkaline washing and sandblasting.

[0027] Preferably, the coating method is a combination of spraying, dipping, and spin coating.

[0028] Preferably, the solid content of the insulating coating is 10% to 50%, and the viscosity is 10 to 1000 mPa·s; the curing temperature is 100 to 300°C, and the curing time is 10 to 120 minutes.

[0029] Preferably, the ceramic material is selected by curing at 200°C for 60 minutes to form an alumina ceramic coating; the polymer material is selected by polyimide composite material; the nanomaterial is selected by nano-alumina material; both the nanomaterial and the polymer material are cured at 250°C for 90 minutes to form a nano-alumina coating and a polyimide composite coating.

[0030] The specific method of coating insulation protection is as follows:

[0031] 1. First, the surface of the aluminum casing of the battery cell is treated with alkaline washing and sandblasting to remove surface oil and oxide layer;

[0032] 2. Then, the alumina powder is mixed with deionized water, dispersant, and binder, and ball-milled to prepare an alumina ceramic coating;

[0033] 3. Apply alumina ceramic coating evenly to the surface of the battery cell's aluminum casing using a spraying method;

[0034] 4. Place the coated aluminum casing of the battery cell in an oven and cure it at 200°C for 60 minutes to form an alumina ceramic coating;

[0035] 5. Nano-alumina is mixed with a solvent to prepare a nano-alumina coating;

[0036] 6. Apply nano-alumina coating evenly to the surface of the battery cell's aluminum casing using a dip-coating method;

[0037] 7. The coated aluminum casing of the battery cell is placed in an oven and cured at 250°C for 90 minutes to form a nano-alumina coating;

[0038] 8. Polyimide resin is mixed with a solvent to prepare a polyimide coating;

[0039] 6. Apply polyimide coating evenly to the surface of the alumina ceramic coating using a spin coating method;

[0040] 7. Place the coated aluminum casing of the battery cell in an oven and cure it at 250°C for 90 minutes to form a polyimide composite coating; at this point, the coating of the insulating protective structure on the surface of the lithium battery cell aluminum casing is complete.

[0041] The embodiments described in this utility model are for illustrative purposes only and do not constitute a limitation on the scope of the claims. Other substantially equivalent substitutions that can be conceived by those skilled in the art are all within the protection scope of this utility model.

Claims

1. An insulating protective structure coated on the surface of an aluminum shell for a lithium battery cell, characterized in that, The battery includes an aluminum casing for the battery cell and an insulating coating. The insulating coating comprises ceramic materials, nanomaterials, and polymer materials. The aluminum casing for the battery cell is coated with ceramic materials, nanomaterials, and polymer materials in sequence. The ceramic material is at least one of alumina, silicon nitride, zirconium oxide, and aluminum nitride. The polymer material is at least one of polyimide, polyurethane, epoxy resin, and polyethylene terephthalate. The nanomaterial is at least one of nano-alumina, nano-silicon nitride, carbon nanotubes, and graphene.

2. The insulating protective structure for coating the aluminum shell surface of a lithium battery cell according to claim 1, characterized in that, Before applying the insulating coating, the aluminum casing of the battery cell needs to undergo surface pretreatment.

3. The insulating protective structure for coating the aluminum shell surface of a lithium battery cell according to claim 2, characterized in that, The pretreatment adopts at least one of the following methods: alkaline washing, acid washing, sandblasting, and anodizing.

4. The insulating protective structure for coating the aluminum shell surface of a lithium battery cell according to claim 1, characterized in that, The coating method is at least one of the following: spraying, dip coating, spin coating, or chemical vapor deposition.

5. The insulating protective structure for coating the aluminum shell surface of a lithium battery cell according to claim 1, characterized in that, The insulating coating has a solid content of 10% to 50% and a viscosity of 10 to 1000 mPa·s; the curing temperature is 100 to 300℃ and the curing time is 10 to 120 minutes.

6. The insulating protective structure for coating the aluminum shell surface of a lithium battery cell according to claim 5, characterized in that, The ceramic material is selected and cured at 200℃ for 60 minutes to form an alumina ceramic coating; the polymer material is selected as a polyimide composite material, and the nanomaterial is selected as a nano-alumina material. Both the nanomaterial and the polymer material are cured at 250℃ for 90 minutes to form a nano-alumina coating and a polyimide composite coating.

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