Copper foil of lithium battery material

According to the manufacturing process, copper foil can be divided into: electrolytic copper foil and rolled copper foil. In March 2000, the American Electronic Circuit Interconnection and Packaging Association (IPC) issued the 'Metal Foil for Printed Boards' (IPC-4562). The IPC-4562 standard is a world authoritative standard that comprehensively regulates the variety, grade and performance of copper foil. It has the world's advanced nature, and it replaces the IPC-MF-150G standard implemented by most of the original copper foil manufacturers in the world. IPC-4562 stipulates the type and code of metal foil: E-electrolytic copper foil, W-rolled copper foil. Electrodeposited copper foil refers to the copper foil made by electrodeposition (electrodepositedcopperfoil); calendered copper foil is the copper foil made by rolling method, also known as wroughtcopperfoil. At present, electrolytic copper foil is the most used in lithium-ion batteries. Electrolytic copper foil uses copper sulfate solution as a raw material, copper ions are precipitated on a rotating cathode made of titanium or stainless steel, and the precipitated copper foil is continuously peeled to make copper foil. Then solve the surface according to the requirements of use. Several definitions of electrolytic copper foil: Cathode side: refers to the side close to the cathode roller, this side is the smooth side; anode side: refers to the side that does not rely on the cathode roller, this side is generally rough. According to the later solution of copper foil, copper foil can be divided into: single-sided wool, double-sided wool and double-sided light. Single-sided hair is the copper foil obtained by straightly anti-oxidizing the electrolyzed copper foil. Double-sided wool is the foil obtained by electrolyzing the copper foil on the smooth surface of the cathode roller and then passing it through a surface treatment machine (plating with a layer of copper particles), and then through the anti-oxidation solution. Double-sided light is to solve the electrolysis of the anode rough surface through a special process to make the crystal structure of the copper foil smooth and delicate, so that the color and roughness of the surface are close to the smooth surface, and then go through anti-oxidation solution. In the early days, single-sided wool was used in lithium-ion batteries, but due to the poor consistency of both sides, the battery consistency between batches was also problematic. Therefore, most manufacturers currently use double-sided light copper foil. Furthermore, the grains of the matte surface are different from those of the smooth surface. The contact between the matte surface and the active material is point-like, and the smooth surface is in surface contact, so the impact on the internal resistance and adhesion of the battery is also different. In addition, the different crystalline structure makes the tensile strength and elongation of the smooth copper foil better than that of the matte copper foil. The key technical indicators for copper foil are: 1. Surface roughness, which is a critical parameter for adhesion, especially for oily negative electrodes; 2. Surface tension and dyne index must be small, so that the slurry can be spread evenly The surface tension is related to the surface coating elements. At present, domestic foils are basically nickel-plated and zinc-plated, so the surface tension is relatively large, but the foreign ones are chrome-plated, which has stronger oxidation resistance and higher surface tension small. Japanese foil and Taiwan foil are basically chrome plated. Others are conventional indicators, such as: 1. Thickness; 2. Area density; 3. Normal tensile; 4. Normal elongation; 5. High temperature tensile; 6. High temperature elongation; 7. Appearance. At present, the main problems of domestic copper foil are: serious inconsistency in roughness on both sides, unstable roughness between batches; insufficient surface oxidation resistance; excessive surface tension. Urgent improvement is needed. Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete.