The composite current collector is a composite material with raw material films such as PET as the basement membrane, and copper/aluminum molecules are stacked on both sides by vacuum coating and other processes. Using the "metal-polymer-metal" three-layer composite structure, nano-scale metal was formed on the surface of polymer PET/PP film by vacuum evaporation and magnetron sputtering, and then the metal layer was deposited by water electroplating and thickened to more than1μ m.
Guo Zai of Essence Securities165438 said in the research report released on June 7 that the current collector is the key material in lithium batteries, and the PET composite copper foil can significantly improve the safety of lithium batteries. Under the trend of thinning, PET composite copper/aluminum foil can realize the current collector with the thickness less than 8μm, which plays an important role in the lightweight of power batteries. The composite current collector has the advantages of high safety, high energy density and low cost.
Yuan Jiancong of CITIC Securities and others said in the research report released today that the composite current collector is about to usher in mass production, and 2023 is expected to become the first year of mass production. At present, the two-step technical scheme is the most mature, and the production efficiency, yield and cost will be consistent with the direction of promoting technological upgrading. Both PET and PP basement membranes have potential, among which PP has better acid resistance and may be widely used in the future. Enterprises with magnetron sputtering and water electroplating process accumulation will have the first-Mover advantage.
Chen Chuanhong of Guo Jin Securities said in the research report released on165438+June 2 that Ningde was the first to propose that the number of patents of Honeycomb Energy increased sharply in 22 years, and the layout of Guo Xuan was earlier. From the perspective of industrialization, Ningde has realized the overseas loading of anode composite aluminum foil in small batches, and cooperated with Shanxi Coal to realize mass production. Guo Xuan recently released an environmental impact assessment report, and plans to build 4 million flat current collectors (aluminum foil).
Guosen Securities Wang Weiqi and others said in the research report released in June 65438+1October 65438+July that if the consumption of 6um composite copper foil GWh battery is 234.4 tons, the global battery shipment in 2022-2025 is estimated to be 776/10931502//KLOC. According to the calculation, under the pessimistic/neutral/optimistic situation, it is estimated that the market space of 6um composite copper foil will be 5.04/100.8/2065438+600 million yuan in 2025.
The upstream of the industrial chain of composite current collector is PET substrate, magnetron sputtering equipment and water plating equipment; The middle reaches are composite copper foil production enterprises; Downstream is the power battery enterprise.
Guo said that combing the relevant participating companies and industrialization progress of the composite current collector industry chain, specifically, the upstream participating companies are mainly Double Star New Materials and Dongwei Technology; The participating enterprises in the midstream are mainly Double Star New Materials, Baoming Technology, Zhong Yi Technology, Shengli Precision, Win-Win, Wanshun New Materials and Nord. The downstream enterprises are mainly Contemporary Ampere Technology Co., Ltd., BYD and Guo Xuan Hi-Tech.
Wang Weiqi said that the overall development of composite current collectors is rapid. In terms of equipment suppliers, from August to September, 2022, Dongwei Technology signed three consecutive orders of 654.38+07 billion yuan; Zhenhua Technology is a leading enterprise of vacuum coating equipment in China. For PET substrate enterprises, Double Star New Materials has completed various processes on the basis of self-made 4.5um substrates, and has sent samples to customers at present.
PET copper foil manufacturer, Baoming Technology has invested 6 billion yuan to build Ganzhou composite copper foil base; Wanshun New Materials has developed copper mold samples and sent them to downstream customers. Jiayuan Science and Technology, Zhong Yi Science and Technology and Nord also launched the layout of composite copper foil. In addition, Lianying Co., Ltd., Shengli Precision Co., Ltd., Fangbang Co., Ltd. and Ashichuang successively laid out the manufacturing of composite copper foil.
In terms of other accessories, Guanghua Technology has provided electroplating solutions for a few domestic enterprises, and is currently accelerating the application of special chemicals for PET copper plating and the promotion of complete chemical solutions.
Citic Securities said that it recommended the most certain equipment link, the experienced composite current collector manufacturer and the potential PP basement membrane in the future. The equipment has the strongest certainty, and Dongwei Technology is recommended. It is suggested to pay attention to Jiaocheng ultrasonic (ultrasonic welding) and Sanfu Xinke (one-step method). Double-star new materials with experience in magnetic control/water electroplating are recommended for composite current collectors, and attention should be paid to Baoming Technology, Fangbang, Wanshun New Materials, Ashichuang and Chenyuan Technology. Cai Dong technology is recommended for basement membrane.
It is worth noting that the problems of composite current collector include low production efficiency and influence on battery output power. According to insiders, due to the complexity of magnetron sputtering and evaporation technology, the production efficiency and yield of composite metal foil are not as good as those of traditional foil materials. For example, magnetron sputtering has the problem of low target utilization rate, which leads to the uniformity of thin films being affected.
In addition, new processes such as transfer welding need to be added, which increases the manufacturing cost of the battery. There is a large contact resistance between PET and metal in the composite foil. At the same time, due to the introduction of flame retardant and other media, the resistance of the battery will increase and the battery power will decrease slightly.