The production of premium copper foil (thin copper foil) less than 6 micrometers (㎛) in thickness is expected to increase.
According to the industry on 13th, major Chinese copper companies such as Watson, Qinghai Electronics and Huawei Copper Foil will expand the supply of premium products below 6㎛ starting this year. Watson is the largest copper foil company in China. Qinghai Electronics produces about 1,500 tons per month of copper foils with a thickness of less than 6㎛. The company also put 5 ㎛ and 4 ㎛ products into trial production, which will be sold in the second half of this year. Huawei Copper Foil also completed the development of copper foil with less than 6㎛ and started to expand its production line. These companies produce 30,000 tons of premium copper foil annually. The amount has increased to over five times that of last year.
Copper foil should be thin with a high level of strength. As the battery energy density increases, using a thin copper foil is essential. Reducing the copper weight helps to lighten the product overall. The strength is also important as the thinness. The premium copper foil below 6㎛ has been applied to the EV battery after being applied to smartphones since the first mass production of LS Mtron, the predecessor of KCFT, in 2013. ILJIN Materials succeeded in the mass production of the products of the same specification.
Over the past few years, 10 μm and 8 μm copper foils had been used for EV batteries; however, recently, the demand for 6 μm has increased significantly. As the sales of the second-generation EVs with a maximum travel distance of 300 km or more for a one-time charge started to pick up, the demand for premium copper foils has increased. To increase the mileage, the weight of the battery must be reduced together with the battery energy density. The weight of the copper foil in the Tesla Model S reaches 30kg. If the thickness is reduced by 20%, the weight can be reduced by 6kg.
In the industry, it is expected that global copper foil production will grow 17.1 times from 91900 tons last year to 1.52 million tons in 2025. However, the number of companies that can supply a premium copper foil of 6 μm or less in large quantities steadily is less than five. This is because it is not easy to secure a high yield. As the technical difficulty increases, it takes about 1 to 1.5 year from investment to mass production.
"In general, the yield of copper foil is about 40%, and only ILJIN Materials records about 70%," said Won-Seok Jung, a researcher at Hi Investment & Securities. He added, “As the environmental regulations are strengthened, battery performance should increase, which will cause the demand for the premium copper foil to increase significantly."
Copper foil is made by electrolysis of copper sulfate solution. It is used in a large secondary battery anode collector such as EV and energy storage device (ESS).