Where is the technical difficulty in the application of 6μm copper foil for power batteries?

　　Focusing on the increase in energy density, battery companies have gradually improved materials such as positive electrodes, negative electrodes, separators, conductive agents, and structural parts. Among them, the 6μm high-end lithium copper foil has gained fame under this background.

　　Focusing on the application of 6μm high-end lithium battery copper foil, many domestic power battery companies are working on key problems.

　　At present, the thickness of lithium copper foil used by power battery companies is concentrated in 8-10μm. The quiet rise of 6μm copper foil comes from a series of adjustments to new energy vehicle policies.

　　The subsidy decline has become a consensus in the industry, but the country's performance indicators for power batteries have been increasing year by year. For example, around the improvement of energy density, battery companies have gradually improved from materials such as positive electrodes, negative electrodes, separators, conductive agents, and structural parts. Among them, 6μm high-end lithium battery copper foil is famous in this context.

　　At present, CATL, BYD, Guoxuan Hi-Tech, Yinlong, Waterma, Funeng Technology, Yiwei Lithium Energy, Penghui Energy, Tafel New Energy and other power battery companies are using 6μm high-end lithium battery copper foil development A few battery companies have been able to mass produce new products.

　　From a technical point of view, the thinning of lithium battery copper foil is the development trend. So how much effect can 6μm high-end lithium copper foil play for power battery companies?

　　Data from a battery company shows that compared to the same battery cell using 8μm copper foil, the use of 6μm high-end lithium battery copper foil can increase the amount of slurry coating and the overall energy density of the cell while the volume of the cell remains unchanged. It can be increased by 5% and ultimately increase the cruising range.

　　Of course, depending on the material system of the cylinder, square, and soft package, the impact on the energy density of the same size battery cell using 6μm copper foil will be correspondingly different. At present, many power battery companies are still in the trial test stage.

　　According to high-tech lithium battery research, power battery companies will encounter the following four major technological difficulties after adopting 6μm high-end lithium battery copper foil:

　　One is: pleating. The thickness is thinner. During the coating and stretching process of 6μm high-end lithium battery copper foil, if the roller force control accuracy is not good during coating, the copper foil is prone to wrinkles.

　　The second is: broken belt. In the battery cell process, in order to enhance the viscosity between the active material and the current collector, battery companies will use hot pressing, and finally cold pressing. In this link, the thinner 6μm copper foil is easy to break and affect the overall production rhythm and efficiency.

　　The third is high temperature oxidation. As power batteries are more sensitive to moisture, in particular, many battery companies currently use high-nickel NCM811 or even NCA materials, and the drying process and even the entire front-end cell process are demanding for dryness. Under high temperature conditions, the additives in the 6μm high-end lithium battery copper foil will be oxidized, which will affect the active function of the entire lithium battery material.

　　Fourth is that the slice is easy to fall off the powder. Die cutting is an important process in the production of power batteries, but for a long time, whether it is metal die cutting or laser die cutting, burr dust is the most difficult "crisis" in this production process. At present, not only 6μm lithium battery copper foil, but also 8μm copper foil products will still encounter such problems.

　　The industry believes that in order to solve the above four major process difficulties, in addition to strict regulation and control of process control by power battery companies, it is also closely related to the selection of various process equipment and the quality of 6μm copper foil. This requires power battery companies and upstream In-depth technical exchanges and cooperation on equipment and materials. In the context of the development of higher quality and higher energy density power batteries, close cooperation between upstream and downstream will no longer be a simple bond of interest.