What is the purpose of using copper foil for the negative electrode of lithium-ion battery poles and aluminum foil for the positive electrode

The working principle of the lithium ion battery is an electrochemical device that converts chemical energy into electrical energy. Then, in this process, if a medium is needed to transfer the electrical energy converted from chemical energy, a conductive material is needed. Among ordinary materials, metal materials are the most conductive materials; among the metal materials, copper foil and aluminum foil are cheap and conductive. At the same time, in lithium-ion batteries, we mainly have two processing methods: winding and lamination. Regarding winding, the pole pieces used to prepare the battery must have a certain degree of flexibility to ensure that the pole pieces do not suffer from brittleness during winding. Among the metal materials, copper aluminum foil is also a softer metal. Finally, consider the cost of battery preparation. Relatively speaking, the price of copper and aluminum foil is relatively cheap, and the world has abundant copper and aluminum element resources. 2. Stable aluminum is easy to chemically react with oxygen in the air, forming a dense oxide film on the aluminum surface layer to prevent further aluminum reaction, and this thin oxide film also has a certain effect on aluminum in the electrolyte. For protection purposes. Copper itself is relatively stable in air, and basically does not react in dry air. 3. Potential situation The positive electrode potential is high, copper foil is easily oxidized under high potential, while the oxidation potential of aluminum is high, and the surface of the aluminum foil has a dense oxide film, which also has a better protective effect on the internal aluminum. Both are used as current collectors because they have good electrical conductivity, soft texture (maybe it will also be good for bonding), and are relatively common and cheaper. At the same time, an oxide protective film can be formed on both surfaces. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: Can lithium-ion batteries be shipped by air? What are the requirements for lithium-ion battery transportation