METHOD FOR PRODUCING NEGATIVE ELECTRODE FOR LITHIUM SECONDARY BATTERY

摘要

The lowness of the initial efficiency which is a drawback of lithium secondary batteries wherein a SiO negative electrode is used is largely made better without hindering a large initial charge capacity peculiar to the lithium secondary batteries. A fall in the cycle characteristic when the thickness of the SiO layer is made large is prevented. To realize these matters, a thin film of SiO is formed, as a negative electrode active material layer, on the surface of a current collector by vacuum evaporation or sputtering. The film is preferably formed by an ion plating process. The thickness of the SiO thin film is set to 5 µm or more. The surface roughness of the current collector is set to follows: the maximum height roughness Rz = 5.0 or more. After the formation of the thin film, the film is thermally treated in a nonoxidative atmosphere.