NEGATIVE ELECTRODE AND NONAQUEOUS ELECTROLYTE SECONDARY BATTERY USING SAME

摘要

As a negative electrode collector, there is prepared a rolled foil, for example one having a thickness of 26 µm and composed of a rough-surfaced copper which is obtained by electrolytically depositing copper so that the surface thereof has recesses and projections. A negative electrode active material layer is formed by depositing tin (Sn) or germanium (Ge) on the rolled foil. In this connection, the deposited tin or germanium are amorphous. The arithmetical mean roughness (Ra) of the rough-surfaced rolled foil is preferably not less than 0.1 µm but not more than 10 µm. As a nonaqueous electrolyte, there is used an electrolyte obtained by adding sodium hexafluorophosphate as electrolyte salt into a nonaqueous solvent, which is obtained by mixing ethylene carbonate and diethyl carbonate at a volume ratio of 50:50, so that the concentration of the resulting is 1 mol/l.