| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte secondary battery decreasing an expansion in charging. <P>SOLUTION: The nonaqueous electrolyte secondary battery uses a negative active material in which silicon-containing particles are covered with carbon material, and true specific gravity of the silicon-containing particle is prescribed to 1.5-2.2. By prescribing the true specific gravity of silicon-containing particle to 1.5-2.2, fine cavities present in the vicinity of the silicon crystallites absorb the expansion of the silicon crystallites in charging, and as a result, the expansion in charging is decreased. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
