摘要 |
A negative electrode active material for an electric device includes an alloy containing silicon in a range from 27% by mass to 100% by mass exclusive, aluminum in a range from 0% by mass to 73% by mass exclusive, niobium in a range from 0% by mass to 58% by mass exclusive, and inevitable impurities as a residue. The negative electrode active material can be obtained with a multi DC magnetron sputtering apparatus by use of, for example, silicon, aluminum and niobium as targets. An electric device using the negative electrode active material can achieve a high cycle property while keeping a high discharge property |