摘要 |
A negative electrode active material for an electric device includes an alloy containing Si in a range from 23% to 64% exclusive, Sn in a range from 4% to 58% inclusive, Zn in a range from 0% to 65% 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, tin and zinc as targets. An electric device such as a lithium ion secondary battery employing the negative electrode active material can improve cycle life of the battery and ensure a high capacity and high cycle durability. |