| 摘要 |
PROBLEM TO BE SOLVED: To provide: Si alloy powder for lithium ion secondary battery negative electrode active material which enables the achievement of a high discharge capacity and a superior cycle life, and has a fine structure; and a method for manufacturing such Si alloy powder.SOLUTION: Si alloy powder for lithium ion secondary battery negative electrode active material consists of eutectic alloy powder including a Si phase and a CrSiphase. The Si alloy powder includes, at at%, 16-21% of Cr and Ti in total with Cr%/(Cr%+Ti%) being the range of 0.15-1.00. The Si phase and the CrSiphase each have an average thickness of 4 μm or less in the thinner widthwise direction thereof. A method for manufacturing Si alloy powder for a lithium ion secondary battery negative electrode comprises the step of rapidly cooling and solidifying a molten raw material of the Si alloy powder at a cooling rate of 100°C/s or more. |
