| 摘要 |
PROBLEM TO BE SOLVED: To provide Si alloy powder for a lithium ion secondary battery negative electrode active material high in discharge capacity and excellent in cycle life, and a method for producing the Si alloy powder for a lithium ion secondary battery negative electrode active material.SOLUTION: Si alloy powder for a lithium ion secondary battery negative electrode contains, in atom%, 0.01-0.5% of C and 10-25% of one or two or more of Cr, Ti, Al and Sn in total, with the remainder being Si and unavoidable impurities, and satisfies both the following expressions (1) and (2). 0.15≤Cr%/(Cr%+Ti%+Al%+Sn%)≤1.00...(1), and (Al%+Sn%)/(Cr%+Ti%+Al%+Sn%)≤0.40...(2) |
