| 摘要 |
PROBLEM TO BE SOLVED: To provide porous silicon particles suitable for a negative electrode material for a lithium ion battery achieving a high capacity and an excellent cycle characteristic.SOLUTION: A method for producing porous silicon particles includes: a step (a) in which a mixture formed by mixing silicon and a first element is dissolved to produce a powdery silicon alloy; a step (b) in which the powdery silicon alloy is mixed with powder of one or more second elements selected from a column of second elements described in Table 1 corresponding to the first element, and compacted at 10-1,000 MPa to obtain a green compact; a step (c) in which the green compact is heat-treated for 0.1-600 minutes at the temperature of ≥200°C and below a melting point of the second elements under an inactive atmosphere, to thereby form a silicon composite material in which silicon fine particles are dispersed in the first element and an alloy M of the second elements; and a step (d) in which the alloy M is removed from the silicon composite material. |
