ACTIVE MATERIAL FOR NEGATIVE ELECTRODE

摘要

PROBLEM TO BE SOLVED: To provide an electrode for a lithium ion battery, which is superior in charge and discharge cycles.SOLUTION: An active material (B) for a negative electrode comprises porous silicon particles (A) of which the 50%-particle diameter (d50) is 10 to 1000 nm. The difference between the 90%-particle diameter (d90) of the porous silicon particles (A) and the 10%-particle diameter (d10) is preferably 10 to 500 nm. The surfaces of the porous silicon particles (A) are preferably coated with a conducting agent (D). A method for manufacturing the active material (B) for a negative electrode comprises the step of removing a supercritical or subcritical fluid (J) from a mixture (K) arranged by mixing porous silicon particles (A) of which the 50%-particle diameter (d50) is 10 to 1000 nm with a conducting agent (D) in the supercritical or subcritical fluid (J).SELECTED DRAWING: None