NEGATIVE ELECTRODE ACTIVE MATERIAL FOR LITHIUM SECONDARY BATTERY AND NEGATIVE ELECTRODE FOR LITHIUM SECONDARY BATTERY

摘要

PURPOSE: A negative electrode active material for lithium secondary battery and negative electrode for the lithium secondary battery are provided to enhance availability ratio of theoretical capacity of active materials and cycle property. CONSTITUTION: A negative electrode active material for lithium secondary battery has 30-65 weight% of Si and has a binary matrix structure which Si-X based alloy accomplishes crystal as Si crystallite is partially coated. In the negative electrode active material for lithium secondary battery, Si crystallite is dispersed in Sn-Cu based alloy matrix which includes more than 50% of Sn. X indicates more than one element selected from Fe, Ni, and Co and more than 1 weight% of X is added to the Si-X based alloy.