SILICON-CONTAINED MATERIAL, NEGATIVE ELECTRODE FOR USE IN NON-AQUEOUS ELECTROLYTE SECONDARY BATTERY, METHOD OF PRODUCING THE SAME, NON-AQUEOUS ELECTROLYTE SECONDARY BATTERY, AND METHOD OF PRODUCING THE SAME

摘要

A silicon-contained material capable of being doped with lithium and de-doped, wherein when a three-electrode cell produced by using a working electrode including the silicon-contained material as an active material, a reference electrode made of metallic lithium, a counter electrode made of metallic lithium, and an electrolyte having lithium ionic conductivity is charged and discharged to graph a relationship between a derivative of a charging or discharging capacity with respect to an electric potential of the working electrode on the basis of the reference electrode and the electric potential, a ratio B/A is 2 or less while current flows in a direction in which the lithium of the silicon-contained material is de-doped in the discharge, A being the derivative maximum value with respect to a potential range from 260 to 320 mV, and B is the derivative maximum value with respect to a potential range from 420 to 520 mV.