Anode active material for nonaqueous electrolyte secondary battery, method for producing the same, nonaqueous electrolyte secondary battery using the anode active material, and method for producing anode material for nonaqueous electrolyte secondary battery

摘要

The present invention provides a negative electrode active material for a non-aqueous electrolyte secondary battery, including negative electrode active material particles containing a silicon compound expressed by SiO x where 0.5‰¤x‰¤1.6, the silicon compound containing a lithium compound, wherein a test cell combining an electrode containing the negative electrode active material particles and a counter electrode composed of a metallic lithium exhibits a first efficiency of 82% or more, and a charge capacity of the test cell at a voltage,of the electrode of 0.17V ranges from 7% to 30% of a first discharge capacity of the test cell when the test cell is successively subjected to a constant current charge until the voltage of the electrode reaches 0.0V, a constant voltage charge until a current is decreased to one tenth of a current at the constant current charge, and a constant current discharge until the voltage of the electrode reaches 1.2V. This negative electrode active material can increase the battery capacity and improve the cycle performance.