NEGATIVE ELECTRODE ACTIVE MATERIAL, PRODUCTION METHOD FOR NEGATIVE ELECTRODE ACTIVE MATERIAL, AND LITHIUM ION SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a negative electrode active material capable of increasing battery capacity and improving cycle characteristics and initial charge/discharge characteristics when used as a negative electrode active material in a lithium ion secondary battery.SOLUTION: A negative electrode active material for use in a negative electrode active material layer of a lithium secondary battery contains a silicon-based material (SiO: 0.5≤x≤1.6), and has at least two peaks in the range of 520 eV or more and 537 eV or less of a binding energy in a Si1s waveform obtained from X-ray photoelectron spectroscopy.