Negative electrode active material and method for producing the same

A negative electrode active material containing negative electrode active material particles, wherein

• the negative electrode active material particles comprise silicon compound particles each containing a silicon compound that contains oxygen,
• the silicon compound particle contains at least one of Li2SiO3 and Li2Si2O5, and
• the silicon compound particle has, in a Si K-edge spectrum obtained from a XANES spectrum:
• a peak P which is derived from the Li silicate and located near 1847 eV;
• and
• a peak Q which is gentler than the peak P and located near 1851 to 1852 eV.

A method for producing a negative electrode active material containing negative electrode active material particles, the method comprising steps of:

• preparing silicon compound particles each containing a silicon compound that contains oxygen;
• inserting Li into the silicon compound particles to incorporate at least one of Li2SiO3 and Li2Si2O5 into the silicon compound particles so as to prepare the negative electrode active material particles;
• further selecting, from the prepared negative electrode active material particles, such negative electrode active material particles each having a peak P derived from the Li silicate and located near 1847 eV and a peak Q gentler than the peak P and located near 1851 to 1852 eV in a Si K-edge spectrum obtained from XANES spectra when the prepared negative electrode active material particles are subjected to XANES measurement;
• and
• using the selected negative electrode active material particles to produce a negative electrode active material.