Negative electrode active material, negative electrode, lithium ion secondary battery, method of producing negative electrode active material, and method of producing lithium ion secondary battery

A negative electrode active material comprising

• a negative electrode active material particle having:
• (i) a peak in a range of 539 to 541 eV in a XANES spectrum that is obtained by XANES measurement of the negative electrode active material particle, and (ii) a strongest peak at the vicinity of 532 eV in the XANES spectrum;
• wherein
• the negative electrode active material particle exhibits a decrease in the strongest peak at the vicinity of 532 eV in occlusion of Li,
• the negative electrode active material particle exhibits a peak generated at the vicinity of 534 eV in the XANES spectrum in occlusion of Li, wherein
• Li is inserted into a Si—O bond to reduce at least part of Si—O bonds and to form a Li—Si bond or an O—Li bond, and
• the peak at the vicinity of 532 eV is attributable to Si—O bonds which contribute to occlusion of Li;
• and
• the negative electrode active material particle comprises a silicon compound shown by SiOx, where 0.5≤x≤1.6 wherein
• the silicon compound comprises a silicon dioxide (SiO2) component and a silicon (Si) component.