Negative electrode active material, negative electrode active material mixed material, negative electrode for nonaqueous electrolyte secondary batteries, lithium ion secondary battery, method for producing negative electrode active material, and method for manufacturing lithium ion secondary battery

The present invention is a negative electrode active material containing negative electrode active material particles, which is characterized in that: the negative electrode active material particles contain silicon compound particles containing a silicon compound (SiO x , wherein 0.5 ≤ x ≤ 1.6); the silicon compound particles contain lithium; and the total content of a polyphenylene compound and a polycyclic aromatic component in the negative electrode active material particles as measured by TPD-MS is from 1 ppm by mass to 4,000 ppm by mass (inclusive). Consequently, the present invention provides a negative electrode active material which is capable of improving the cycle characteristics and the initial charge and discharge characteristics if used as a negative electrode active material for a lithium ion secondary battery.