Negative electrode active material for non-aqueous electrolyte secondary battery, negative electrode for non-aqueous electrolyte secondary battery, non-aqueous electrolyte secondary battery, and method of producing negative electrode material for non-aqueous electrolyte secondary battery

A method of producing a negative electrode material for a non-aqueous electrolyte secondary battery containing negative electrode active material particles, the method comprising:

• producing a silicon compound expressed by SiOx where 0.5≦x≦1.6;
• coating a surface of the silicon compound with a carbon coating composed of a substance at least partially containing carbon;
• selecting, from the silicon compound with the carbon coating, a silicon compound having the carbon coating with a density ranging from 1.2 g/cm3 to 1.9 g/cm3 and having a characteristic of type II or type III adsorption-desorption isotherm in the IUPAC classification as obtained by adsorption-desorption isotherm measurement with nitrogen gas;
• and
• using the selected silicon compound coated with the carbon coating as the negative electrode active material particles to produce the negative electrode material.