METHOD FOR PRODUCING NEGATIVE ELECTRODE ACTIVE MATERIAL FOR LITHIUM ION SECONDARY BATTERIES

To provide a method for producing, with high productivity, a negative electrode active material for secondary batteries that have high capacities and excellent charge and discharge characteristics, while being extremely suppressed in deterioration in charge and discharge cycles. A method for producing a negative electrode active material for lithium ion secondary batteries containing a silicon-titanium oxide composite, which is characterized in that: the silicon-titanium oxide composite contained in the negative electrode active material for lithium ion secondary batteries is obtained by coating a silicon oxide by a titanium oxide; the silicon oxide is obtained by subjecting a polymerized silsesquioxane (PSQ), which has a structure of formula (1) and is obtained by subjecting a silicon compound to hydrolysis and a condensation polymerization reaction, to a heat treatment in an inert gas atmosphere, and is represented by general formula SiOxCyHz (wherein 0.5 < x < 1.8, 0 ‰¤ y < 5 and 0 ‰¤ z < 0.4); and after coating the silicon oxide with a titanium oxide, the resulting product is subjected to a heat treatment in a reducing gas atmosphere.