| abstract |
An object of the present invention is to provide a negative-electrode active material for lithium-ion secondary battery, negative-electrode active material which makes it possible for lithium-ion secondary batteries to exhibit higher capacities, and which makes it feasible to charge and discharge lithium-ion secondary batteries at a faster speed. In a production process according to the present invention, oxidized titanium fluoride is obtained by heating a mixed raw material, which includes a mixture of anatase-type TiO 2 and hydrofluoric acid, at 70° C. or more (i.e., a heating step). This mixed raw material includes hydrogen fluoride in an amount exceeding 2 mol per the anatase-type TiO 2 making 1 mol. When the oxidized titanium fluoride, which is obtained by this production process, is used as a negative-electrode active material of lithium-ion secondary battery, high-capacity and rapidly-chargeable/dischargeable lithium-ion secondary batteries are obtainable. |