Non-aqueous electrolyte secondary battery negative electrode material, and negative electrode and non-aqueous electrolyte secondary battery using the same

Abstract

To provide a non-aqueous electrolyte secondary battery negative electrode material that can be produced even without performing a heat treatment at a high temperature such as 2,000° C. or higher and can have the discharge capacity further increased. The non-aqueous electrolyte secondary battery negative electrode material according to the invention has a core portion including carbonaceous negative electrode active material particles; and a shell portion including a polyimide and silicon-based negative electrode active material particles and/or tin-based negative electrode active material particles. There is a feature that the value of the ratio of the volume average particle size (D50) of the silicon-based negative electrode active material particles and/or tin-based negative electrode active material particles with respect to the volume average particle size (D50) of the carbonaceous negative electrode active material particles is 0.001 to 0.1, and the content of the silicon-based negative electrode active material particles and/or tin-based negative electrode active material particles with respect to 100% by mass of the content of the carbonaceous negative electrode active material particles is 2% to 20% by mass.

Dependencies are inferred from the claim text.