NOVELTY - A negative electrode comprises a mixture layer including a composite negative electrode active material containing active material cores (11) capable of charging and discharging lithium ions, carbon nanofibers (12) attached to surfaces of the active material cores and formed between the active material cores, and catalyst element (13) comprising copper, iron, cobalt, nickel, molybdenum or manganese, and promoting growth of the carbon nanofibers.    USE - For non-aqueous electrolyte secondary batteries for portable and cordless electronic instruments.    ADVANTAGE - A high-capacity negative electrode is provided without sacrificing battery characteristics. The negative electrode enables a battery to exhibit excellent cycle characteristics by preventing the collapse of the conductive network and thus avoiding an increase in the impedance of the negative electrode as a whole.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (a) a non-aqueous electrolyte secondary battery comprising the negative electrode, a positive electrode disposed opposite to the negative electrode, and a non-aqueous electrolyte interposed between the negative electrode and the positive electrode; and    (b) a method for producing a negative electrode for non-aqueous electrolyte secondary batteries, comprising providing catalyst element in a surface part of active material cores capable of charging and discharging lithium ions, growing carbon nanofibers on surfaces of the active material cores in an atmosphere containing carbon-containing gas and hydrogen gas to form a composite negative electrode active material, and forming a mixture layer in a manner that the carbon nanofibers are formed between the active material cores.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic diagram showing changes in composite negative electrode active material particles contained in a negative electrode for non-aqueous electrolyte secondary batteries when the composite negative electrode active material is rolled.    Active material core (11)    Carbon nanofibers (12)    Catalyst element (13)