NEGATIVE ELECTRODE MATERIAL FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERY AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a negative electrode material for a nonaqueous secondary battery which is higher in discharge capacity and superior in cycle life than the negative electrode material consisting of a conventional carbon material. SOLUTION: This is a negative electrode material which consists of Si phase and a Si-containing intermetallic compound phase obtained by casting an alloy molten metal containing one kind or more elements chosen from among group 2A elements and transition elements in thin flakes by a strip casting method or a centrifugal casting method in which a columnar crystal structure occupies 10% more of the alloy cross-sectional area in the length direction of the columnar crystal on the average and in which the average minor axis grain size of the phase of the intermetallic compound except what is crystallized as eutectic in this columnar crystal structure is 100μm or less.