A negative
electrode material for a nonaqueous
electrolyte secondary battery having a high
discharge capacity and a good cycle life is made from
alloy particles having an average particle
diameter of 0.1-50 mum and including Si phase grains 40 and a phase of a
solid solution or an
intermetallic compound of Si and other element selected from Group 2A elements, transition elements, Group 3B elements, and Group 4B elements from the long form
periodic table (for example, an NiSi2 phase 42 and an [NiSi2+NiSi] phase 41) at least partially enveloping the Si phase grains. 5-99 wt % of this material is Si phase grains. The
alloy particles can be manufactured by rapid solidification (such as atomization or roller
quenching) of a melt including Si and the other element, or by adhering the other element to Si
powder by
electroless plating or mechanical alloying and then performing heat treatment. Even if rapid solidification is carried out, a negative
electrode material having a good
discharge capacity and cycle life is obtained without heat treatment.