| abstract |
A negative electrode material for a nonaqueous electrolyte rechargeable battery that can stably and efficiently realize a high-performance nonaqueous electrolyte rechargeable battery in which a high discharge capacity, high charge/discharge efficiency at an initial stage and during charge/discharge cycles, and excellent charge/discharge cycle properties are provided as well as electrode expansion in volume after charge/discharge cycles is suppressed. The negative electrode material for a nonaqueous electrolyte rechargeable battery in the form of particles having, at least on the surface thereof, a compound of the phase in which an element Z is present in Si in a non-equilibrium state. The compound is expressed by the general formula SiZ x M y , where Z represents C and/or N, M represents an element other than C and N, and when the concentration of the element Z in a compound Si a Z p , where each of a and p is an integer, having a composition closest to that of Si and present in an equilibrium state is presumed to be 100 atomic percent, the concentration of the element Z in the compound SiZ x M y is in the range of 10 to 95 atomic percent, and y is in the range of 0 to 0.5. |