A negative electrode active material for a lithium ion battery having the composition formula SiaSnbNicTiyMmCz, wherein a, b, c, y, m and z represent atomic % values, wherein M is either one of more of Fe, Cr and Co, and wherein a>0, b>0, z>0, y≧0, 0≦m≦1, c>5, z+0.5*b>a and c+y>0.75*b. The process for preparing the active material comprises the steps of:—providing a mixture of elemental and/or alloyed powders of the elements in the composition SiaSnbNicTiyMmCz, and—high energy milling under non-oxidizing conditions of the powder mixture.