Patent ID: 7482097

Claim:
An electrode active material comprising a compound of the formula Li a M 1 e M 2 f M 3 g XY 4 wherein: (a) 0<a≦2; (b) M 1 is one or more transition metals, where e>0; (c) M 2 is one or more +2 oxidation state non-transition metals, where f>0; (d) M 3 is one or more +3 oxidation state non-transition metals, where g>0, with the proviso that when M 1 is Ni or Co, M 2 is one or more +2 oxidation state non-transition metals other than Mg and Si, and M 3 is one or more +3 oxidation state non-transition metals other than Al; and (e) XY 4 is selected from the group consisting of X′O 4−x Y′ x , X′O 4−y Y′ 2y , X″S 4 , and mixtures thereof, where X′ is selected from the group consisting of P, As, Sb, Si, Ge, V, S, and mixtures thereof; X″ is selected from the group consisting of P, As, Sb, Si, Ge, V and mixtures thereof; Y′ is selected from the group consisting of halogen, S, N, and mixtures thereof; 0≦×≦3; and 0<y≦2; and wherein (e+f+g)<2, and M 1 , M 2 , M 3 , XY 4 , a, e, f, g, x, and y are selected so as to maintain electroneutrality of said compound.