Lithium nickel manganese cobalt composite oxide as positive electrode active material for rechargeable lithium ion batteries

A positive electrode active material powder suitable for use in a lithium ion battery, the positive electrode active material powder comprising particles of a lithium transition metal based oxide, the particles comprising a core and a surface layer on top of the core, the particles comprising the following elements: Li, M ', and oxygen, where M' has the formula: M '= NizMnyCoxAk, where A is a dopant, 0.60 < = z < = 0.86, 0 < = z < = 0.26, 0 < = z < = 0.26, 0 < = z < = 0.26, 0 < = z < = 0.26, 0 < = z < = 0.26, 0 < = z < = 0.26, 0 < = z < = 0.26, 0 < = z < = 0.26, 0 < = z < = 0.26, 0 < = z < = 0.26, 0 < = z < = 0.26, 0 < = 0.05 < = x < = 0.20, x + y + z + k = 1, and k < = 0.01, said positive electrode active material powder having a median particle size D50 in the range of 5 [mu] m to 15 [mu] m and a surface layer thickness in the range of 10 nm to 200 nm, said surface layer comprising:-sulfur in an amount greater than or equal to 0.150 wt% and less than or equal to 0.375 wt% with respect to the total weight of