A positive electrode active material powder suitable for lithium-ion batteries, comprising lithium transition metal-based oxide particles, said particles comprising a core and a surface layer, said surface layer being on top of said core, said particles comprising the elements: Li, a metal M′ and oxygen, wherein the metal M′ has a formula: M′=(Niz(Ni0.5Mn0.5)yCox)1-kAk, wherein A is a dopant, 0.60≤z≤0.86, 0.05≤y≤0.20, 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 ranging from 5 μm to 15 μm and a surface layer thickness ranging from 10 nm to 200 nm,
said surface layer comprising: sulfur in a content superior or equal to 0.150 wt % and inferior or equal to 0.375 wt % with respect to the total weight of the positive electrode active material powder, and aluminum in a content superior or equal to 0.05 wt % and inferior or equal to 0.15 wt % with respect to the total weight of the positive electrode active material powder, said surface layer of lithium transition metal-based oxide particles comprising a LiAlO2 phase and an LiM″1-aAlaO2 phase with M″ comprising: Ni, Mn, and Co, said LiAlO2 phase being present in the surface layer in a content superior or equal to 0.10 at % and inferior or equal to 0.30 at % with respect to the total atomic content of M′ in the positive electrode active material powder, said LiM″1-aAlaO2 phase being present in the surface layer in a content inferior to 0.14 at % with respect to the total atomic content of M′ in the positive electrode active material powder.