7. For a rechargeable battery positive electrode material of a lithium metal oxide powder, having the general formula Li<sub>1+a</sub> M<sub>1-a</sub> O<sub>2</sub>, wherein M=Ni<sub>x</sub> Mn<sub>y</sub> Co<sub>z</sub> A<sub>v</sub>, Aas a dopant, wherein-0.05 ≤ a ≤ 0.25,0.20 ≤ x ≤ 0.90,0.10 ≤ y ≤ 0.67, and a 0.10 ≤ z ≤ 0.40, v ≤ 0.05, and the x + y + z + v=1, powder having a particle size distribution 10μm ≤ D50 ≤ 20 µm, 0.9 ≤ BET ≤ 5 has a specific surface, with BET m<sup>2</sup> /grepresented, sodium and sulfur powder also includes impurities, wherein % by weight sodium expressed by (Na<sub>weight</sub>) and sulfur (S<sub>weight</sub>) sum of the contents (2 * Na<sub>weight</sub>) +S<sub>weight</sub> more than 0.4% and less than 1.6% by weight of the weight, and wherein the molar ratio of sodium to sulfur (Na/S) was 0.4<Na/S<2.
lithium metal oxide powder
particle size distribution
10μm ≤ D50 ≤ 20 µm
µm
lithium metal oxide powder
specific surface, with BET
0.9 ≤ BET ≤ 5