Sulfate Containing Rechargeable Battery Cathode with Oxidized Surface

Abstract

A method for preparing a positive electrode material for a rechargeable lithium battery, comprising the steps of: providing a Li metal (M) oxide electroactive material, providing an inorganic oxidizing chemical compound, providing a chemical that is a Li-acceptor, mixing the Li metal (M) oxide, the oxidizing compound and the Li-acceptor, and heating the mixture at a N temperature between 200 and 800° C. in an oxygen comprising atmosphere. In an embodiment the positive electrode material comprises a Li metal (M) oxide electroactive material, and between 0.15 and 5 wt % of a LiNaSO4 secondary phase. The Li metal oxide may have the general formula Li1+a′M1−aO2, with a′<a and 0.9≦(1+a′)/(1−a)≦1.15, and M═Ni1−x−yM′xCoy, with M′═Mni−zAlz, 0≦z≦1, 0.1≦y≦0.4 and x+y≦0.5.

Dependencies are inferred from the claim text.