摘要 |
The invention covers a powderous lithium transition metal oxide having a layered crystal structure Li1+a M1-a O2~b M'k Sm with -0.03 < a < 0.06, b .congruent. 0, M being a transition metal compound, consisting of at least 95% of either one or more elements of the group Ni, Mn, Co and Ti; M' being present on the surface of the powderous oxide, and consisting of either one or more elements from (IUPAC) of the Periodic Table, each of said Group 2, 3, or 4 elements having an ionic radius between 0.7 and 1.2 Angstrom, M' however not comprising Ti, with 0.015 < k < 0.15, k being expressed in wt%, and 0.15 < m <=0.6, m being expressed in mol%. The addition M' (like Y, Sr, Ca, Zr,...) improves the performance as cathode in rechargeable lithium batteries. In a preferred embodiment a content of 250-400 ppm calcium and 0.2-0.6 mol% of sulfur is used. Particularly, a significantly lower content of soluble base and a dramatically reduced content of fine particles are achieved. Especially preferred performance is achieved if 11.5-13.5% of the metal atoms of the cathodes are divalent nickel. |