Process for preparing lithium mixed metal oxides which comprise essentially lithium, manganese, cobalt and nickel as metal atoms and have a stoichiometric ratio of lithium to the total transition metals of greater than 1, which comprises a) the preparation of a mixture designated as intermediate (B) which comprises essentially lithium-comprising mixed metal hydroxides and lithium-comprising mixed metal oxide hydroxides, where manganese, cobalt and nickel are comprised in the ratio (1−a−b):a:b and the oxidation state averaged over all ions of manganese, cobalt and nickel is at least 4-1.75a-1.75b, where 0≦a≦0.5 and 0.1≦b≦0.8, by a thermal treatment carried out with continual mixing and in the presence of oxygen of a mixture (A) comprising at least one transition metal compound and at least one lithium salt (L), during which L does not melt, and b) the thermal treatment carried out without mixing and in the presence of oxygen of the intermediate (B).