Abstract: A process for preparing lithium-rich metal oxides. The process comprises subjecting a mixture of a metal oxide or a metal oxide with low lithium content and a lithium sulfide in a solid state to a thermal treatment to form a lithium-rich metal oxide and elemental sulfur and subliming off the elemental sulfur. The lithium-rich metal oxides produced from the process may be used as cathode material in lithium ion batteries or electrochemical cells. Suitable metal oxides may be selected from metal oxides of the elements of group Va to VIIa of the Periodic Table and may include vanadium oxides, manganese dioxide, manganese oxide, chromium trioxide, niobium pentoxide, tantalum pentoxide, molybdenum oxides or tungsten trioxide. Metal oxides with low lithium content are metal oxides as defined above which comprise a small amount of lithium, in which the molar ratio of lithium atoms to metal atoms is not more than 1:2.30.