A method for carrying out solid state reactions under reducing conditions is provided. Solid state reactants include at least one inorganic metal compound and a source of reducing carbon. The reaction may be carried out in a reducing atmosphere in the presence of reducing carbon. Reducing carbon may be supplied by elemental carbon, by an organic material, or by mixtures. The organic material is one that can form decomposition products containing carbon in a form capable of acting as a reductant. The reaction proceeds without significant covalent incorporation of organic material into the reaction product. In a preferred embodiment, the solid state reactants also include an alkali metal compound. The products of the method find use in lithium ion batteries as cathode active materials. Preferred active materials include lithium-transition metal phosphates and lithium-transition metal oxides. In a preferred embodiment, the reaction product contains carbon particles intimately mixed among crystals of the active materials.