US Patent 7722848 Lithium iron phosphate cathode material

Lithium iron phosphate cathode materials for lithium secondary batteries and methods of preparation thereof are disclosed. Better cathode materials may be produced by multiple annealing and/or heating steps. The annealing step can be carried out before and/or after the heating steps to provide cathode materials, which exhibit superior electrical properties. In some instances, divalent iron compounds are incorporated as starting materials.