METHOD FOR PREPARING CRYSTALLINE IRON PHOSPHATES DOPED WITH METAL

Provided are a crystalline iron phosphate doped with metals (MFePO 4 ), which is used as a precursor of olivine-structured LiMFePO 4 (LMFP) used as a cathode active material for lithium secondary batteries, and a method of preparing the crystalline iron phosphate, in which a crystalline iron phosphate doped with metals has the following Formula I obtained by crystallizing amorphous iron phosphate and doping the latter with a different type of a metal. Formula I: MFePO 4 , where M is selected from the group consisting of Ni, Co, Mn, Cr, Zr, Nb, Cu, V, Ti, Zn, Al, Ga, Mg, and B. The preparation of olivine-structured LMFP, which is used as a cathode active material for lithium secondary batteries, using the crystalline iron phosphate doped with metals as a precursor can increase efficiency and reduce processing costs as compared to another method of preparing the same by mixing different types of metals in a solid state.