Novel synthesis route for LiFePO4/C cathode materials for lithium-ion batteries

A novel synthesis route for LiFePO4 cathode materials was developed based on a ballmilling technique. In the new synthesis route metallic iron powder and iron(III) phosphate were used as the iron source instead of iron(II). A LiFePO4/C composite precursor was prepared by a mechanical/chemical reaction of a stoichiometric mixture of metal iron powder, FePO4 and Li3PO4 center dot 1/2H(2)O together with the proper amount of sucrose as conductive additive precursor. The resulting product was heat-treated at 600 degrees C for 30 min to obtain the LiFePO4/C cathode material. X-ray diffraction analysis indicated olivine type LiFePO4/C product with a pure orthorhombic phase indexed to the Pnmb space group. The LiFePO4/C material shows excellent cycle performance with a high capacity of 164 mAh/g at the 0.1C discharge rate and 137 mAh/g at the 1C discharge rate, respectively. No obviously capacity fade was observed after 60 cycles. (C) 2004 The Electrochemical Society.