A Novel Synthesis Route for LiFePO[sub 4]/C Cathode Materials for Lithium-Ion Batteries

A novel synthesis route for 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 composite precursor was prepared by a mechanical/chemical reaction of a stoichiometric mixture of metal iron powder, and together with the proper amount of sucrose as conductive additive precursor. The resulting product was heat-treated at 600°C for 30 min to obtain the cathode material. X-ray diffraction analysis indicated olivine type product with a pure orthorhombic phase indexed to the Pnmb space group. The 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.