A Novel Synthesis Route for LiFePO_4/C Cathode Materials for Lithium-Ion Batteries

摘要

A novel synthesis route for LiFePO_4 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 LiFePO_4/C composite precursor was prepared by a mechanical/chemical reaction of a stoichiometric mixture of metal iron powder, FePO_4 and Li_3PO_4 centre dot 1/2H_2O together with the proper amount of sucrose as conductive additive precursor. The resulting product was heat-treated at 600 deg C for 30 min to obtain the LiFePO_4/C cathode material. X-ray diffraction analysis indicated olivine type LiFePO_41C product with a pure orthorhombic phase indexed to the Pnmb space group. The LiFePO_41C material shows excellent cycle performance with a high capacity of 164 m Ah/g at the 0.1C discharge rate and 137 m Ah/g at the 1C discharge rate, respectively. No obviously capacity fade was observed after 60 cycles.