A facile synthesis and characterization of LiFePO_4/C using simple binary reactants with oxalic acid by polyol technique and other high temperature methods

摘要

An attempt has been made to synthesize the carbon coated Fe-based phospho-olivine nano-crystalline cathode materials using simple binary sources via polyol method. Also, a curious attempt has been made to compare the material with the high temperature methods, viz., hydrothermal and solid state method with the same binary sources as raw materials and oxalic acid as a carbon source. The thermal behaviour of the mixed raw materials of LiFePO_4 and thermal stability of the final prepared materials were characterized by TGA. The prepared materials were confirmed as orthorhombic olivine structure with Pnma space group. LiFePO_4/C material prepared by Polyol method exhibits an initial reverse capacity of 150 mAh g~(-1) at 0.1 C rate under room temperature. Also, stable capacity of 143 mAh g~(-1) has been observed over 50 cycles at 0.1 C rate at room temperature among the other methods studied. It may be due to the coverage of tiny particles by carbon and it leads to provide better electronic conductivity and thereby provides good electrochemical performances.