Synthesis of LiFePO4/C composite electrode with enhanced electrochemical performance

LiFePO4/C composite was synthesized by high temperature solid-state reaction using iron( Ⅱ ) oxalate,ammonium di-hydrogen phosphate and lithium carbonate with a kind of carbohydrate dissolved in the dispersant(ethanol) as carbon sources added to the synthetic precursor. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy observations(SEM), charge/discharge test, cyclic voltammetry(CV) and carbon analysis. The results show that the synthesis of LiFePO4/C has ordered olivine structure. The carbon has two advantages: optimizing particle size of LiFePO4 and increasing the electronic conductivity and high Li+ diffusivity.The cathode material can demonstrate a charge/discharge flat voltage of 3.4 V(vs Li+/Li). Especially the active material with 15 % and 20% carbohydrate added according to the final product of lithium iron phosphate shows very respectively at 0. 1 C rate and the carbon contents in the final production are only 5.17% and 5.29%, respectively.