Olivine LiFePO4/ C cathode materials were successfully prepared by solid state reaction with different carbon source( sucrose,citric acid and tartaric acid),and the effect of carbon source on the structure and the electrochemical performances were systematically investigated by XRD,TGA,SEM,Raman,charge-discharge test,cyclic voltammetry( CV),and AC impedance. Analysis from XRD results show that all-prepared powers can be indexed to be a single-phase of an orthorhombic olivine-type structure. Thermogravimetri...