Enhanced electrochemical performance of lifepo₄/c composite cathode by a novel glycine-Assisted sol-gel synthesis

The carbon-coated LiFePO₄/C cathode active material was successfully synthesized via a glycine-Assisted sol-ge method. Glycine was used both as the chelating reagent and the carbon source. The effect of the carbon source o the structural, morphological and electrochemical properties of LiFePO₄ are studied in this paper. The structure morphology and electrochemical performance were investigated by X-ray diffraction (XRD), scanning electro microscopy (SEM), and galvanostatic charge-discharge test. The results indicated that glycine did not affect th crystal structure, but restrained the particle size of LiFePO₄/C. The SEM images revealed that the majority of th particles lay between 900 and 5000nm for pure LiFePO₄, while the carbon-coated LiFePO₄ particles were from 40 to 900 nm. The LiFePO₄/C sample synthesized at 700°C for 8 h delivered the highest initial discharge specifi capacity of 163.5 mAh/g, i.e. 96.2% of the theoretical capacity. It retained a high discharge capacity of 112.3mAh/ over 20 cycles at 1C rate. The glycine-Assisted sol-gel synthesis is favor to obtain the high electrochemica performance of LiFePO₄C.