Electrochemical properties of LiAlxFe1−3x/2PO4/C prepared by a solution method

Olivine compounds LiAlxFe1−3x/2PO4/C [x=0x=0, 0.01, 0.02, 0.04, 0.06, 0.12] were prepared via an easy solution method and electrochemical properties were examined by means of X-ray diffraction, cyclic voltammetry, and charge–discharge tests. The results indicate that Al3+ does not affect the olivine structure of the cathode but considerably improves its initial capacity and cycle performance. Among the Al3+-substitution powders, LiAl0.01Fe0.985PO4/C shows the best electrochemical performance. It shows initial specific discharge capacities of 157.67 and 126.65 mA hg−1 with C rates of 0.5 C and 5 C, respectively, which is ascribed to the enhancement of the electronic conductivity by Al3+-substitution and carbon coating.