Physical and electrochemical properties of La-doped lithium iron phosphate

La-doped lithium iron phosphates were synthesized via solid-state synthesis method, followed by sintering at high temperature for crystallization. The samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM). Their electrochemical properties were investigated by galvanostatic charge and discharge tests. The results indicate that rare earth lanthanum ion doping does not affect the structure of the material but considerably improves its capacity delivery and cycle performance, which is ascribed to the enhancement of the electronic inductivity and reducing crystal size to nanoscale by ion doping. The optimum cells with Li0.99La0.01FePO4 cathode show relatively high capacity of 123 mAh/g close to 73% of the theoretical capacity for C/20 discharge rate.