Effect of CeO2-coating on the electrochemical performances of LiFePO4/C cathode material

The effect of CeO2 coating on LiFePO4/C cathode material has been investigated. The crystalline structure and morphology of the synthesized powders have been characterized by XRD, SEM, TEM and their electrochemical performances both at room temperature and low temperature are evaluated by CV, EIS and galvanostatic charge/discharge tests. It is found that, nano-CeO2 particles distribute on the surface of LiFePO4 without destroying the crystal structure of the bulk material. The CeO2-coated LiFePO4/C cathode material shows improved lithium insertion/extraction capacity and electrode kinetics, especially at high rates and low temperature. At −20 °C, the CeO2-coated material delivers discharge capacity of 99.7 mAh/g at 0.1C rate and the capacity retention of 98.6% is obtained after 30 cycles at various charge/discharge rates. The results indicate that the surface treatment should be an effective way to improve the comprehensive properties of the cathode materials for lithium ion batteries.

► The first study the effect of CeO2 coating on LiFePO4/C at low temperature. ► Coated cathode shows improved capacities at high rates and low temperature. ► CeO2-coating decreases electrode polarization and increases charge-transfer reaction activity.