Effect of Al2O3 -coating on the electrochemical performances of Li3V2(PO4)3/C cathode material

The effect of Al2O3 -coating on Li3V2(PO4)(3)/C cathode material for lithium-ion batteries has been investigated. The crystalline structure and morphology of the synthesized powders have been characterized by XRD, SEM, and HRTEM, and their electrochemical performances are evaluated by CV, EIS, and galvanostatic charge/discharge tests. It is found that Al2O3 -coating modification stabilizes the structure of the cathode material, decreases the polarization of electrode and suppresses the rise of the surface film resistance. Electrochemical tests indicate that cycling performance and rate capability of Al2O3-coated Li3V2(PO4)(3)/C are enhanced, especially at high rates. The Al2O3-coated material delivers discharge capacity of 123.03 mAh g(-1) at 4 C rate, and the capacity retention of 94.15 % is obtained after 5 cycles. The results indicate that Al2O3 -coating should be an effective way to improve the comprehensive properties of the cathode materials for lithium-ion batteries.