Enhanced electrochemical properties of Al2O3-coated LiV3O8 cathode materials for high-power lithium-ion batteries

Surface modified-LiV3O8 cathode materials with Al2O3 are successfully synthesized via a facile thermolysis process. The 0.5 wt.% Al2O3-coated LiV3O8 exhibits an enhanced cyclic stability at various charge-discharge current densities. At a current density of 100 mA g(-1), it delivers an initial specific discharge capacity of 283.1 mAh g(-1) between 2.0 and 4.0 V. Moreover, high capacities of 139.4 and 118.5 mAh g(-1) are obtained at the 100th cycle at current densities of 2000 and 3000 mA g(-1), respectively. The improved electrochemical performance is attributed to the Al2O3 coating, which can hinder the irreversible phase transformation and act as a protective layer to prevent the active material from direct contact with electrolyte. Furthermore, the formation of a Li-V-Al-O solid solution at the LiV3O8/Al2O3 interface provides a fast Li+ diffusion path which is of benefit to the electrochemical behaviors. (C) 2013 Elsevier B.V. All rights reserved.