Electrochemical performance of Al2O3-coated Fe doped LiCOVO4

Al2O3-coated LiCo0.94Fe0.06VO4 powders with improved electrochemical cycleability have been synthesized. The morphology and structure of the coating have been characterized with SEM, HR-TEM and XPS. It was found that the Al2O3 coating was amorphous and that the particles were not completely coated, approximately 30-40% of the surface was covered. The Al2O3 coating had an average thickness of 10 nm. Cyclic voltammetry measurements versus Li/Li+ showed that the Al2O3-coated LiCo0.94Fe0.06VO4 sintered at 600degreesC showed the best capacity retention and the cycle tests revealed that the materials still possess a discharge capacity of 76 mA h g(-1) even after 80 cycles. The improved cycling performance is attributed to the ability of the Al2O3 layer to neutralize the HF component in the liquid electrolyte. (C) 2004 Elsevier B.V. All rights reserved.