Electrochemical properties of carbon-coated LiFePO4 synthesized by a modified mechanical activation process

Carbon-coated lithium iron phosphate (LiFePO4/C) composites were synthesized by conventional mechanical activation (MA) process and also by a modified MA process. Phase-pure particles were obtained of similar to 100nm size with a nano-meter thick web of carbon surrounding the particles. The composite prepared by the modified MA process shows good performance as cathode material in lithium cells at room temperature. A high performance was achieved at 0.1 C-rate with > 96% utilization of the active material. A stable cycle performance even at higher C-rates was achieved with a cathode that has a total carbon content of only 12wt%. The use of the modified MA process to synthesize LiFePO4/C has promise to be an efficient process to decrease the total carbon content of the cathode, resulting in the enhanced energy density. (C) 2008 Elsevier Ltd. All rights reserved.