A modified mechanical activation synthesis for carbon-coated LiFePO4 cathode in lithium batteries

Abstract

An efficient synthesis based on mechanical activation (MA) was developed for carbon-coated lithium iron phosphate (LiFePO4/C). The conventional MA process was modified by introducing two initial steps of slurry phase blending of the ingredients and solvent removal by rotary evaporation, so as to get an intimate mixing and homogenous dispersion of conductive carbon in the sample. Phase-pure, nanometer-sized particles of the active material covered with a porous, nanometer-sized web of carbon were obtained. LiFePO4/C exhibited remarkably good electrochemical properties when evaluated as cathodes in room temperature lithium cells. An initial discharge capacity of 166 mAh/g (corresponding to 97.6% of theoretical capacity) was achieved at 0.1 C-rate. A very stable cycle performance was also realized, good capacity retention up to 100 cycles was achieved at different current densities. (c) 2006 Elsevier B.V. All rights reserved.