Electrochemical properties of LiFePO4 prepared via ball-milling

LiFePO4 cathode materials with distinct particle sizes were prepared by a planetary ball-milling method. The effects of particle size on the morphology, thermal stability and electrochemical performance of LiFePO4 cathode materials were investigated. The ball-milling method decreased particle size, thereby reducing the length of diffusion and improving the reversibility of the lithium ion intercalation/deintercalation. It is worth noting that the small particle sample prepared using malonic acid as a carbon source achieved a high capacity of 161 mAh g(-1) at a 0.1 C rate and had a very flat capacity curve during the early 50 cycles. However, the big particle samples (similar to 400 nm) decayed more dramatically in capacity than the small particle size samples (similar to 200nm) at high current densities. The improvement in electrode performance was mainly due to the fine particles. the small size distribution, and the increase in electronic conductivity as a result of carbon coating. The structure and morphology of the ground LiFePO4 samples were characterized with XRD, FE-SEM, TEM, EDS, and DSC techniques. (C) 2008 Elsevier B.V. All rights reserved.