Synthesis and characterization of LiFe0.9Mg0.1PO4/nano-carbon webs composite cathode

LiFe0.9Mg0.1PO4/nano-carbon webs composite cathode material was synthesized from nanocrystalline Fe3O4 through sol-gel process, followed by carbothermal reduction reaction in the presence of LiOH center dot H2O and NH4H2PO4. Sucrose molecule was introduced through liquid phase and used to construct carbon webs structure. FE-SEM and HR-TEM observations show that decomposed carbon can form typical carbon webs structure to connect and wrap LiFe0.9Mg0.1PO4 particles. Electrochemical tests indicated that the Mg-doping at 4c site of carbon-coated LiFePO4 did not affect the olivine structure of the lithium iron phosphate but obviously improve its discharge capacity and rate capability, which would be ascribed to the increased electronic conductivity and/or the mobility of Li+ ion induced by the doping method. (C) 2008 Elsevier B.V. All rights reserved.