Enhanced electrochemical properties of LiMn1-xFexPO4/C composite cathode materials prepared by sol-gel method

摘要

Olivine-type LiMn1-xFexPO4/C(x= 0, 0.1, 0.3 and 0.5) composite materials were synthesized by the sol-gel method employing N,N-dimethylformamide (DMF) as a dispersing agent, and the structure and morphology of the as-prepared nanoparticles were characterized. For Fe2+ doping contents of x=0, 0.1, 0.3, and 0.5, initial specific discharge capacities of 96.8, 137.6, 152.3, and 161.5 mA h g(-1) at 0.05 C were obtained, respectively. The LiMn0.5Fe0.5PO4/C composite in particular exhibited an excellent reversible capacity of 132 mA h g(-1) at a charge-discharge rate of 1 C. Finally, LiMn0.5Fe0.5PO4/C retained 155.5 mA h g(-1) (96.3%) of the initial specific discharge capacity after 50 cycles, demonstrating excellent cyclability. (C) 2015 Elsevier B.V. All rights reserved.