Synthesis of cage-like LiFePO4/C microspheres for high performance lithium ion batteries

Cage-like LiFePO4 microspheres are synthesized by a solvothermal reaction-calcination process, using Fe(NO3)(3)center dot 9H(2)O as iron source and ethylene glycol/water as co-solvent medium. The microsphere is the assembly of LiFePO4 nanoparticles with an open porous structure, thus the carbon coating can be easily introduced on the surface of the nanoparticles by the chemical vapor deposition of C2H4 during calcination process. When used as the cathode materials for the lithium-ion batteries, the resultant cage-like LiFePO4/C microsphere shows high capacity and good cycle stability (160 mAh g(-1) at 0.1 C over 300 cycles), as well as good rate capability (120 mAh g(-1) at 10 C). The desirable electrochemical performance can be attributed to high rate of ionic/electronic conduction and the high structural stability arising from the interconnected open pores, carbon-coated nanoparticles and microsized structure. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.