Journal of Power Sources, Vol.246, 232-238, 2014
A novel synthesis and characterization of LiFePO4 and LiFePO4/C as a cathode material for lithium-ion battery
A novel hydrothermal stripping technique is developed to synthesize pure LiFePO4 and LiFePO4/C cathode materials. The pure sample is directly synthesized by the cation exchange between the organic phase which is prepared with FeSO4 center dot 7H(2)O and naphthenic acid, and aqueous phase prepared with H3PO4 and LiOH. SEM exhibits that the primary sizes of the well-distributed LiFePO4 and LiFePO4/C particles are about 150 nm and 100 nm in diameter, respectively. TEM indicates the LiFePO4/C is uniformly coated with a carbon layer about 2.7 nm in size. The as-prepared LiFePO4 exhibits a high initial discharge capacity of 135.5 mAh g(-1) at 0.1 C, and the LiFePO4/C composite sintered at 650 degrees C for 4 h exhibits the best electrode properties with discharge capacities of 151.7, 154.8, 149.8 and 139.1 mAh g(-1) at 0.1 C, 0.2 C, 0.5 C and 1.0 C rates, respectively. In addition, the LiFePO4/C also shows excellent capacity retention and cycle performances. (C) 2013 Elsevier B.V. All rights reserved.
Keywords:Cathode materials;Lithium iron phosphate;Lithium iron phosphate/Carbon;Hydrothermal stripping method;Electrochemical performance