The Preparation of LiFePO[sub 4]∕C Cathode by a Modified Carbon-Coated Method

Abstract

A method to prepare lithium iron phosphate (LiFePO4) was desert bed, in which the raw materials were coated with carbon source gel to obtain a carbon-coated precursor. The precursor wits first heated at 400 degrees C for 10 h, and then calcined at 730 degrees C for 20 h to get a black LiFePO4/C powder. To compare with previously reported carbon source feeding way it carbon-coated LiFePO4/C sample wits synthesized in conventional way. X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and elemental analyzer were employed to analyze the crystal structure, surface element distribution, and shape of precursors and LiFePO4/C samples. In addition, the electrochemical performance of the LiFePO4/C Was tested by charge-discharge cycling test. It wits concluded that coating carbon source gel oil the precursor before heating process makes the coated carbon homogeneously distributed on the grain surface of the LiFePO4. This leads the LiFePO4 sample to have a better electrochemical performance than the sample made by other methods. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3184342] All rights reserved.