Preparation and Performance of LiFePO4/C Composite Material via Reduction-Inserted Lithium in the Presence of Coating with Carbon

Abstract:

LiFePO4/C composite cathode material was prepared with polyacrylic acid as carbon source by a method combining a low temperature reduction-inserted lithium and polymer pyrolysis, in which FePO4 was reduced with lithium insertion and a simultaneous chemical coating occurred with carbon-containing polymer. The technique simplifies the preparation process and reduces the production cost. The phase structures, lattice parameters, morphologies and electrochemical properties of LiFePO4/C samples synthesized at different calcination temperatures were characterized by XRD, SEM and galvanostatic charge-discharge test. The results show that the maximum discharge capacity and best cycling stability of present products are obtained when the calcination temperature is 600 oC at 0.1C rate. The initial discharge specific capacities of resulting LiFePO4/C composite material reaches 141.3 mAh/g with a coulombic efficiency of 98.0% at 0.1C rate, and the capacity retention rate is 108.3% after 100 cycles.