Physical and Electrochemical Properties of Lithium Iron Phosphate Synthesized by Gel-Solid State Reduction Method

Abstract

A lithium iron phosphate composite LiFePO4/C as cathode material for lithium ion battery was synthesized by sol-gel and high temperature solid state reduction method. The crystalline structure, morphology of particles and electrochemical performances of the sample were investigated by X-ray diffraction, scanning electron microscopy and charge-discharge test. Crystal structure and electrochemical performances of the composite relates to the heat treatment temperature. The composite synthesized under 700°C is simple pure olive-type phase structure with relative uniformly distribution of particle size. Also high charge-discharge capacity and efficiency, good cycle ability and high rate capability were observed in electrochemical tests for the composite. However, the capacity loss under high temperature, which may be the main content of further study.