Nonaqueous sol-gel synthesis of high-performance LiFePO4

Abstract

A simple, versatile nonaqueous sol-gel method for the synthesis of carbon-coated LiFePO4 as high-performance cathode is reported. The method consists of two simple steps: (i) dissolve lithium acetate, iron(II) acetate and phosphoric acid in ethylene glycol to form a molecularly homogeneous, monolithic organo-gel and (ii) directly heat the gel in nitrogen atmosphere to form carbon-coated, phase-pure LiFePO4. The LiFePO 4 formed consists of 200-300 nm particles with rather uniform size distribution and with 1-4 wt % surface carbon coating formed in situ. The favorable physical characteristics of the synthesized LiFePO4 give rise to excellent rate performance. © 2004 The Electrochemical Society. All rights reserved.