Nonaqueous Sol-Gel Synthesis of High-Performance LiFePO_4

摘要

A simple, versatile nonaqueous sol-gel method for the synthesis of carbon-coated LiFePO_4 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 LiFePO_4. The LiFePO_4 formed consists of 200-300 nm particles with rather uniform size distribution and with 1-4 wt percent surface carbon coating formed in situ. The favorable physical characteristics of the synthesized LiFePO_4 give rise to excellent rate performance.