In situ preparation of FeFx•yH2O/C composite as cathode material for Li batteries

Abstract

FeF[Formula: see text]H2O/C composite is prepared by using ferric citrate (FeC6H5O[Formula: see text] as precursor via carbonization and fluoridation. When evaluated as cathode materials for lithium batteries, the as-prepared FeF[Formula: see text]H2O/C composite can retain a capacity of 116[Formula: see text]mAh[Formula: see text]g[Formula: see text] at 40[Formula: see text]mA[Formula: see text]g[Formula: see text] after 300 cycles in the voltage range of 2.0–4.5 V. The cycling performance should be attributed to Fe2F[Formula: see text]H2O as a main component and carbon decoration. The electrical conductivity of Fe2F[Formula: see text]H2O is higher than other iron fluorides, and it also possesses an open framework in its crystal structure for facilitating the transport of Li[Formula: see text]. The simple preparation, unique crystal structure and superior electrochemical performance of FeF[Formula: see text]H2O/C composite show its great potential of being an alternative cathode material for lithium batteries.