In Situ Preparation of FeFx•yH2O/C Composite As Cathode Material for Li Batteries

FeFx center dot yH(2)O/C composite is prepared by using ferric citrate (FeC6H5O7) as precursor via carbonization and fluoridation. When evaluated as cathode materials for lithium batteries, the as-prepared FeFx center dot yH(2)O/C composite can retain a capacity of 116 mAh g(-1) at 40 mA g(-1) after 300 cycles in the voltage range of 2.0-4.5 V. The cycling performance should be attributed to Fe2F5 center dot 2H(2)O as a main component and carbon decoration. The electrical conductivity of Fe2F5 center dot 2H(2)O is higher than other iron fluorides, and it also possesses an open framework in its crystal structure for facilitating the transport of Li+. The simple preparation, unique crystal structure and superior electrochemical performance of FeFx center dot yH(2)O/C composite show its great potential of being an alternative cathode material for lithium batteries.