Large-scale fabrication of graphene-wrapped FeF sub(3) nanocrystals as cathode materials for lithium ion batteries

Graphene-wrapped FeF sub(3) nanocrystals (FeF sub(3)/G) have been successfully fabricated for the first time by a vapour-solid method, which can be generalized to synthesize other metal fluorides. The as-synthesized FeF sub(3)/G delivers a charge capacity of 155, 113, and 73 mA h g super(-1) at 104, 502, and 1040 mA g super(-1) in turn, displaying superior rate capability to bare FeF sub(3). Moreover, it exhibits stable cyclability over 100 cycles with a charge capacity of 185.6 and 119.8 mA h g super(-1) at 20.8 and 208 mA g super(-1), respectively, which could be ascribed to the buffering effect and lowered resistance from the graphene. This versatile vapour-solid method and the improved cyclability provide a promising avenue for the application of metal fluorides as cathode materials.