Facile synthesis of high-performance LiFePO4-reduced graphene oxide composites using ball milling

Abstract

We developed a simple, green, and solvent-free method for the synthesis of LiFePO4-reduced graphene oxide (LFP-RGO) composites with enhanced electrochemical performance. RGO sheets (synthesized using supercritical ethanol) and LFP precursors (produced using a co-precipitation method) were uniformly mixed by ball milling. The micron-sized co-precipitated LFP precursors were partially pulverized, and the RGO sheets were uniformly distributed in the LFP precursors during the ball milling process. After subsequent calcination of the LFP precursor-RGO mixture, a uniform coverage of RGO sheets with thickness of approximately 10 nm was observed on the surface of the LFP particles. The LFP-RGO composite exhibited a high reversible capacity of 158 mAh g−1 at 0.1 C, an excellent rate performance of 92 mAh g−1 at 10 C, and an extremely small decay rate of 0.021 mAh g−1 per cycle over 1000 cycles at 1 C. The effects of the RGO content and ball milling speed on the physicochemical and electrochemical properties of the LFP-RGO composites were discussed.