Highly Efficient High-Pressure Homogenization Approach for Scalable Production of High-Quality Graphene Sheets and Sandwich-Structured α-FeO/Graphene Hybrids for High-Performance Lithium-Ion Batteries.

A highly efficient and continuous high-pressure homogenization (HPH) approach is developed for scalable production of graphene sheets and sandwich-structured α-FeO/graphene hybrids by liquid-phase exfoliation of stage-1 FeCl-based graphite intercalation compounds (GICs). The enlarged interlayer spacing of FeCl-GICs facilitates their efficient exfoliation to produce high-quality graphene sheets. Moreover, sandwich-structured α-FeO/few-layer graphene (FLG) hybrids are readily fabricated by thermally annealing the FeCl intercalated FLG sheets. As an anode material of Li-ion battery, α-FeO/FLG hybrid shows a satisfactory long-term cycling performance with an excellent specific capacity of 1100.5 mA h g after 350 cycles at 200 mA g. A high reversible capacity of 658.5 mA h g is achieved after 200 cycles at 1 A g and maintained without notable decay. The satisfactory cycling stability and the outstanding capability of α-FeO/FLG hybrid are attributed to its unique sandwiched structure consisting of highly conducting FLG sheets and covalently anchored α-FeO particles. Therefore, the highly efficient and scalable preparation of high-quality graphene sheets along with the excellent electrochemical properties of α-FeO/FLG hybrids makes the HPH approach promising for producing high-performance graphene-based energy storage materials.