Structure-dependent lithium storage characteristics of Fe3O4/rGO aerogels

Reduced graphene oxide (rGO) not only shows distinctive electrochemical properties desirable for battery performance but also presents functionalities that enable the production of free-standing electrodes and allow further functionalization to form composites. When combined with Fe3O4 which possesses a high theoretical capacity, Fe3O4/rGO composites demonstrate enhanced battery performance compared to their individual form. Despite numerous efforts invested in developing high-performance Fe3O4/rGO Li-ion battery anodes, fundamental questions regarding structure-dependent lithium storage behaviour have been lacking experimental support in detail. In this work, we report the synthesis of free-standing Fe3O4/rGO that is highly porous with tunable features to increase the availability of electroactive sites, channels for ion passage, and space for Li accommodation, thus enhancing Li storage capacity and prolonging cycle life. As-prepared Fe3O4/rGO electrodes deliver a high reversible capacity of 1224 mAh g-1 at 100 mA g-1 and a retention rate of 82.8% after 1000 cycles at 1 A g-1. These Fe3O4/rGO composites with desirable features, hence, hold promise in applications as anodes in high-power lithium-ion batteries.