Organometallic Precursor-Derived SnO₂/Sn-Reduced Graphene Oxide Sandwiched Nanocomposite Anode with Superior Lithium Storage Capacity

Benefiting from the reversible conversion reaction upon delithiation, nanosized SnO 2, with its theoretical capacity of 1494 mA h g –1, has gained special attention as a promising anode material. Here, we report a self-assembled SnO 2 /Sn-reduced graphene oxide (rGO) sandwich nanocomposite developed by organometallic precursor coating and in situ transformation. Ultrafine SnO 2 nanoparticles with an average diameter of 5 nm are sandwiched within the rGO/carbonaceous network, which not only greatly alleviates the volume changes upon lithiation and aggregation of SnO 2 nanoparticles but also facilitates the charge transfer and reaction kinetics of SnO 2 upon lithiation/delithiation. As a result, the SnO 2 /Sn-rGO nanocomposite exhibited a superior lithium storage capacity with a reversible capacity of 1307 mA h g –1 at a current density of 80 mA g –1 in the potential window of 0.01–2.5 V versus Li + /Li and showed a reversible capacity of 767 mA h g –1 over 200 cycles at a current density of 400 mA g –1 . When cycling at a higher current density of 1600 mA g –1, the SnO 2 /Sn-rGO nanocomposite showed a highly stable capacity of 449 mA g –1 without obvious decay after 400 cycles.