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

Benefiting from the reversible conversion reaction upon delithiation, nanosized SnO, with its theoretical capacity of 1494 mA h g, has gained special attention as a promising anode material. Here, we report a self-assembled SnO/Sn-reduced graphene oxide (rGO) sandwich nanocomposite developed by organometallic precursor coating and in situ transformation. Ultrafine SnO 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 nanoparticles but also facilitates the charge transfer and reaction kinetics of SnO upon lithiation/delithiation. As a result, the SnO/Sn-rGO nanocomposite exhibited a superior lithium storage capacity with a reversible capacity of 1307 mA h g at a current density of 80 mA g in the potential window of 0.01-2.5 V versus Li/Li and showed a reversible capacity of 767 mA h g over 200 cycles at a current density of 400 mA g. When cycling at a higher current density of 1600 mA g, the SnO/Sn-rGO nanocomposite showed a highly stable capacity of 449 mA g without obvious decay after 400 cycles.