Construction of SnO₂-Graphene Composite with Half-Supported Cluster Structure as Anode toward Superior Lithium...

Inspired by nature, herein we designed a novel construction of SnO₂ anodes with an extremely high lithium storage performance. By utilizing small sheets of graphene oxide, the partitioned-pomegranate-like structure was constructed (SnO₂@C@half-rGO), in which the porous clusters of SnO₂ nanoparticles are partially supported by reduced graphene oxide sheets while the rest part is exposed (half-supported), like partitioned pomegranates. When served as anode for lithium-ion batteries, SnO₂@C@half-rGO exhibited considerably high specific capacity (1034.5 mAh g^-1 after 200 cycles at 100 mA g^-1), superior rate performance and remarkable durability (370.3 mAh g^-1 after 10000 cycles at 5 A g^-1). When coupled with graphitized porous carbon cathode for lithium-ion hybrid capacitors, the fabricated devices delivered a high energy density of 257 Wh kg^-1 at ∼200 W kg^-1 and maintained 79 Wh kg^-1 at a super-high power density of ∼20 kW kg^-1 within a wide voltage window up to 4 V. This facile and scalable approach demonstrates a new architecture for graphene-based composite for practical use in energy storage with high performance.