Enhanced capability and cyclability of SnO2-graphene oxide hybrid anode by firmly anchored SnO2 quantum dots

A SnO2-graphene oxide (GO) hybrid composite was prepared by binding SnO2 nanocrystals smaller than 5 nm in GO using a facile hydrothermal method. Aided by hydrophilic radicals, such as hydroxyl and carboxyl, in in situ forming SnO2 quantum dots, the active material and the flexible support are highly coupled. When used as an anode material for lithium ion batteries (LIBs), the hybrid composite electrode delivers a high reversible capacity of nearly 800 mA h g(-1) (based on the total weight of the composite, discharging at 100 mA g(-1)) with more than 90% retention for 200 cycles. Besides the excellent cycling performance at various rates, the composite also exhibits a superior rate performance at 10 A g(-1) with recoverable initial reversible capacity and a long lifespan of 1000 cycles with 80% capacity retention, outperforming most previous SnO2-graphene hybrid electrodes.