Enhanced capability and cyclability of SnO2–graphene oxide hybrid anode by firmly anchored SnO2quantum dots

Abstract

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.