Engineering tin dioxide quantum dots in a hierarchical graphite and graphene oxide framework for lithium-ion storage.

The spontaneous aggregation and poor electronic conductivity are widely recognized as the main challenges for practically applied nano-sized tin dioxide-based anode candidates in lithium-ion batteries. This work describes a hierarchical graphite and graphene oxide (GO) framework stabilized tin dioxide quantum dot composite (SnO@C/GO), which is synthesized by a solid-state ball-milling treatment and a water-phase self-assembly process. Characterization results demonstrate the engineered inside nanostructured graphite and outside GO layers from the SnO@C/GO composite jointly contribute to a good immobilization effect for the SnO quantum dots. The hierarchical carbonaceous matrix supported SnO quantum dots could maintain good structure stability over a long cycling life under high current densities. As an anodic electrochemically active material for lithium-ion batteries, the SnO@C/GO composite shows a high reversible capacity of 1156 mAh·g at the current density of 1000 mA·g for 350 continual cycles as well as good rate performance. The large pseudocapacitive behavior in this electrode is favorable for promoting the lithium-ion storage capability under higher current densities. The whole synthetic route is simple and effective, which probably has good potential for further development to massively fabricate high-performance electrode active materials for energy storage.