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 (SnO₂@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 SnO₂@C/GO composite jointly contribute to a good immobilization effect for the SnO₂ quantum dots. The hierarchical carbonaceous matrix supported SnO₂ 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 SnO₂@C/GO composite shows a high reversible capacity of 1156 mAh·g^-1 at the current density of 1000 mA·g^-1 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.