Optimization of SnO 2 Nanoparticles Confined in a Carbon Matrix towards Applications as High‐Capacity Anodes in Sodium‐Ion Batteries

SnO 2 /carbon composites including amorphous carbon and graphene or carbon nanotubes are synthesized by a gas‐liquid interfacial approach and subsequent annealing process. The effect of the carbon source and the conductive additive on the electrochemical performance is investigated by galvanostatic charge‐discharge tests. SnO 2 @Glucose/Graphene (SnO 2 @Glu/G) composites as anodes of sodium‐ion batteries show the best electrochemical performance, delivering 306 mA h g −1 after 100 cycles at 0.1 A g −1 between 0.01‐3 V, while exhibiting 278 and 226 mA h g −1 at 1 and 2 A g −1 , respectively. The mechanism of improved electrochemical performance for graphene is researched in detail. The results reveal a porous structure with fine SnO 2 particles due to the introduction of graphene oxide, and an effective electron charge transfer network from the graphene increases its reversible capacity, rate performance and cycling performance.