Confinement of nanosized tin(IV) oxide particles on rGO sheets and its application to sodium-ion full cells as a high capacity anode material

In this study, we report the synthesis and electrochemical reactions of nanosized SnO2/reduced graphene oxide (rGO), as well as its cell performance that implement full cells coupled with carbon-coated NaCrO2 cathodes. We synthesize nanosized SnO2/rGO composites to mitigate main drawback that conversion and alloy reaction materials suffer from self-pulverization on discharge (reduction). Hydrothermally produced SnO2 nanoparticles are simultaneously attached onto rGO sheets via a self-assembly process, in which rGO sheets provide sufficient electron conduction paths (∼10−3 S cm−1) during electrochemical reactions. As anticipated, this technique results in satisfactory cell performance with help from the effect mentioned above. For the first time, we apply the SnO2/rGO composite materials to a full cell, adopting a carbon-coated NaCrO2 (110 mAh (g-NaCrO2)−1 cathode. The full cell demonstrates an excellent capacity retention, approximately 84% of the initial capacity (88 mAh (g-NaCrO2)−1) for 300 cycles, and is active even at a rate of 10C (1.05 A g−1), delivering 87 mAh (g-NaCrO2)−1. This result demonstrates the feasibility of using carbon-coated NaCrO2//SnO2/rGO sodium-ion cells for energy storage.