Scalable synthesis of ultrasmall SnO2 nanocrystals in carbon conductive matrices: High loading and excellent electrochemical performance

Abstract Ultrasmall sub-5 nm SnO 2 nanocrystals/carbon composites, with the SnO 2 loading as high as 87.3 wt%, are synthesized via a facile hydrothermal route, followed by calcination. The annealed SnO 2 /C composite shows a higher discharge capacity and superior rate performance, compared with the pristine SnO 2 /C sample. At the current density of 200 mA g −1 , it can deliver a high reversible capacity of 968 mAh g −1 . When the current density increases to 5000 mA g −1 , a high discharge capacity of 435 mAh g −1 can still be obtained, much higher than the theoretical capacity of graphite. Our results indicate the potential suitability of synthesizing ultrasmall electrode nanocrystals with high electrochemical performance.