Formation of tin oxide superstructures on reduced graphene oxide nanosheets for high-performance supercapacitor with excellent cyclic stability

Among a wide range of metal oxide semiconductors, tin dioxide (SnO 2 ) has been considered a promising material for pseudocapacitive electrodes. However, the performance of SnO 2 supercapacitor is severely limited owing to their low electrical conductivities. Herein, we proposed SnO 2 nanospheres (SnO 2 -NS) and reduced graphene oxide (rGO)-SnO 2 superstructures (SnO 2 -rGO SS ) for high performance supercapacitor. Cyclic voltammetry (CV) confirmed the capacitive behavior of the SnO 2 -rGO SS and SnO 2 -NS electrodes, with a specific capacitance of 320 and 44 F/g respectively, at a sweep rate of 5 mV/s. Remarkably, after cycling for 10,000 times at a sweep rate of 2 A/g, the SnO 2 -rGO SS electrode retained 150% more capacity than its initial value, indicating its outstanding durability.