Binary metal oxide (MnO2/SnO2) nanostructures supported triazine framework-derived nitrogen-doped carbon composite for symmetric supercapacitor

A high-performance supercapacitor was fabricated using binary metal oxide (manganese oxide and tin oxide) decorated triazine framework-derived nitrogen-doped carbon (MnO2@SnO2/T-NC) composites. Morphological analysis showed that the SnO2/T-NC composite surface was densely decorated with MnO2 nanorods (<20 nm). The MnO2@SnO2/T-NC (5:1) composite delivered a capacitance of 676 F g(-1) at 1 A g(-1) current density. The symmetric system displayed a capacitance of 91.1 F g(-1) at 1 A g(-1) with good cycling stability. After 7000 cycles, the device withheld 92.3 % of its total capacitance at 3 A g(-1). The electrode's high performance may be ascribed to the redox reaction of metal oxides and fast electrolyte transport through porous carbon. After charging the symmetric supercapacitor device for 23 s at 4.4 V, green (2.0 V) and blue (3.3 V) light-emitting diodes were powered for 21 and 10 min, respectively.