Polyaniline-wrapped metal oxide nanostructures/organic framework-derived heteroatom-doped carbon ternary composites for asymmetric supercapacitors: Constructing a 4.4 V cell

In this study, we synthesized polyaniline-wrapped metal oxide (MnO2or SnO2) nanostructures/covalent organic framework-derived N-doped carbon (NC) ternary composites for asymmetric supercapacitors. The ternary composites were characterized using a range of techniques. The polyaniline@MnO2/NC (PMNC) and polyaniline@SnO2/NC (PSNC) ternary composites delivered capacities of 410 and 534 C g−1, respectively, at 1.0 A g−1current density. The higher capacity of the electrodes is due to the double-layer capacitance from NC, pseudocapacitance from polyaniline, and redox reaction of metal oxides. The PMNC and PSNC ternary composites retained 98.3 % and 97.7 % of the starting capacity ensuing 5000 cycles at 10 and 5 A g−1, respectively. The asymmetric electrode achieved a specific energy of 36 Wh kg−1for PMNC and 41 Wh kg−1for PSNC. After charging the PSNC asymmetric supercapacitor device for 15 s at 4.4 V, a red light-emitting diode (1.6 V) was powered for over 10 min.