Porous MnO2–CNTs–Cellophane Nanocomposite for High-Voltage Flexible Supercapacitors

Abstract

Flexible MnO2–CNTs–cellophane electrode was easily fabricated via addition of NaHCO3 in matrix of manganese dioxide-carbon nanotubes-cellophane composite followed by selective etching of NaHCO3 in acidic solution to produce a porous network structure as result of CO2 (g) bubbling. Under the optimized mass loading, the flexible-porous electrode presented favorite electrochemical capacitance behavior with the areal capacitance of 121 and 55.5 mF cm−2 at the current density of 0.6 mA cm−2 in 1.0 M H2SO4 and Na2SO4 electrolytes, respectively. A symmetric all-solid-state supercapacitor assembled with the flexible MnO2/CNTs/cellophane electrode showed a wide working voltage (2.0 V), a high areal capacitance of 82.5 mF cm−2 at a current density of 2.0 mA cm−2, favorite flexibility and good cycling stability (83% after 2000 cycles at a current density of 2.0 mA cm−2). Therefore, such a simple and scalable procedure to produce flexible supercapacitor device based MnO2–CNTs composite is offering for future flexible energy storage systems. Flexible solid-state supercapacitor device based on MnO2–CNTs–cellophane electrode.