Hierarchical nanostructures of polypyrrole@MnO2 composite electrodes for high performance solid-state asymmetric supercapacitors

Abstract

A solid-state high performance flexible asymmetric supercapacitor (ASC) was fabricated. Its anode is based on organic–inorganic materials, where polypyrrole (PPy) is uniformly wrapped on MnO₂ nanoflowers grown on carbon cloth (CC), and its cathode is made of activated carbon (AC) on CC. The ASC has an areal capacitance of 1.41 F cm⁻² and an energy density of 0.63 mW h cm⁻² at a power density of 0.9 mW cm⁻². An energy storage unit fabricated using multiple ASCs can drive a light-emitting diode (LED) segment display, a mini motor and even a toy car after full charging. The high-performance ASCs have significant potential applications in flexible electronics and electrical vehicles.