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

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.