The capacitive behavior of MnO2 was rst reported in 1999
by Lee and Goodenough.20 They synthesized amorphous
hydrated MnO2 by reacting KMnO4 with Mn(CH3COO)2 and
found that MnO2-based composite electrodes showed an almost
ideal supercapacitive behavior. There are many other reports on
the electrochemical properties of MnO2 nanostructures. Yuan
et al.21 reported a novel and highly exible solid-state supercapacitor based on carbon nanoparticle/MnO2 nanorod hybrid
structures fabricated using a simple ame synthesis method