Electrochemical Charge/Discharge Cycling and Morphological Effects in Mno2/Panc Nanostructures for Supercapacitors

The improvement of electrochemical properties of MnO2 has been an attractive topic for a long time. Here, MnO2/polyacrylonitrile carbon (MnO2/PANC) nanostructures with well-modified morphology are required by chemical direct synthesis. The cycling stability and specific capacitance performance of MnO2/PANC electrode are enhanced during electrochemical cycling and explored to be closely related to the internal morphologies and crystal form of the various MnO2/PANC nanostructures. The Na+ ion and PANC are forced to interact with increased active sites of the MnO2/PANC surface by cycling protocol. The resulting electrode exhibits the defective nanostructure, in which the MnOC bond is introduced and comprehensive Mn valence occurred in the untrathin MnO2/PANC nanostructure; such unique core-shell nanostructure, providing more structural defects, increased surface area and rich functional groups, and subsequently, enhanced electrochemical capacitance performance. Therefore, this work suggests a new concept for the development of manganese-based electrode materials with enhanced performance and may have broad application in high-energy storage devices.