Electrochemical charge/discharge cycling and morphological effects in MnO2/PANC nanostructures for supercapacitors

The improvement of electrochemical properties of MnO 2 has been an attractive topic for a long time. Here, MnO 2 /polyacrylonitrile carbon (MnO 2 /PANC) nanostructures with well-modified morphology are required by chemical direct synthesis. The cycling stability and specific capacitance performance of MnO 2 /PANC electrode are enhanced during electrochemical cycling and explored to be closely related to the internal morphologies and crystal form of the various MnO 2 /PANC nanostructures. The Na + ion and PANC are forced to interact with increased active sites of the MnO 2 /PANC surface by cycling protocol. The resulting electrode exhibits the defective nanostructure , in which the Mn O C bond is introduced and comprehensive Mn valence occurred in the untrathin MnO 2 /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.