Study on Degradation and Failure in Lithographically Patterned Gold/Manganese Dioxide Core/Shell Nanowires Based Supercapacitors

Nanostructured manganese oxide (MnO2) is one of the widely studied materials for electrochemical capacitors because of the high specific surface area and excellent electrochemical properties leading to improved rate capability and enhanced energy/power densities. Most of the research on MnO2 is aimed at improving the capacitance whereas only a few studies are focused on cycling stability of these electrodes. In this work, degradation in capacitance of arrays of gold core nanowire encapsulated within a hemicylindrical shell of MnO2 will be studied. The horizontal nanowire systems provide an excellent platform for analyzing nanowire performance, such as investigations of the mechanisms contributing to degradation and failure in these systems. Ex-situ Raman spectroscopy, X-ray photoelectron spectroscopy and Grazing incidence X-ray diffraction  measurements will be performed on the core/shell nanowires to examine various parameters such as nanowire defects, MnO2 dissolution, mechanical electrode failure behind degradation .