Core/sheath structured ultralong MnOx/PPy nanowires feature improved conductivity and stability for supercapacitor

Abstract Increased conductivity of manganese oxide (MnOx) for effectively improved supercapacity is studied in this work by addressing on introduced oxygen vacancies (OVs) besides a porous sheath of conductive polymer (polypyrrole, PPy). The assembly profile of core/sheath structured MnOx/PPy nanowires by in-situ polymerization of PPy under mild condition showing better conductivity, specific capacitance, rate performance and cycling stability than so far reported MnOx based materials. Structural characteristics of the MnOx/PPy nanowires are studied in detail, including high weight percent of MnOx core, underlying PPy layer chemically bonding MnOx core and PPy nanoparticles in outlayer, as well as the simultaneously introduced conductive oxygen vacancies (OVs) in MnOx during formation of PPy sheath. The contribution of assembly profile to the supercapacitor performances is discussed, especially concerning PPy sheath and OVs, essentially yielding improved conductivity between current collector and the MnOx core to assure large energy density and power density.