Two-Dimensional Planar Supercapacitor Based on Zinc Oxide/Manganese Oxide Core/Shell Nano-architecture

Abstract We report the fabrication and performance of zinc oxide core/manganese oxide shell (ZnO/MnO 2 ) three-dimensional nanostructured planar supercapacitor. In this particular fabrication, ZnO nanorods were grown over FTO substrate followed by the successive ionic layer adsorption and reaction (SILAR) deposition of MnO 2 nanostructure on ZnO nanorods. The quality of the ZnO/MnO 2 electrode was optimized by performing various cycles of SILAR deposition of MnO 2 layer over ZnO core. The electrode with 7 cycles of MnO 2 deposition demonstrated maximum electrochemical performance with area capacitance of 14 mF cm −2 and the same condition was utilized for the fabrication of a symmetric planar supercapacitor. This ZnO/MnO 2 3D architecture planar supercapacitor showed maximum area capacitance of 5 mF cm −2 in 1 M Na 2 SO 4 aqueous electrolyte with good energy density of 4.07 × 10 −7  Wh cm −2 and power density of 3.19 mW cm −2 . Moreover, this planar supercapacitor shows an excellent electrochemical performance with comparable long term cyclic stability.