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

We report the fabrication and performance of zinc oxide core/manganese oxide shell (ZnO/MnO₂) 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 MnO₂ nanostructure on ZnO nanorods. The quality of the ZnO/MnO₂ electrode was optimized by performing various cycles of SILAR deposition of MnO₂ layer over ZnO core. The electrode with 7 cycles of MnO₂ 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/MnO₂ 3D architecture planar supercapacitor showed maximum area capacitance of 5 mF cm⁻² in 1 M Na₂SO₄ 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.