NiO Hybrid Nanoarchitecture Based Symmetric Supercapacitor in Non-Aqueous Electrolytes with Improved Rate Capability and Cycle Life

A three dimensional hierarchical NiO nanostructures with combined microstructure of nanoflakes and nanoflowers have been fabricated on carbon fiber cloth (CFC). Unique nano-micro structural features of NiO electrode exhibit an excellent electrochemical activity as electrode material for symmetric supercapacitors in non-aqueous organic electrolyte (1 M TEABF₄ in propylene carbonate). The NiO/CFC electrode showed an enhanced electrochemical activity in organic electrolyte in terms of rate capability, specific energy and power performance, as well as potential limit. The symmetric supercapacitor showed a specific capacitance of 34.9 F/g at 1 A/g current density in organic electrolyte. The hybrid electrode delivered a maximum specific energy density of 19.4 Wh/kg at a high power density of 1002.8 W/kg in 1 M TEABF₄/PC at a constant current density of 1 A/g. The cell is also capable of good reversibility with a cycling efficiency of 58% after 25000 cycles. This superior electrochemical activity of the NiO electrode is due to their structural benefits of well-connected hybrid nano/mesoporous structure and rapid ion intercalation within the porous electrode surface.