Nickel-Cobalt Hydroxide Nanosheets Coated on NiCo2O4 Nanowires Grown on Carbon Fiber Paper for High-Performance Pseudocapacitors

A series of flexible nanocomposite electrodes were fabricated by facile electro-deposition of cobalt and nickel double hydroxide (DH) nanosheets on porous NiCo2O4 nanowires grown radially on carbon fiber paper (CFP) for high capacity, high energy, and power density supercapacitors. Among different stoichiometries of CoxNi1xDH nanosheets studied, Co0.67Ni0.33 DHs/NiCo2O4/CFP hybrid nanoarchitecture showed the best cycling stability while maintaining high capacitance of similar to 1.64 F/cm(2) at 2 mA/cm(2). This hybrid composite electrode also exhibited excellent rate capability; the areal capacitance decreased less than 33% as the current density was increased from 2 to 90 mA/cm(2), offering excellent specific energy density (similar to 33 Wh/kg) and power density (similar to 41.25 kW/kg) at high cycling rates (up to150 mA/cm(2)).