Porous NiCo2O4 nanostructures for high performance supercapacitors via a microemulsion technique

In this paper, porous Ni-substituted Co3O4 (ternary NiCo2O4) nano wires are synthesized via a simple microemulsion technique combined with a post thermal treatment. The as-prepared NiCo2O4 exhibits porous one-dimensional (10) nanostructure, which preserves the morphology of the precursor. Moreover, the NiCo2O4 nanowires possess large surface area (53.6 m(2) g(-1)), pore volume (0.241 cm(3) g(-1)) and pore size (16.5 nm). The porous 10 nanostructures and large surface area have huge benefits for practical applications in supercapacitors. Due to the well-aligned 10 nanowire microstructure and a higher electrical conductivity, these ternary NiCo2O4, electrodes possess high specific capacities of 1197 F g(-1) at 1 A g(-1) and capacitance retentions of 625 F g(-1) at 8 A g(-1). After 2000 cycles, the NiCo2O4 electrode can maintain 91.4% of its highest value, which demonstrates its superior cyclic stability performance. Also, the NiCo2O4 electrode exhibits high capacity retention when fast charging. These results show that the porous NiCo2O4 nanowires may be a promising electrode material for high performance electrochemical capacitors. (C) 2014 Elsevier Ltd. All rights reserved.