Porous NiCo2O4 Nanowire Arrays as Supercapacitor Electrode Materials with Extremely High Cycling Stability

Abstract

In this work, NiCo2O4(NCO) was synthesized via microwave hydrothermal method and a further annealing treatment. Research results have shown that the surface defects(Co2+ site) and pore size of the materials can be adjusted by simply changing the calcination temperatures, and porous nanowire arrays structure can be obtained. The porous structure is conducive to the penetration of the electrolyte and enables the NCO to fully participate in the electrochemical reaction. What’s more, the NCO material has ample space to buffer the volume change in the cycle test, improving the cycling stability. The NCO obtained at 350 °C has better performance. It exhibits a specific capacitance of 648.69 F/g at 1 A/g and good rate capability. Especially, at 10 A/g, the specific capacitance can still be maintained at 80.00% after 10000 galvanostatic charge/discharge(GCD) cycles, showing excellent cycling stability.