Fabrication of Three-Dimensional Porous NiO/Amorphous Ni(OH)₂ Composites for Supercapacitors

Abstract

Three-dimensional porous NiO/Ni(OH)2 composites consisting of NiO nanoparticles and amorphous Ni(OH)2 nanosheets were prepared successfully for supercapacitors. NiO nanoparticles were dispersed uniformly among Ni(OH)2 nanosheets. The capacitance of the composites reached 1375.45 F g–1 at 0.5A g–1, which was much higher than that of pure NiO and Ni(OH)2. After 1000 cycles, 95.5% of the capacitance of composites was retained. Moreover, an NiO/Ni(OH)2-2//AC device was fabricated and exhibited a prominent energy density of 28.5 Wh kg–1 at a power density of 450 W kg–1 and even 13.8 Wh kg–1 at 2258.2 W kg–1. A light-emitting diode can easily be lit using the device, demonstrating its application. The enhanced capacitance performance of the NiO/Ni(OH)2 hierarchical structure was ascribed to its tremendous surface area and amorphous characteristics.