Porous 3D honeycomb structures formed from interconnected Ni(OH2) sheets on CNT-coated hybrid framework as high-performance electrodes for supercapacitors

Abstract

Here, we report the effective hydrothermal synthesis of nickel hydroxide [Ni(OH)2] nanomaterials with a honeycomb-like structure comprising two-dimensional (2D) nanoplates formed from nanosheet arrays. According to the powder X-ray diffraction data, a composite consisting of Ni(OH)2 and carbon nanotubes was effectively created. The presence of significant vibrations of CNT and Ni(OH)2 was verified by FTIR and Raman spectra. Elements in the synthesized composite were validated by energy-dispersive X-ray analysis, and experimental and theoretical values agreed well. Specific capacitance of 1715 Fg−1 at 1 Ag−1 was attained with novel Ni(OH)2 designs incorporated over CNT Ni foam. The effectiveness of the honeycomb Ni(OH)2@CNT network device is equivalent to that of existing carbon-based and metal oxide/carbon-based solid-state supercapacitor devices, with a maximum energy density of 77.2 Whkg−1 and a power density as high as 866 Wkg−1. In particular, after 10,000 cycles, this material retains a large percentage of its original capacitance (94.4 % to be exact) while still maintaining a respectable Coulombic efficiency (84.5 %). These encouraging findings suggest these materials might be used in efficient, cheap, and safe energy storage systems.