NiO/Ni Nanowafer Aerogel Electrodes for High Performance Supercapacitors

Abstract

Transition metal oxide aerogels are a fascinating class of compounds that have received considerable attention in the last decade owing to their unique and exceptional properties, including high porosity, large surface area, and ultralow density. In this study, α-Ni(OH)2 aerogels and annealed NiO/Ni aerogels were used to design and fabricate a two-electrode supercapacitor device. The physicochemical properties of the as-synthesized aerogels were characterized through X-ray diffraction, scanning electron microscopy, transmission electron microscopy, the Brunauer–Emmett–Teller theory, and X-ray photoelectron spectroscopy studies. The annealed NiO/Ni aerogels showed a (specific capacitance of 1060 F/g) specific capacity of 422 C/g at 1 A/g current density and with good cycling stability (up to 10,000 cycles). The supercapacitor also demonstrated an energy density of 32.4 Wh/kg and power density of 1800 W/kg at a current density of 2 A/g. The specific capacitance of NiO/Ni aerogels was more than twice that of the α-Ni(OH)2 aerogels. The practical applications of the aerogel were demonstrated by fabricating a two-electrode device.

Self-Powered Broadband Photodetector Based on NiO/Si Heterojunction Incorporating Graphene Transparent Conducting Layer

“…The 23 nm of RMS roughness of the spin-cast NiO observed from the AFM image indicates that the NiO nanosheet has a mean thickness higher than that of 23 nm, as shown in Figure 2 b. The XPS spectra of the NiO before and after graphene transfer, as presented in Figure 2 c, shows the two distinct Ni 2p 3/2 and Ni 2p 1/2 peaks observed at around 855 and 873.2 eV, respectively; in addition, their corresponding satellite peaks observed at a slightly higher binding energy for the NiO nanoparticles confirms that the NiO quality remains the same after the graphene transfer process [ 38 , 39 , 40 ]. Figure 2 d shows the transmittance spectra of the spin-coated NiO nanoparticles on both sides of the polished sapphire substrate from 300 to 800 nm by considering both sides of the polished sapphire substrate as a reference baseline.…”

MOF-Derived Ultrathin NiCo-S Nanosheet Hybrid Array Electrodes Prepared on Nickel Foam for High-Performance Supercapacitors

“…Then, on the basis of the GCD data, the SC ( , F∙g −1 ) of the electrode materials was calculated by the following formulas [ 7 , 10 ]:…”

“…Finally, the prepared AC electrode was dried at 60 °C for 12 h and drenched in 6 M KOH solution overnight for electrochemical tests. Meanwhile, to maintain the conservation of positive and negative charges in the HSC device for enhancement of the electrochemical performance, the mass ratio of the positive and negative electrodes was balanced using the following formula [ 7 ]: where (g), (V), and (F∙g −1 ) represent the mass, potential range, and SC of the negative electrode, respectively; (g), (V), and (F∙g −1 ) denote the mass, potential range, and SC of the positive electrode, respectively. In light of the charge conservation in the formula, the mass ratio of positive and negative materials was 1:1.63.…”

“…Finally, the prepared AC electrode was dried at 60 • C for 12 h and drenched in 6 M KOH solution overnight for electrochemical tests. Meanwhile, to maintain the conservation of positive and negative charges in the HSC device for enhancement of the electrochemical performance, the mass ratio of the positive and negative electrodes was balanced using the following formula [7]:…”

“…The electrode materials, as the key component of supercapacitors, produce an essential effect on their service performance. Transition metal compounds (oxides, hydroxides, and sulfides) as promising electrode materials have attracted extensive attention owing to their low manufacturing cost, simple synthesis process, high theoretical specific capacity, and high energy density [ 4 , 5 , 6 , 7 ]. Moreover, they could provide enough storage charge during their contact reactions with the electrolyte owing to their varieties of chemical valence states [ 8 ].…”