High-throughput microwave synthesis and characterization of NiO nanoplates for supercapacitor devices

In order to produce economically viable supercapacitor devices for electrical energy storage, low cost, and high throughput methods must be developed. We developed a microwave based synthesis for the formation of β-Ni(OH)₂ for the formation of nickel oxide nanoplates. These nanoplates have shown excellent properties as pseudocapacitive devices with high-specific capacitance. Novel to this article is the use of a microwave reactor which enables a growth process of only 10 min in duration as compared to previous reports requiring a 24 h period. The resulting NiO nanoplates were fully characterized by electron microscopy, electron diffraction, energy dispersive X-ray spectroscopy, UV–Vis spectroscopy, thermo gravimetric analysis, and surface area and porosity measurements. Nanoplates formed using the microwave reactor is similar to those formed by hydrothermal processes. NiO-single walled carbon nanotube composites were made without any binder and the specific capacitance was measured using charge discharge techniques.