Tungsten disulfide-nickel oxide hybrids as high-performance supercapacitors

Abstract

Two-dimensional materials are suitable for energy storage applications due to their chemical stability, high electrical conductivity and large specific surface area. In this work, tungsten disulfide (WS2) nanosheets were synthesized by chemical exfoliation method and combined with nickel oxide (NiO) nanoparticles to be used as a working electrode for storing energy. The WS2 electrode alone shows a capacitance of about 21.87 mF⸳cm-2, which is improved up to 64.58 mF⸳cm-2 by adding NiO nanoparticles. The occurrence of redox reactions plays an important role in increasing the final capacitance. Moreover, the proposed hybrid maintains 93% of its initial capacitance after 5000 charge-discharge cycles, which indicates its stable and reliable performance.

Tuning the electrochemical properties of NiS2 2D-nanoflakes by one-zone sulfurization for supercapacitor applications

“…Thanks to their chemical and structural properties, transition metal sulfides (TMS) have been quite recently under intensive investigation for applications in different modern energy and environmental technologies. Among TMS, nickel sulfides, namely NiS and NiS 2 , have been reported as promising candidates for Li-ion batteries, supercapacitors, and water splitting electrodes [1][2][3][4]. The excellent electrical conductivity, high theoretical capacitance, large active sites, non-tocity and abundant availability in nature, as well as achieved fast charge and discharge rates and impressive cycle life of NiS and NiS 2 based structures makes these materials appealing for preparation of new energy storage and conversion devices with unique properties and high performance [5][6][7].…”