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.