Synergetic electrochemical performance of tungsten oxide/tungsten disulfide/MWCNTs for high-performance aqueous asymmetric supercapattery devices

Abstract

In this work, a binary WO3/WS2 nanocomposite is synthesized by a single-step sulfurization of WO3 through chemical vapor deposition (CVD) process. Then the synthesized composite was blended with MWCNTs to produce a WO3/WS2/MWCNTs ternary composite for a high-performance supercapacitor. X-ray diffraction, Raman, and X-ray photoelectron spectroscopy were used to investigate comprehensively structural characteristics and chemical bonding of the synthesized nanocomposite. FESEM reveals that agglomeration of 1D MWCNTs, and 2D WS2 nanosheets with WO3 nanoparticles enhance the surface area as well as conductivity of electrode material which in turn leads to superior electrochemical properties of the ternary nanocomposite. The electrochemical measurements suggest that the WO3/WS2/MWCNTs composite is the best-optimized electrode with a specific capacitance of 517 C/g. By employing the optimized electrode as positive and activated carbon (AC) treated as a negative electrode an asymmetric supercapattery (ASC) device was assembled. The ASC device displays a high energy density of 86 Wh/kg and power density of 11828 W/kg with only 5 % degradation in initial capacitance after 5000 continuous cycles. In conclusion, composting is a promising approach to boost the overall performance of supercapacitors.