Two-Dimensional Tungsten Oxide/Selenium Nanocomposite Fabricated for Flexible Supercapacitors with Higher Operational Voltage and Their Charge Storage Mechanism.
Rasmita BarikAshok Kumar YadavShambhu Nath JhaDibyendu BhattacharyyaPravin Popinand IngolePublished in: ACS applied materials & interfaces (2021)
The present work elaborates the high-energy-density, stable, and flexible supercapacitor devices (full-cell configuration with asymmetric setup) based on a two-dimensional tungsten oxide/selenium (2D WO3/Se) nanocomposite. For this, the 2D WO3/Se nanocomposite synthesized by a hydrothermal method followed by air annealing was coated on a flexible carbon cloth current collector and combined separately with both 0.1 M H2SO4 and 1-butyl-3-methyl imidazolium tetrafluoroborate room temperature ionic liquid (BmimBF4 RTIL) as electrolyte. Different physicochemical characterization techniques, viz., transmission electron microscopy, scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy, are utilized for phase confirmation and morphology identification of the obtained samples. The electrochemical analysis was used to evaluate charge storage mechanism. The half-cell configuration (three electrode system) in 0.1 M H2SO4 shows a specific capacitance of 564 F g-1 at 6 A g-1 current density, whereas with ionic liquid as electrolyte, a higher specific capacitance of 1650 F g-1 was obtained at a higher current of 40 mA and working potential of 4 V. Importantly, the asymmetric flexible supercapacitor device with PVA-H2SO4 electrolyte shows a working voltage of 1.7 V. A specific capacitance of 858 mF g-1 is obtained for the asymmetric electrode system with an energy density of 47 mWh kg-1 and a power density of 345 mW kg-1 at a current density of 0.2 A g-1.
Keyphrases
- ionic liquid
- electron microscopy
- solid state
- room temperature
- reduced graphene oxide
- single cell
- carbon nanotubes
- quantum dots
- cell therapy
- visible light
- high resolution
- gold nanoparticles
- bone marrow
- solid phase extraction
- stem cells
- heavy metals
- mesenchymal stem cells
- risk assessment
- aqueous solution
- human health
- climate change
- molecularly imprinted
- liquid chromatography