Two-Dimensional Tungsten Oxide/Selenium Nanocomposite Fabricated for Flexible Supercapacitors with Higher Operational Voltage and Their Charge Storage Mechanism

Abstract

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 WO 3 /Se) nanocomposite. For this, the 2D WO 3 /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 H 2 SO 4 and 1-butyl-3-methyl imidazolium tetrafluoroborate room temperature ionic liquid (BmimBF 4 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 H 2 SO 4 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−H 2 SO 4 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 .

Uniquely Designed Tungsten Oxide Nanopetal Decorated Electropsun PAN Nanofiber for a Flexible Supercapacitor with Ultrahigh Rate Capability and Cyclability

“…Both of the samples show typical type IV isotherm with a pronounced type H1 hysteresis loop, which could be attributed to the feeble interaction between the adsorbent and adsorbate, that might have resulted in the incomplete monolayer formation on its surface. 4,21 The specific surface areas of W-PAN and WO 3 •H 2 O were obtained as 6.95 and 6.70 m 2 g −1 , respectively, and no adsorption of N 2 is observed at relative pressure value less than 0.65. Further, the adsorption quantity is also low as the relative pressure approaches 1.0.…”

“…1−6 However, because of their intermittent nature, time limitations, and climate-dependence constraints, there is an acute need for efficient and reliable energy conversion and storage technologies in order to fulfill long-term energy consumptions. Over the past decades, tremendous progress has been made to generate advanced energy storage systems such as metal-ion batteries, 2,3 electrochemical supercapacitors, 4 and redox flow batteries, along with highly efficient energy conversion devices such as fuel cells, photovoltaics, and electrolysis. 5,6 Among the numerous available energy technologies, electrochemical energy technology, especially batteries and supercapacitors (SCs), is the most promising alternative and a key representative for electrochemical energy storage (EES) systems, owing to the high efficiency, safety, and economic viability.…”

“…An immense rise in environmental pollution and the finite availability of fossil fuels are constantly propelling the research community to lean toward clean and renewable energy sources. − However, because of their intermittent nature, time limitations, and climate-dependence constraints, there is an acute need for efficient and reliable energy conversion and storage technologies in order to fulfill long-term energy consumptions. Over the past decades, tremendous progress has been made to generate advanced energy storage systems such as metal-ion batteries, , electrochemical supercapacitors, and redox flow batteries, along with highly efficient energy conversion devices such as fuel cells, photovoltaics, and electrolysis. , …”

Dual Metal-Loaded Porous Carbon Materials Derived from Silk Fibroin as Bifunctional Electrocatalysts for Hydrogen Evolution Reaction and Oxygen Evolution Reaction

“…The O 1s spectrum (Figure 8c) can be deconvoluted into three peaks centered at 531, 531.7 eV, and 532.6 eV, which can be assigned to the lattice oxygen and W−OH and O 2− ion in oxygen accordantly. 56,57 Typically, there are three types of N atoms in the N-doped carbon. Graphitic N connects with three carbon atoms in the carbon network.…”

Exploration of a Bimetallic NiSe2@CoSe2 Nanosphere as a Proficient Electrode for Electrochemical Activity

“…Nevertheless, transition metal oxides/hydroxides and sulfides have been extensively surveyed, which frequently limit the power performance. , Therefore, transition metal selenides are designed as new electrode materials owing to their stunning electrochemical performance, affluent redox sites, lower band gaps, and first-rate conductivity that limits the ionic diffusion pathway. − Generally, selenium is an attractive new research hotspot due to its distinct morphology with tunable chemical composition, suspending self agglomeration, which robustly increases the electrochemistry of the active electrode. , Currently, the blend of the composite electrode affords enhanced specific capacitance synergistically compared to single-component counterparts. Herein, the present work focused on incorporating both Ni and Co ions to obtain good electrochemical properties.…”