An asymmetric supercapacitor based on controllable WO₃ nanorod bundle and alfalfa-derived porous carbon

Abstract

A asymmetric supercapacitor is assembled on the basis of an inerratic hexagonal-like WO3 nanorod bundle as a negative electrode and graphene-like alfalfa-derived porous activated carbon as the positive electrode in 1 M H2SO4 aqueous electrolyte.

A study on the effect of phase conversion of tungsten nanostructures on their electrochemical energy storage performance

“…The growth mechanism of the different morphologies of WO 3 /WO 3− x can be explained according to the following equations 45 Na 2 WO 4 ·2H 2 O ⇒ 2Na + + WO 4 2− + 2H 2 O2Na + + WO 4 2− + 2HCl ⇒ H 2 WO 4 + 2NaClH 2 WO 4 ⇒ WO 3 (crystal nucleus) + H 2 OWO 3 (crystal nucleus)/WO 3 (different morphologies)…”

“…The electrochemical charge storage mechanism of WO 3 /W0 3− x in KOH electrolyte can be expressed using eqn (5) as: 45 WO 3 + x K + + x e − ⇒ K x WO 3 .…”

“…A similar observation was reported for the SnS based material in 2020. 44 The growth mechanism of the different morphologies of WO 3 /WO 3Àx can be explained according to the following equations 45 Na 2 WO The incomplete sulfidation of the tungsten oxide resulted in the morphological deviation of plate-like TMO to nanorods of the composite WO 2.72 : WS 2 . The complete sulfidation of tungsten oxide favours the formation of sulfide layers over the TMO.…”

Recent advancements in 3D porous graphene-based electrode materials for electrochemical energy storage applications

“…A device with the combined characteristics of both systems (battery and supercapacitor) are expected to achieve high power density and high energy density simultaneously. In this context, there is growing research interest in asymmetric and hybrid supercapacitors [82,83],…”

Engineering of Nanostructured WO3 Powders for Asymmetric Supercapacitors

“…Our data span a very wide range of performances with many experimental points, which is a key feature for the maximization of E d and P d . The E d and P d obtained in the present case are higher than those of several previously reported ASC based on WO 3 -WO 3 0.5H 2 O mixtures (23.4 W × h/kg at 5200 W/kg, orange ball) [ 24 ], RuO 2 /h-WO 3 nanorods (20 W × h/kg at 400 W/kg and 15 W × h/kg at 4000 W/kg green balls) [ 25 ], carbon–WO 3 nanocomposite (35 W × h/kg at 200 W/kg and 18 W × h/Kg at 10,000 W/kg, yellow balls) [ 29 ], WO 3 nanorods bundles (27 W × h/kg at 403 W/Kg and 14 W × h/kg at 7529 W/kg, violet balls) [ 35 ]. These promising results can be ascribed to the good agreement between the highly pure hexagonal crystal structure and the urchin-like morphology, which allows us to increase the electrolyte exposed surface, as well as the wettability of WO 3 -based electrodes.…”