Silver-tungsten heterostructures nanocomposite for high-performance supercapacitor application

In this study, silver oxide (Ag₂O)-doped tungsten oxides (WO₃) are synthesized
via a hydrothermal route and systematically investigated as a potential electrode
material for supercapacitor applications. The structural and surface characteristics
of the synthesized materials are examined using X-ray diffraction (XRD), UV–Vis
spectroscopy, field-emission scanning electron microscopy (FESEM), high-reso
lution scanning transmission electron microscopy (HRSTEM), and X-ray photo
electron spectroscopy (XPS). Electrochemical performance is evaluated through
cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) measure
ments. The Ag₂O-doped WO₃ electrode exhibits outstanding electrochemical
behavior, delivering a high specific capacitance of 1700 F g⁻1 at a current density
of 1 A g⁻1. In addition, the electrode demonstrates notable cycling stability, retain
ing 76% of its initial capacitance after 5000 consecutive charge–discharge cycles.
To further assess its practical applicability, an asymmetric supercapacitor (ASC)
device is assembled using Ag₂O-doped WO₃ as the positive electrode and reduced
graphene oxide (rGO) as the negative electrode. The fabricated ASC delivers an
energy density of 15.7 Wh kg⁻1 and a power density of 650 W kg⁻1, indicating its
efficient energy-storage capability. Notably, two ASC devices connected in series
successfully power a blue light-emitting diode (LED) operating at 2.8 V, demon
strating the practical potential of the developed electrode material