High performance and remarkable cyclic stability of a nanostructured RGO–CNT-WO3 supercapacitor electrode

Abstract

One of the most pressing concerns in today's power networks is ensuring that consumers (both home and industrial) have access to efficient and long-lasting economic energy. Due to improved power accessibility and high specific capacitance without deterioration over long working times, supercapacitor-based energy storage systems can be a viable solution to this problem. So, here, tungsten trioxide (WO₃) nanocomposites containing reduced graphene oxide and carbon nanotubes i.e. (RGO-WO₃), (CNT-WO₃), and (RGO–CNT-WO₃), as well as pure WO₃ nanostructures as electrode materials, were synthesized using a simple hydrothermal process. The monoclinic phase of WO₃ with high diffraction peaks is visible in X-ray diffraction analysis, indicating good crystallinity of all electrode materials. Nanoflowers of WO₃ were well-decorated on the RGO/CNTs conductive network in SEM micrographs. In a three-electrode system, the specific capacitance of the RGO–CNT-WO₃ electrode is 691.38 F g⁻¹ at 5 mV s⁻¹ and 633.3 F g⁻¹ at 2 A g⁻¹, which is significantly higher than that of pure WO₃ and other binary electrodes. Furthermore, at 2 A g⁻¹, it achieves a coulombic efficiency of 98.4%. After 5000 cycles, RGO–CNT-WO₃ retains 89.09% of its capacitance at 1000 mV s⁻¹, indicating a promising rate capability and good cycling stability performance.