A Flexible All-Solid-State Asymmetric Supercapacitor Based on a Nanocomposite of Vanadium Oxide/Graphene and Polyaniline Hydrogel with Excellent Operational Stability and Energy Density
Mohammad Barazandeh, Sayed Habib Kazemi, Farzad Roohi, Dawod S. Haydar, Inger Odnevall Wallinder
Abstract
High Resolution Image Download MS PowerPoint Slide Porous polymer-based materials of high electrical conductivity are essential for a wide range of applications. An innovative nanocomposite of V 2 O 5 /rGO/polyaniline hydrogel (VG/PANi-HG) was synthesized using in situ oxidative polymerization in the presence of V 2 O 5 /rGO (VG) and phytic acid on a carbon fiber substrate. Subsequently, the corresponding electrode was employed as a flexible free-standing electrode and examined through a range of electrochemical methods to assess its performance in high-rate supercapacitors. The VG/PANi-HG supercapacitor demonstrated an excellent specific capacitance of 982 F g –1 at a current density of 2.7 A g –1 . Furthermore, an asymmetric all-solid-state (ASC) device was assembled using VG/PANi-HG as a positive electrode in combination with a graphene oxide electrode as a negative electrode and a polyvinyl alcohol (PVA) hydrogel electrolyte. This flexible asymmetric device exhibited an impressive cycle life stability and a power density of 2 kW kg –1 at an energy density of 29.44 Wh kg –1 . Our results reveal that the VG/PANi-HG electrode material is a promising candidate for future electrochemical energy storage devices.