A SnO2QDs/GO/PPY ternary composite film as positive and graphene oxide/charcoal as negative electrodes assembled solid state asymmetric supercapacitor for high energy storage applications

Abstract

The work demonstrates tin oxide quantum dots/graphene oxide/polypyrrole (SnO₂QDs/GO/PPY) ternary composite deposited on titanium foil as a positive electrode and graphene oxide (GO)/charcoal on titanium foil as negative electrode separated by polyvinyl alcohol/potassium hydroxide (PVA/KOH) gel-electrolyte as a solid-state asymmetric supercapacitor for high energy storage applications. Here, tin oxide quantum dots (SnO₂QDs) were successfully synthesized by a hydrothermal technique, and SnO₂QDs/GO/PPY ternary composite was synthesized by an in situ method with pyrrole monomer, SnO₂, and GO. A pH value controlled, which maintained the uniform size of SnO₂QDs dispersed on PPY, through GO ternary composite was used for fabricating the asymmetric supercapacitor electrode with the configuration (SnO₂QDs/GO/PPY)/GO/charcoal (85 : 10 : 5). The device achieved the highest specific capacitance of 1296 F g⁻¹, exhibited an energy density of 29.6 W h kg⁻¹ and the highest power density of 5310.26 W kg⁻¹ in the operating voltage from 0 to 1.2 V. The device also possessed excellent reliability and retained the capacitance of 90% after 11 000 GCD cycles. This ternary composite is a prominent material for potential applications in next-generation energy storage and portable electronic devices.