Pseudocapacitive nanostructured silver selenide thin film through room temperature chemical route: First approach towards supercapacitive application

Abstract

Well controlled growth of pseudocapacitive nanostructured silver selenide (Ag2Se) thin film has been achieved through simple, less expensive, room temperature and industry scalable successive ionic layer adsorption and reaction (SILAR) method onto stainless steel substrate to use as electrode material for supercapacitor application as the first report. X-ray photoelectron spectroscopy studies confirmed the formation of Ag2Se. Orthorhombic structure of grown Ag2Se thin film exhibits hydrophilic nature in aqueous Na2SO3 electrolyte yielding specific capacitance of 112.45 F/g @ 10 mV/s scan rate studied through cyclic voltammetry (CV) and 115.99 F/g @ 0.8 A/g by galvanostatic charge discharge through electrochemical studies. Interestingly Ag2Se electrode exhibits 85.10 % capacitive retention after 2000 CV cycles. Origin of net-charge stored at the electrode–electrolyte interface has been well understood from surface induced capacitive and diffusion-controlled mechanisms. Low equivalent series resistance (ESR) value of 0.06 Ω was determined by the plot of iRdrop vs. current density exhibiting high-power burst electrode material.