Diameter effect of silver nanowire doped in activated carbon as thin film electrode for high performance supercapacitor

Abstract

This study used activated carbon doped with one-dimensional silver nanowires with different diameters as the electrode paste for electric double-layer capacitors and used ultrasonic spray coating to fabricate thin-film electrodes. The paste can be refined through the ultrasonic shock frequency in ultrasonic spraying, which is a technology that can effectively increase the specific surface area and porosity of activated carbon, and is favorable for the adsorption–desorption of ions in the electrolyte to achieve higher charge storage. For electrochemical analysis, the working potential window was set between −0.75 and 0.75V for cyclic voltammetry and galvanostatic charge–discharge. Electrochemical impedance spectroscopy and cycle count were measured. The experimental results of the prepared film electrodes with silver nanowires of different diameters showed that the silver nanowire that is doped solely with activated carbon electrode paste as the conductive material can improve the supercapacitor’s electrochemical properties. The undoped 186Fg−1 increased by 38.7% to 258Fg−1, whereas the charge-transfer resistance dropped by 35.7%. Moreover, after 1000 cycles of testing, 93.2% of the capacitance value was retained. It proved that activated carbon-film electrodes doped with 500nm silver nanowires can improve the capacitance and stability of the supercapacitor.