Electrochemical Properties of Aqueous Electric Double Layer Capacitors using Sodium Polyacrylate

Abstract

Electric double layer capacitors (EDLCs) are attracting attention as a type of storage battery with high-speed charge-discharge and long life. However, the withstand voltage of the aqueous electrolyte is approximately 1.2 V, which is the voltage at which electrolysis of water occurs, and there is a problem that it lacks energy density. In this study, sodium polyacrylate was added to the electrolyte to gelatinize it and prevent electrolysis of water, thereby improving the withstand voltage up to 3.5 V and obtained energy density of 4.6 Wh/kg.