Preparation and electrochemical performance of Convolvulus arvensis-derived activated carbon for symmetric supercapacitors

•Activated carbon was prepared by simple pyrolysis of Convolvulus arvensis.•High surface area activated carbon was used as electrodes in supercapacitor.•The symmetric supercapacitor delivered a high specific capacitance of 103 F/g and an energy density of 14 Wh/kg.•The developed symmetric supercapacitor device retained high cyclic stability.