Alkali metal iodide/carbon interface as a source of pseudocapacitance

The pseudocapacitive effects originating from the alkali metal iodide/carbon interface have been studied in aqueous medium. Five different solutions, i.e., lithium, sodium, potassium, rubidium and caesium iodides (1 mol L− 1) have been tested as electrolyte in supercapacitors. The capacitance of positive electrodes operating in these solutions reached values higher than 1000 F g− 1, depending strongly on the alkali metal ion.