An Artificial Interface for High Cell Voltage Aqueous-Based Electrochemical Capacitors

Aqueous electrolytes are very effective for supercapacitor applications but their narrow electrochemical potential window (∼1 V) and associated limited energy currently limits use. Here, we demonstrate a new strategy to enlarge the by designing an artificial interface ( ai ). An was achieved via mixture of siloxanes doped with ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMI TFSI). Indeed, as-deposited on carbon-based electrode hinders electron charge transfer not transfer, making conductive. As result, cell voltage about 1.8 V obtained in aqueous electrolyte-EMI HSO 4 1 mol l −1 water. Used as membrane, found be ionically specific EMI + ; proton transference number being close zero. These results show developing at electrode/electrolyte could represent path aqueous-based carbon-carbon supercapacitors reach higher voltages, providing both power.