Concentrated Sodium Bis(fluorosulfonyl)amide Aqueous Electrolyte Solutions for Electric Double-layer Capacitors

Here, highly concentrated sodium bis(fluorosulfonyl)amide (NaFSA) aqueous electrolytes were examined for the aqueous electrolytes of electric double-layer capacitors with wide potential window. Firstly, fundamental properties of electrolytes were investigated using conductivity measurements and Raman spectroscopy. During cyclic voltammetry of activated carbon electrodes, aluminum corrosion was observed for positive electrode side. After current collectors of positive electrodes were changed to titanium, capacitor reactions were confirmed for both of positive electrode and negative electrode sides in NaFSA aqueous electrolytes. In addition, resistances of activated carbon electrodes in NaFSA aqueous electrolytes were smaller than those in LiTFSA aqueous electrolytes.