Preparation of Manganese Thin Film in Room-Temperature Butylmethylpyrrolidinium Bis(trifluoromethylsulfony)imide Ionic Liquid and Its Application for Supercapacitors

Abstract

The butylmethylpyrrolidinium bis(trifluoromethylsulfony)imide ionic liquid was found to have a very wide potential window of , making it capable of being a medium for electrodepositing metallic Mn thin film. By using an electrochemical process, block manganese counter electrode was dissolved in the ionic liquid to generate divalent Mn, which was subsequently cathodically deposited on the nickel substrate. The current efficiency of this process was confirmed to be extremely high (close to 100%). The Mn thin film can be oxidized to manganese oxide by cyclic voltammetry in electrolyte. The obtained manganese oxide exhibited an excellent pseudo-capacitive performance and possessed a satisfactory specific capacitance of at a moderate cyclic voltammetric sweep rate of .