Al(TFSI)₃ as a Conducting Salt for High-Voltage Electrochemical Double-Layer Capacitors

Abstract

In this study, we report for the first time about the use of aluminum bis(trifluoromethanesulfonyl)imide [Al(TFSI)3] as conducting salt for electrochemical double-layer capacitors (EDLCs). We show that using this salt it is possible to realize highly concentrated electrolytes, which are able to suppress the anodic dissolution of the aluminum current collectors. Because of this ability, the use of this electrolyte makes possible the realization of EDLCs that can retain 80% of their initial performance after floating for 1500 h at 3 V (which is comparable to ∼5000000 cycles of charge and discharge at 1 A g–1).