Novel organosilicon ionic liquid based electrolytes for supercapacitors

Abstract

A novel room temperature organosilicon ionic liquid (SiN1IL) was synthesized and its chemical structure and electrochemical window were characterized. The ionic conductivity of SiN1IL/propylene carbonate (PC)/acetonitrile (AN) solution was 19.6 mS· cm -1, comparable with the commercial electrolytes currently used in supercapacitors. The electrochemical performance of the cells using activated carbon as electrodes and SiN1IL-based formula with PC/AN as electrolytes was systematically evaluated. SiN1IL/PC electrolyte exhibited superior rate capability and lower impedance compared to a conventional electrolyte (tetraethylammonium tetrafluoroborate (Et 4NBF 4)/PC). Upon applying a working voltage of 2.7 V, the SiN1IL/PC cell had a specific capacitance of 108 F · g -1 at a current density of 1000 mA · g -1. © Editorial office of Acta Physico-Chimica Sinica.