LAUSR

Abstract Herein, two different nanoscale hybrid ionic fluids (NHIFs) have been demonstrated as potential electrolytes for electrochemical cyclic applications. These NHIFs are prepared by tethering 1-ethyl-3-(3-trimethoxysilylpropyl)-imidazolium bis(trifluoromethanesulfonyl)imide ionic liquids to the surfaces of SiO 2 and Al 2 O 3 nanoparticulate cores by simple sol–gel process, resulting in a class of versatile, stable and high-performance gel like materials. Both the NHIFs are mechanically compliant and thermally stable. The NHIFs show wide electrochemical stability window of 8 volt that does not shrink with the increase of temperature. Furthermore, the NHIF electrolytic cells containing planar steel electrodes show very good capacitance retentivity (>90%) and long term cyclic stability above room temperature. Relatively higher grafting density of the ionic liquid chains to SiO 2 nanoparticles as compared to Al 2 O 3 nanoparticles enables the respective NHIF to show better morphology with superior thermal, mechanical, electrical and electrochemical properties than its Al 2 O 3 tethered analogue. Results obtained from the study highlight the applicability of these hybrid ionic fluids as promising electrolytes in secondary charge storage devices, even at higher temperature.