Conductivity, viscosity, and solubility measurements

Impedance spectroscopy was used to measure the ionic conductivity of the electrolytes containing ROMs. The house-made dip-in conductivity cell consisting of two platinum disks was used. Viscosities were measured using a VISCOlab4000 Laboratory Viscometer (Cambridge Viscosity). The sample chamber was thermostated at 30 °C during the measurements (see Supplementary Table 2). For solubility measurements at 35 °C, samples containing different concentration of ROMs were transferred into a 96-well quartz plate after being stirred at this temperature in sealed vials for 1 hour. They were then investigated using a dynamic light scattering analyzer equipped with an optical camera and a temperature controller (DynaPro Plate Reader II, Wyatt Technologies). The assessment was performed using the images of each well.