Effect of lithium chloride on the density and dynamic viscosity of choline chloride/urea deep eutectic solvent in the temperature range (303.15–358.15) K

Deep eutectic solvents (DESs) have emerged as superior alternatives to ionic liquids. Lithium salt-added DES mixtures may possess favorable properties as novel electrolyte media for Li-ion batteries. Densities and dynamic viscosities of LiCl-added DES reline (constituted of salt choline chloride and H-bond donor urea in 1:2 mol ratio) mixtures up to ∼0.2 molal LiCl [m(LiCl)] in the temperature range (303.15–358.15) K are presented. Decrease in density with increasing temperature is found to follow a simple linear expression. The density of LiCl-added reline also increases linearly with increasing m(LiCl) in the investigated temperature range. The temperature dependence of the dynamic viscosity of the (reline + LiCl) mixtures follows simple Arrhenius-type expression. The dynamic viscosity of LiCl-added reline mixture at a given temperature increases exponentially with increasing m(LiCl); the exponential increase being more prominent at lower temperatures. The trends in density and dynamic viscosity with temperature and m(LiCl) for LiCl-added DES reline are rather simplistic in comparison to Li salt-added ionic liquid mixtures.