A lattice-hole theory for conductivity in ionic liquid mixtures: application to ionic liquid + water mixtures.

We derive a new expression for the conductivity of ionic liquid-solvent mixtures. The underlying theory is based on a lattice-hole model, which incorporates the concept of site availability in order to model decreasing mobility in the mixture, as the ionic liquid concentration increases. We compare with aqueous ionic liquid mixtures, as water is a solvent which best fulfills the approximations inherent in our theory. The conductivity expression is couched in terms of a single-fitting parameter and is able to reproduce a range of conductivity data with good accuracy.