Ionic Diffusion and Dissociation in Room-Temperature Ionic Liquids

The clarification of the degree of ionic dissociation occurring in liquid-electrolyte systems such as those used in current lithium-ion batteries is important from both, fundamental and application points of views. In the present study, based on the bond strength–coordination number fluctuation (BSCNF) model proposed by the authors, we consider the relation between the ionic diffusion and dissociation in room-temperature ionic liquids. Specifically, we show firstly, that the molar conductivity Λ is well correlated with the degree of molecular cooperativity NB defined by the BSCNF model. This correlation enables to connect the cooperativity with the degree of ionic dissociation in ionic liquids. Through the comparison between the ionic diffusion coefficients and the molar conductivity, we discuss on a possible relation between these quantities.