State-independent ionic conductivity
Joyce Barclay, Joseph Williamson, H. Litt, Stephen J. Cowling, Karina Shimizu, Adilson A. Freitas, Silvio Poppe, Jiří Šturala, Yulong Sun, Michal Kohout, Alyssa‐Jennifer Avestro, José N. Canongia Lopes, Chris Groves, J.C. Jones, Paul R. McGonigal
Abstract
Liquids lend themselves to high ionic conductivities because of their molecular-level positional and orientational disorder, which enables the free movement of ions. However, there is an unavoidable steep drop in ionic conductivity upon phase transition from a fluid state to the more ordered solid state. Here, we describe organic salts that maintain the same ionic conductivity mechanism across transitions between three states of matter, from an initial isotropic liquid to a liquid crystalline state and then to a crystalline solid. We achieved this property by minimizing the ion-pairing interactions between mobile ions and highly diffuse counterions that assemble in a stepwise manner to preserve conformational flexibility across phase transitions. This state-independent ionic conductivity opens up opportunities to exploit liquid-like ionic conductivity in organic solids.