Rethinking the Design of Ionic Conductors Using Meyer–Neldel–Conductivity Plot

From the discovery of first fast ionic conductor silver iodide in early 20th century to recent lithium conductors with conductivities surpassing those liquid electrolytes, high conductivity ? has often been associated low activation energy Ea following Arrhenius equation. However, Meyer–Neldel rule (MNR) indicates that and prefactor ?0 are correlated, suggesting relation between is, fact, complex. In this perspective, use Meyer–Neldel–conductivity plot a critical descriptor, ?0, guide search for is proposed. Reported lithium, sodium, magnesium categorized into three types, depending on relative magnitude ?0 thermal (kBT) at application temperature. The process by which can be optimized tuning these types elaborated. This principle widely applied all obey MNR any Furthermore, pressure-tuning approach measure rapidly developed. These findings establish previously missing step designing new improved conductivity.