A Descriptor for Non‐Arrhenius Ion Transport Enables Design of Sulfide Superionic Conductors

ABSTRACT Non‐Arrhenius ion transport is increasingly observed in solid electrolytes but remains difficult to compare across materials or use in screening. A curated database of 867 conductivity‐temperature entries from thio‐LISICON and LGPS‐type sulfides is used to introduce Meyer–Neldel deviation (MND), a physics‐informed, material‐level descriptor of temperature‐dependent changes in apparent activation energy. More than 40% of the analyzed sulfide electrolytes show notable deviations from linear Arrhenius behavior. MND separates low‐conductivity/high‐barrier and superionic/low‐barrier regimes associated with ionic‐radius mismatch, electronegativity difference, configurational entropy, and mixing thermodynamics, while providing a more informative learning target than single‐value activation energies. Sensitivity analyses indicate that material‐level trends remain reasonably robust to variations in conductivity, reference temperature, and sampling density. Application to a reprocessed dataset of 160 compositions and 2,410 conductivity‐temperature entries across seven electrolyte families supports broader applicability. MND‐guided screening of 171 Li 10 Ge x Si y Sn z P 2 S 12 compositions prioritizes Li 10 Ge 0.3 Si 0.15 Sn 0.55 P 2 S 12 , which exhibits a room‐temperature conductivity of 7.21 mS cm − 1 , an apparent activation energy of 0.288 eV, and weak non‐Arrhenius behavior consistent with prediction. Evaluation of a second composition further supports the multistage screening strategy. These results position MND as a chemically interpretable representation for quantifying, learning, and screening temperature‐dependent ion transport.