Novel fast Li-ion conductors for solid-state electrolytes from first-principles

We present a high-throughput computational screening for fast lithium-ion conductors to be used as solid-state electrolytes (SSEs). Starting with more than 30,000 experimental structures sourced from the COD, ICSD and MPDS repositories, we perform highly automated calculations using AiiDA, first at the level of density-functional theory (DFT) to identify electronic insulators. On these resulting ~1000 materials, we use molecular dynamics simulations to estimate Li-ion diffusivities using the pinball model, which describes the potential energy landscape of diffusing lithium at near DFT accuracy while being 200-500 times faster [1]. Then, we study the ~60 most promising yet-unknown fast conductors with full first-principles molecular dynamics (FPMD) simulations at several temperatures to estimate activation barriers; these are refined with neural network simulations at room temperature for the 7 fastest conductors. We further present the entire screening protocol, including the workflows where the accuracy of the pinball model is improved self-consistently, necessary to automatically run the required calculations and analyze the results.

[1] L. Kahle, A. Marcolongo and N. Marzari. Phys. Rev. Mater. 2, 65405 (2018)