Novel Materials for solid-state electrolyte applications


Leonid Kahle (EPFL)
Giuliana Materzanini (EPFL)
Aris Marcolongo (now at IBM)


Our focus is to understand the fundamental microscopic mechanisms driving ionic diffusion in solid-state structures, and use this knowledge to engineer materials for electrolyte applications. Solid-state electrolytes are safe and performing alternatives to current state-of-the-art liquid electrolytes in lithium-ion batteries. To achieve this goal we are working on:

  • Accelerating first-principles molecular dynamics: An accurate, general, but computationally demanding approach to estimate ionic conductivities is a solid-state structures is the simulation of the time-evolution of the system via molecular dynamics in the framework of density functional theory. This is resource-limited to the study of few materials. For high-throughput screening applications, we have developed a new 'pinball' model that can be used in molecular dynamics. In this model, lithium or other diffusing cations are treated as core charges moving through a fixed charge density and host-lattice. Due to these approximations, we achieve computationally inexpensive that still retain the required accuracy [1]
  • Automatized transport coefficients: For an estimate of transport coefficients from molecular dynamics trajectories, experience, supervision and advanced analysis tools are required. We aim at developing open-source tools, based on the AiiDA platform, to automatize this cumbersome procedure and converge transport coefficients to a user-defined accuracy with minimal intervention, while retaining full provenance of the results.
  • First-princples studies of diffusion: The underlying mechanism can be studied and elucidated through the simulation of the system with first-principles molecular dynamics. Such study has shown interesting correlation effects in one of the best lithium-ionic conductors LiGePS [2] and was also used to understand the mechanism of proton diffusion in Y-doped BZO [3].




From a CIF-file to the diffusion within AiiDA High-throughput screening for novel lithium-ion conductors for solid-state electrolytesLithium diffusing in LiLaZrO, a typical garnet structure