Regensburg 2025 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 32: Transport in Materials: Diffusion, Charge or Heat Conduction

MM 32.5: Vortrag

Donnerstag, 20. März 2025, 16:00–16:15, H22

Charge Transport Simulation in the High State-Of-Charge using Kinetic Monte Carlo — •Roya Ebrahimi Viand, Chiara Panosetti, Christoph Scheurer, Karsten Reuter, and Sebastian Matera — Fritz-Haber-Institut der MPG, Berlin

Understanding charge transport in solids is crucial for improving energy storage systems such as lithium-ion batteries. The diffusion of particles in solid materials typically involves rare transitions between low-energy sites, making kinetic Monte Carlo (kMC) an effective tool for studying the long-time dynamics. To address the computational challenges posed by long-range Coulomb interactions, we utilize fast rules for updating the process rates at each kMC step. We investigate ion transport on an isotropic rectangular lattice as well as in lithium graphite structures at high states of charge. We find that small changes in the ion concentration can significantly influence ion mobility, depending on temperature and dielectric response. This happens near stoichiometric concentrations, where the ions freeze in a Coulomb superlattice where effective motion is energetically uphill. Introducing defects or excess ions then opens effective pathways for diffusion. Finally, we discuss the possibility of multiple quasi-stationary states manifesting in different mobilities under the same applied conditions and concentrations.

Keywords: Charge transport; kinetic Monte Carlo; Lithium Ion Batteries