Regensburg 2016 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
MM: Fachverband Metall- und Materialphysik
MM 61: Functional materials IV: Batteries III
MM 61.1: Talk
Thursday, March 10, 2016, 15:45–16:00, H52
From micro- to mesoscale: The impact of occupational disorder on Li ion mobility in Li4Ti5O12 battery materials — •Hendrik H. Heenen, Christoph Scheurer, and Karsten Reuter — Chair for Theoretical Chemistry and Catalysis Research Center, Technische Universität München, Garching, Germany
Spinel-type lithium-titanium-oxide (Li4Ti5O12) is an extraordinarily safe and long-living anode material employed in commercial lithium ion batteries. To complement experimental investigations, first-principles studies are often applied to gain microscopic insight into the underlying ion transport processes and the microscopic structure. This computationally demanding approach is however challenged by the treatment of the mixed occupancy of octrahedral sites by Li and Ti ions found in Li4Ti5O12. The resulting vast configuration space is usually reduced to an idealized model, oversimplifying the investigated system. A numerically efficient, yet reliable, classical interatomic potential [1], allows for exploring the complex configuration space through extensive Monte-Carlo sampling and evaluating its electrochemical properties via molecular dynamics simulations. Our findings indicate a higher Li ion mobility with structural disorder, which is thermodynamically favored by high synthesis temperatures. We further assess the Markovian processes of the diffusion mechanism via a thorough microscopic analysis and elucidate the Li ion mobility in detail. This yields dynamic rates necessary for an extrapolation to kinetic Monte-Carlo simulations which pave the way for more quantitative predictions.
[1] M. Vijayakumar et al, J. Power Sources 196(4), 2211 (2011);