Materials Modelling Division

A combined experimental and theoretical study

Solid solutions of sodium bismuth titanate (NBT) belong to the most performant lead-free dielectric ceramics for energy storage. However, the defect chemistry of NBT is very complex, and acceptor doping can lead to an unexpected and extraordinarily high oxygen ionic conductivity. This can be attributed to a non-linear change in the formation of defect associates between acceptor and oxygen vacancy with increasing acceptor doping. Using different acceptor dopants with varying concentrations, we elucidate the interaction between acceptors and oxygen vacancies in this work. With the help of total energy calculations based on density functional theory and molecular dynamics simulations, the experimentally observed differences in conductivity can be rationalized.

MRS 2021 Autumn Meeting 06.12.-08.12.2021

We are delighted and congratulate our colleague Lisette Haarmann on the award she received for the best poster at this event.

An Atomistic Investigation

Understanding the nature of ion transfer at the interface between Li metal and solid electrolytes (SE) is essential for further optimization of all-solid-state Li-ion batteries. Thus, the Li transfer across the SE|Li metal interface is investigated by means of ab initio calculations based on density functional theory in this work. The aluminum-doped garnet Li 6.25 Al 0.25 La 3 Zr 2 O 12 (LLZO) is considered as a model SE due to its practical stability against Li metal. A low-energy interface model in bicrystal geometry is constructed and investigated by nudged elastic band calculations as well as ab initio molecular dynamics (AIMD) simulations.