Mechanistic understanding of the correlation between structure and dynamics of liquid carbonate electrolytes: impact of polarization.

Liquid electrolyte design and modelling is an essential part of the development of improved lithium ion batteries. For mixed organic carbonates (ethylene carbonate (EC) and ethyl-methyl carbonate (EMC) mixtures)-based electrolytes with LiPF as salt, we have compared a polarizable force field with the standard non-polarizable force field with and without charge rescaling to model the structural and dynamic properties. The result of our molecular dynamics simulations shows that both polarizable and non-polarizable force fields have similar structural factors, which are also in agreement with X-ray diffraction experimental results.

Experimentally Driven Automated Machine-Learned Interatomic Potential for a Refractory Oxide.

Understanding the structure and properties of refractory oxides is critical for high temperature applications. In this work, a combined experimental and simulation approach uses an automated closed loop via an active learner, which is initialized by x-ray and neutron diffraction measurements, and sequentially improves a machine-learning model until the experimentally predetermined phase space is covered. A multiphase potential is generated for a canonical example of the archetypal refractory oxide, HfO_{2}, by drawing a minimum number of training configurations from room temperature to the liquid state at ∼2900 °C.

Specific ion effects for polyelectrolytes in aqueous and non-aqueous media: the importance of the ion solvation behavior.

We present the results of atomistic molecular dynamics simulations with regard to specific ion effects in water, methanol and N,N-dimethylacetamide (DMAc). As a reference system, we introduce rigid and rod-like models of polyanions and polycations in combination with alkali metal cations and halide anions as counterions. Pronounced specific ion effects can be observed in terms of the individual anion and cation condensation behavior.

Preferential solvation and ion association properties in aqueous dimethyl sulfoxide solutions.

We study the solvation and the association properties of ion pairs in aqueous dimethyl sulfoxide (DMSO) solution by atomistic molecular dynamics (MD) simulations. The ion pair is composed of two lithium and a single sulfonated diphenyl sulfone ion whose properties are studied under the influence of different DMSO concentrations. For increasing mole fractions of DMSO, we observe a non-ideal behavior of the solution as indicated by the derivatives of the chemical activity.

Local water dynamics around antifreeze protein residues in the presence of osmolytes: the importance of hydroxyl and disaccharide groups.

Antifreeze proteins (AFP) and antifreeze glycoproteins (AFGP) are synthesized by various organisms to enable their cells to survive low temperature environments like in the polar regions. The presence of antifreeze proteins leads to a temperature difference between the melting and freezing point of the solution known as thermal hysteresis. It is nowadays common knowledge that the antifreeze activity of AFPs is mainly determined by a short-range effect which includes a direct binding to the ice phase.