Research

Publication: J.S. Lowe and D.J. Siegel, “Modeling the Interface Between Lithium Metal and its Native Oxide,” ACS Applied Materials & Interfaces 2020, 12, 46015-46026.

Summary:

• The interface between Li metal and its native oxide was constructed and analyzed with two types of structures: crystalline interfaces with differing chemical terminations, and an amorphous model in which the oxide layer was ‘grown’ by the stepwise oxidation of Li metal.

• The electronic structure of the interfaces was characterized using charge transfer analysis and shifts in the binding energies of the Li 1s electrons.

• Using ab initio molecular dynamics, the amorphous Li/Li₂O interface displayed facile transport of Li⁺.

Significance:

The transport of Li⁺ in the solid electrolyte interphase layer, which is crucial to the performance of Li metal batteries, may be improved by increasing the percentage of amorphous Li₂O.

Video: Addition of O₂ molecules to Li(111)

(2) Reaction Pathways for Solvent Decomposition on Magnesium Anodes

Publication: J.S. Lowe and D.J. Siegel, “Reaction Pathways for Solvent Decomposition on Magnesium Anodes,” The Journal of Physical Chemistry C 2018, 122, 10714-10724

Decomposition of DME on Mg (0001) surface

Decomposition of DME on MgO (100) surface

Decomposition of DME on MgCl2 (0001) surface

Summary:

• DFT calculations were performed to predict both the thermodynamic driving force (reaction enthalpy) and kinetics (activation energy) of plausible decomposition reactions on three Mg anode surface phases: Mg metal, MgO, and MgCl₂.

• Using Bader Charge analysis, reductive charge transfer from the metallic electrode was shown to minimize reaction barriers and stabilize decomposition products.

Significance:

The commercialization of Mg-ion batteries can be accelerated by tailoring the properties of the Mg anode surface film to limit solvent decomposition, yet allow for the rapid transport of Mg²⁺ across its thickness.

Thermal energy storage

(3) Computational Screening of Hydration Reactions for Thermal Energy Storage: New Materials and Design Rules

Publication: (ACS Editors’ Choice Article and Designated as an ACS Most Read Article for March 2018) S. Kiyabu, J.S. Lowe, A. Ahmed, and D.J. Siegel, “Computational Screening of Hydration Reactions for Thermal Energy Storage: New Materials and Design Rules,” Chemistry of Materials 2018, 30, 2006-2017.

Summary:

• 265 hydration reactions were characterized by their energy storage capacities and material properties with high-throughput DFT calculations.

• Promising reactions were identified in low (<100 °C), medium (100-300 °C), and high (>300 °C) temperature ranges, including the dehydration of CrF₃·9H₂O, which appears to be previously unexplored for TES.

Significance:

This work represents one of the largest screening studies involving hydration reactions for TES. The results can be used to guide experiments towards the most promising TES materials.

Combustion

(4) Towards a predictive model for polycyclic aromatic hydrocarbon dimerization propensity

Publication: V. Yadav, J.S. Lowe, A. Shumski, E. Liu, J. Greeley, and C.W. Li, “Modulating the Structure and Hydrogen Evolution Reactivity of Metal Chalcogenide Complexes through Ligand Exchange onto Colloidal Au Nanoparticles,” ACS Catalysis 2020, 10, 13305-13313.

Summary:

• Using combined experimental/computational investigations, we show how the electronic structure of MoS_x species is modified when they are bound to the surface of Au nanoparticles.

• Based on this electronic modification, the hydrogen evolution reaction is enhanced relative to MoS₄ ligands adsorbed on a carbon surface (a non-interacting surface).

Significance:

Owing to the close integration of experimental and computational techniques, this work presents one of the most detailed structural analyses for MoS_x clusters.

(2) Indium (hydroxy)oxide films on platinum nanoparticles for CO electrooxidation