Multiscale Modeling of Materials for Clean Energy Storage and Conversion
Open Access
- Author:
- Goff, James
- Graduate Program:
- Materials Science and Engineering
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- June 08, 2021
- Committee Members:
- Kristen Fichthorn, Minor Field Member
Susan Sinnott, Co-Chair & Dissertation Advisor
John Mauro, Major Field Member
Ismaila Dabo, Co-Chair & Dissertation Advisor
Michael Janik, Outside Unit & Field Member
John Mauro, Program Head/Chair - Keywords:
- computational
electrochemistry
materials science
energy
atomistic simulation
cluster expansion
density functional theory
molecular dynamics
Monte Carlo
alloy
catalyst
battery
surface science - Abstract:
- Cleaner energy storage and conversion materials have become increasingly important over the past few decades. The need for cleaner energy alternatives has driven the development of models of electrochemical materials systems to aid in the improvement and discovery high-performance materials. Problems central to the modeling of energy storage and conversion materials are the treatment of size and time scale disparities of the electrode and the electrochemical double layer. Though the exact nature of electrochemical double layer and corresponding material interfaces are somewhat disputed, it is generally accepted that the double layer and solvent effects cannot be neglected entirely. In this dissertation, the impact of solvent effects on material performance and durability are assessed using methods that model these effects on multiple scales. These methods include density functional theory calculations of electrochemical catalyst dissolution, calculations and simulations with classical empirical potentials, and voltage-dependent cluster expansions of ion adsorption on electrified materials surfaces. The approaches developed within enable predictions of physical and chemical phenomena on larger, more representative electrochemical interface systems than those typically accessible with first-principles methods alone. It is demonstrated that the incorporation of configurational disorder may be accounted for in electrochemical interface models, and is often needed to predict properties in interfacial electrochemical systems. Novel descriptors such as generalized chemical ordering parameters and software is developed to aid in the analysis of the complex chemical structure that occurs in interfacial materials systems. In cases, multiple models are applied across multiple scales concurrently provide connections between small and large-scale electrochemical responses. It is shown how realistic models of extended electrochemical interfaces used in conjunction with small-scale descriptors may be used to discover and improve energy storage materials such as electrochemical capacitors.