Hume-Rothery Symposium on Connecting Macroscopic Materials Properties to Their Underlying Electronic Structure: The Role of Theory, Computation, and Experiment: Alloy Theory II: Quantum, Electronic and Atomistic Approaches to Materials Understanding
Sponsored by: TMS Functional Materials Division, TMS Structural Materials Division, TMS: Alloy Phases Committee
Program Organizers: Raymundo Arroyave, Texas A&M University; Wei Chen, University at Buffalo; Yong-Jie Hu, Drexel University; Tresa Pollock, University of California - Santa Barbara

Monday 2:00 PM
February 28, 2022
Room: 255A
Location: Anaheim Convention Center

2:00 PM  Invited
Leveraging First-principles Theory in the Pursuit of Novel Electrode Materials: Kristin Persson1; 1University of California, Berkeley
    Today’s Li-ion batteries have become ubiquitous in electronics – however, projections of energy storage for future transportation and a sustainable grid are resource limited by current Li-ion materials which necessitates innovation of new materials and solutions. First-principles modeling enables a powerful framework for predicting and understanding the behavior of intercalation electrode materials. In this talk, we highlight several use demonstrated cases of first-principles studies which elucidated limitations of current electrode materials and predicted novel materials based on the obtained understanding. Additionally, fist-principles calculations can be scaled across supercomputing resources which enables data-driven methodologies and empowers the community; examples including the usage of the Materials Project will be presented.

2:30 PM  Invited
Prospects of Quantum Computing for Modeling Phase Transformations in Battery Materials: Maxwell Radin1; Peter Johnson1; 1Zapata Computing
    Phase transformations play an important role in the behavior of Li-ion batteries and other electrochemical systems based on intercalation. However, due to the complex electronic structure of these materials, predicting and understanding such transformations can be challenging. Although quantum computers hold the potential to surpass the capabilities of classical materials simulation, many questions remain regarding their performance and applicability to multi-scale modeling. This presentation will review models for structural phase transitions in intercalation electrodes and present resource estimates for relevant near-term quantum algorithms. Numerical simulations show the conventional Variational Quantum Eigensolver (VQE) is found to be significantly slower than classical methods and therefore unlikely to be useful as currently formulated. However, the incorporation of classical states into a subspace expansion can significantly reduce the runtime of VQE, suggesting that such “classical boosting” may represent a pathway for delivering quantum advantage in materials simulation.

3:00 PM  Invited
From Layered Oxides to Disordered Rocksalt Cathodes: The Future of Energy Storage by Understanding the Atomistics of Li Diffusion: Gerbrand Ceder1; 1University of California-Berkeley
    Layered cathode materials are the enabler of today’s Li-ion industry. In 2000, Dr. Van der Ven discovered the basic atomistic diffusion mechanism of Li-ions in layered cathode materials and laid the basis for our current understanding of Li transport in densely packed cathode materials. I will review some of the fundamental relations between electronic structure, cation ordering, and electrochemical performance in layered Li, Na and K-compounds, and show how the insights made in layered cathode materials are leading to a completely novel class of less resource constrained energy storage materials. By applying the same basic diffusion principles, disordered rocksalt cation materials can be turned into high-energy density materials by incorporating Li-excess. These materials diffuse lithium ions through a statistical network of low-energy migration environments and have recently been shown to have very high capacity and rate performance.

3:30 PM Break

3:50 PM  Invited
Molecular-scale Structure and Dynamics of Molten Salts: Simulations and Implications for Corrosive Processes: Nick Winner1; Haley Williams1; Raluca Scarlat1; Mark Asta1; 1University of California, Berkeley
    Thermodynamic modeling of molten phases is often essential to predicting the behavior of high-temperature materials and their environmental interactions. In this talk we focus on molten mixtures of fluoride salts of interest in nuclear energy contexts. We employ ab-initio molecular dynamics simulations to study the short and medium-range structure for three different chemistries: 2KF-NaF, 2LiF-BeF2, and 3LiF-AlF3, with and without Cr solutes. The results show qualitative differences in salt structure and dynamics. While 2KF-NaF melts show short and medium range order that is highly dynamic, 2LiF-BeF2 and 3LiF-AlF3 are characterized by formation of long-lived molecular associates that organize into oligomer structures on larger length scales, consistent with thermodynamic models. It is shown that in these associate-forming systems, dissolved Cr ions can incorporate into and be solvated within this oligomer structure. Implications for corrosive processes of molten salts will be discussed.

4:20 PM  Invited
First-principles Materials Design for Mechanically-controlled Topological Magnetism: Daniil Kitchaev1; Anton Van der Ven1; 1University of California Santa Barbara
    A central component of spintronics development is the search for materials capable of hosting exotic magnetic textures, and coupling these structures to dynamic perturbations such as elastic strain. Free energy models built up from first-principles electronic structure data offer an efficient tool to derive both general design principles and the specific materials for realizing these behaviors. I will discuss recent progress in this design of tunable magnetism focusing on the search for materials capable of mechanically actuating the formation of (anti)skyrmion spin textures over wide temperature ranges. I will describe a comprehensive exploration of high-temperature antiskyrmion hosts based on the inverse Heusler structure in which we identify synthetically-accessible compositions that allow for antiskyrmion formation to be actuated mechanically. This analysis establishes the first set of rigorous design criteria for engineering thermally-robust, mechanically-controlled topological magnetism, and identifies a number of promising chemical spaces for experimentally realizing this behavior.