Our group works extensively with molecular simulations, thermokinetics, and experiments to provide fundamental insights and practical materials design for oxygen ion conductors. Some of our major results include:
- The discovery of the oxygen p-band descriptor, which is fast to calculate and has been shown to correlate with many oxide properties including defect formation, oxygen diffusion, species adsorption, work function, and chemical reaction rate, as summarized is recent papers covering to Op band uses.2
- Mechanistic understanding of oxygen transport and surface exchange in perovsite and related oxides, including the large impact of surface polarity on point defect concentrations3, the mechanisms controlling oxygen migration4, the magnitude and non-linear nature of the strain response of defect migration5 and formation6 energetics, the impact of these strain responses on such properties as superconductivity in thin films7, and the mechanisms of oxygen surface exchange in the fuel cell relevant (La,Sr)CoO3 family8.
- Design of novel fast oxygen conductors. We have predicted promising perovskite solid oxide fuel cell cathodes1, and with experimentalist Jian Liu (NETL) confirmed these predictions9, demonstrating that BaFe125Co0.125Zr0.75O3 is a high performing material and, when used as a composite with traditional (La,Sr)(Co,Fe)O3, can achieve some of the lowest solid oxide fuel cell cathode area specific resistances recorded to date. We are presently expanding these approaches to discover new interstitial oxygen diffusers. Multiple of the new fuel cell materials have been patented10.
1 R. Jacobs, T. Mayeshiba, J. Booske, and D. Morgan, Material Discovery and Design Principles for Stable, High Activity Perovskite Cathodes for Solid Oxide Fuel Cells, Advanced Energy Materials 8 (11) (2018).
2 R. Jacobs, J. Hwang, Y. Shao-Horn, and D. Morgan, Assessing Correlations of Perovskite Catalytic Performance with Electronic Structure Descriptors, Chemistry of Materials 31 (3), 785-797 (2019); L. Giordano, K. Akkiraju, R. Jacobs, D. Vivona, D. Morgan, and Y. Shao-Horn, Electronic Structure-Based Descriptors for Oxide Properties and Functions, Accounts of Chemical Research 55 (3), 298-308 (2022).
3 Y. L. Lee and D. Morgan, Ab Initio Defect Energetics of Perovskite (001) Surfaces for Solid Oxide Fuel Cells: A Comparative Study of Lamno3 Versus Srtio3 and Laalo3, Physical Review B 91 (19) (2015).
4 T. T. Mayeshiba and D. D. Morgan, Factors Controlling Oxygen Migration Barriers in Perovskites, Solid State Ionics 296, 71-77 (2016).
5 T. Mayeshiba and D. Morgan, Strain Effects on Oxygen Migration in Perovskites, Physical Chemistry Chemical Physics 17 (4), 2715-2721 (2015).
6 T. Mayeshiba and D. Morgan, Strain Effects on Oxygen Vacancy Formation Energy in Perovskites, Solid State Ionics 311, 105-117 (2017).
7 T. L. Meyer, R. Jacobs, D. Lee, L. Jiang, J. W. Freeland, C. Sohn, T. Egami, D. Morgan, and H. N. Lee, Strain Control of Oxygen Kinetics in the Ruddlesden-Popper Oxide La1.85sr0.15cuo4, Nature Communications 9 (2018).
8 Y. P. Cao, M. J. Gadre, A. T. Ngo, S. B. Adler, and D. D. Morgan, Factors Controlling Surface Oxygen Exchange in Oxides, Nature Communications 10 (2019).
9 R. Jacobs, J. Liu, B. T. Na, B. Guan, T. Yang, S. Lee, G. Hackett, T. Kalapos, H. Abernathy, and D. Morgan, Unconventional Highly Active and Stable Oxygen Reduction Catalysts Informed by Computational Design Strategies, Advanced Energy Materials 12 (25) (2022).
10 R. Jacobs and D. Morgan, Perovskite Compounds for Stable, High Activity Solid Oxide Fuel Cell Cathodes and Other Applications, United States Patent No. US10374262B2 (2018).