Frontiers of defect, transport, and reaction theories in complex and driven solid-state ionic materials

Abstract Advances in solid-state ionic materials theory, synthesis, characterization, and simulation over the past century have enabled development of quantitative frameworks and descriptors to describe defect populations, transport, and interfacial reactions that approximate observable behavior in dilute, crystalline compositions near equilibrium. Increasing development of nondilute, disordered, or extended-defect-laden materials, and new operating conditions further from equilibrium, particularly in emerging energy, manufacturing, and information contexts, motivate development of new theoretical frameworks. This article provides an overview of computational and experimental advances in understanding defect-mediated behavior in ionic materials for batteries, fuel/electrolysis cells, sensors, thermochemical reactors, artificial synapses, ionic nanomanufacturing, and related technologies. Topics include: (1) point defects in nondilute and complex solid-solution systems, (2) point-defect populations and transport in and near extended defects, (3) defect equilibria and mobility in the excited state, (4) developing theories for ionic transport, including high-field effects and dynamic descriptors, and (5) emerging descriptors for surface reaction kinetics at intermediate-high temperatures. Graphical Abstract