“Design and discovery of solid-state ionics for energy conversion and storage”
Solid-state electrochemical devices – electrolyzers, fuel cells, and batteries – require materials that can transport ions rapidly, catalyze interfacial reactions, and withstand the chemically-induced strains inherent in operation. Design, and ultimately rapid discovery, of revolutionary solid-state-ionic materials therefore require that we uncover the relationships between point defect equilibria/kinetics, strain, and functional properties – their electro-chemo-mechanics. We pursue two approaches: 1) To uncover design principles, we systematically tailor the crystal chemistry of both bulk and thin-film ceramics, through sol-gel and pulsed laser deposition methods, respectively. We then apply a suite of in-situ characterization methods up to ~1000 °C in precisely controlled chemical potential environments to assess links between defect chemistry, crystal/micro-structure, and resulting functional behavior under dynamic conditions. 2) To discover promising compositions, we progressively filter databases with increasingly computationally expensive descriptors, and we develop high-throughput combinatorial growth and characterization methods. This talk will focus on uncovering design principles for ion-conducting, mixed ionic/electronic-conducting, and triple-conducting perovskite oxides used as electrodes and electrolytes. I will highlight: 1) lowering deleterious chemical expansivity in ceramics that “breathe,” 2) raising surface catalytic activity through chemo-mechanical actuation, and 3) boosting ionic conductivity through strain engineering. By understanding and tailoring electro-chemo-mechanical coupling through the lens of defect chemistry, we are able to develop new electrodes and electrolytes that are more durable and efficient.
