開催日時
2026年3月4日（水）午後4:00 〜 午後5:00
講師
Nicola Helen Perry 准教授
（Department of Materials Science and Engineering, University of Illinois, Urbana-Champaign, US）
演題
“Coupled Behavior in Solid State Ionic Materials for Electrochemical Energy Applications”
Abstract
Links between dynamic chemical, mechanical, electrical, and optical properties of solid-state ionic materials can be leveraged to monitor or control behavior relevant for energy applications (fuel cells, electrolyzers, batteries, etc.). In this talk I will describe recent results that highlight two types of coupled behaviors: “photo-ionics” and “chemomechanics.”
Regarding photo-ionics, time-dependent light absorption can be used to monitor changes in defect populations, for example surface exchange reaction kinetics that govern efficiency of electrodes in fuel and electrolysis cells. In this case the relevant gas partial pressure (pO₂ or pH₂O) is stepped around a thin film electrode material and its optical relaxation over time is fit to determine a surface exchange coefficient. I will describe our recent extension of this method to evaluate oxygen exchange kinetics of combinatorial libraries and proton exchange kinetics of new triple conducting oxides. However, light absorption is also a means to control ion fluxes in materials; I will provide an example of how shining UV light onto electrode thin films can induce oxygen surface exchange and oxygen incorporation at intermediate temperatures. Understanding and leveraging such phenomena lays the foundation for a new generation of opto-ionic technologies and lies at the heart of the UIUC MRSEC Interdisciplinary Research Group on photo-ionics – the first center-wide effort in the world dedicated to this topic.
Regarding chemo-mechanics, strains/stresses accompanying defect concentration changes can be deleterious for device lifetime. To improve electrolyte and electrode stability we have been uncovering descriptors for near-zerostrain materials. Our previous work focused on crystal chemical design principles for low-strain perovskites, while our latest efforts have instead turned to the role of morphology in other crystal structures. I will discuss the effects of nanostructuring on chemical expansivity of fluorite-structured electrode candidates, where modifications to defect chemistry in the proximity of interfaces alter the macroscopic chemical strains and transport behavior. Stress/strain can also be leveraged to modify ion dynamics; one example from our work is mechano-electrochemically driven exsolution of catalytic nanoparticles on electrode surfaces to improve fuel electrode activity and device efficiency in all-fluorite cells.
座長
石原 達己 教授
（エネルギー変換科学ユニット）
言語
英語
