William C. Chueh1
Most non-metallic electrocatalysts and battery electrodes change composition during operation. This change in the composition directly modifies the kinetics of heterogeneous reactions at the electrode/electrolyte interface, whether it is the lithium intercalation reaction in Li<sub>X</sub>FePO<sub>4</sub>, oxygen evolution reaction in CoO<sub>X</sub>H<sub>Y</sub>, or oxygen incorporation in CeO<sub>2-X</sub>. While it is possible to infer the composition of the electrode via electrochemical measurements, knowing the composition at or near the active site is challenging. In this talk, I will present on the development of operando nanoscale microscopy (specifically, X-ray and scanning probe) and spectroscopy to track the dynamic evolution of electrocatalysts and battery electrodes during operation, and how the composition of the active site modifies reaction kinetics.