Coupled Ion-Electron Transfer Reactions—Dynamically-Evolving Electrodes

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_XFePO₄, oxygen evolution reaction in CoO_XH_Y, or oxygen incorporation in CeO_2-X. 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.