Title: Design principles for Electrode-Electrolyte Interfaces in Energy Conversion and Environments

Abstract: Electrification-driven processes are essential to achieving sustainable energy and a cleaner environment, including electrochemical conversion and environmental monitoring. Designing these processes requires a deep understanding of the electrode-electrolyte interface, where molecular interactions dictate energy and power density, as well as device lifetime. Challenges arise in characterizing the interface and understanding mechanisms under operando processes. In this seminar, I will describe how we understand and design electrochemical reactions, charge transfer, and electrokinetics at the electrode-electrolyte interface in Li-ion batteries, hydrogen fuel cells, and environmental biosensing. First, I developed in situ Fourier-transform infrared spectroscopy (FTIR) with Li-ion battery cycling capabilities to elucidate the formation of the electrode-electrolyte interface layer on Ni-rich positive electrodes. The dehydrogenation pathway was identified and provides design principles for stabilizing battery cycling. Next, I discuss the ion intercalation mechanism across the interface in Li-ion batteries. I developed a charge-compensated electrochemical method to demonstrate coupled ion-electron transfer, which reveals a kinetic limitation to the maximum usable capacity. I extend these approaches to hydrogen-fuel-cell reactions, where I demonstrate mechanisms and strategies by which interfacial hydrogen bonds modify electrocatalytic kinetics. Lastly, beyond electrochemical energy conversion, I apply plasmon-enhanced Raman scattering and machine learning for biological interfaces, enabling the design of an integrated electrokinetic system for label-free bacterial identification in wastewater. These studies offer insights for the rational design of materials for next-generation batteries, electrocatalysis, and biosensing systems with improved efficiency and lifetime.

Bio: Yirui (Arlene) Zhang is a Schmidt Science Fellow at Stanford University. She received her Ph.D. from Massachusetts Institute of Technology, and B.S. from Tsinghua University. Her research focuses on interfacial mechanisms in electrochemical energy storage and biosensing. She develops in situ spectroscopy, electrochemical and plasmonic methods, combined with computations and machine learning, to elucidate and tailor the interfacial charge transfer reactions and transport at the molecular scale. Her work has been recognized by the AIChE Inaugural Gamry Award for Electrochemical Fundamentals (Faculty Candidates), CAS Future Leaders in Chemistry, The Electrochemical Society (ECS) Energy Technology Division Graduate Student Award, and the Materials Research Society (MRS) Graduate Student Silver Award, etc.