Events

Electrification-driven processes are essential to energy, environment, and even health technologies, including batteries, fuel cells, and biosensing. Designing these electrochemical and electrokinetic processes requires a deep understanding of the electrode-electrolyte interface, where molecular interactions dictate critical functionalities like energy and power density, lifetime, or multiplex sensing. Challenges arise in characterizing the interface and understanding mechanisms under operando processes. In this seminar, I will describe combining advanced characterization and computation/machine learning to understand and design electrode-electrolyte interfaces in Li-ion batteries, hydrogen fuel cells, and biosensing for health monitoring. 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. A hydrogen transfer 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 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.

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.