IMPRS Seminar - Tridem Talk with Tamara Milicic, Bansidhar Patel and Tanja Vidakovic-Koch

The next IMPRS Seminar will be held by Tamara Milicic, Bansidhar Patel and Tanja Vidakovic-Koch

Tandem talks at IMPRS seminars are part of the IMPRS program and an excellent opportunity for researchers to exchange current findings and challenges.

Everyone interested is invited to the talks.

Topic:

Tanja Vidakovic-Koch - The fascination of electron

Abstract: In electrochemistry, chemical changes can be efficiently tracked through the movement of electrons (current). In addition, measuring the potential provides information about the losses of electron and ion carriers in an electrochemical cell. Both current and potential measurements are crucial for the diagnosis of electrochemical systems, the understanding of reaction mechanisms, and the development of new catalysts. In some applications, these measurements are often the only experimentally observable data. However, the overlap of different information in the current/potential response limits the findings and leads to incorrect interpretations. This raises the question: Can we gain selective knowledge about the different phenomena in electrochemical devices from current and potential measurements? How can we accurately interpret electrochemical systems? In the EEC group, we investigate methods that combine linear and nonlinear frequency response with data-driven analysis to gain new insights into the fascinating world of electrochemical devices, including electrolyzers and fuel cells.

Bansidhar Patel - Enhancing Electrochemical System Analysis with Data-Driven Methods

Abstract: Despite the widespread use of frequency response analysis methods like Electrochemical Impedance Spectroscopy (EIS) in examining electrochemical systems, their effectiveness is often hindered by the inability to distinguish between the contributions of different processes. This is due to the close overlap in the time constants of these processes, complicating the interpretation and necessitating sophisticated modeling techniques.

To address this challenge, we introduce a data-driven strategy utilizing the Loewner framework (LF), which enables the precise identification of individual polarization processes through their unique time constants from frequency response measurements. Furthermore, we employed a symbolic regression (SR) technique to generate accurate and comprehensible mathematical models based on the results of the LF analysis. Our results demonstrate that this novel approach enhances the accuracy and interpretability of frequency response data, providing deeper insights into the dynamic behaviors of electrochemical systems and marking a significant leap forward in the field.

Tamara Milicic – Deconvoluting the Performance Losses of Proton Exchange Membrane Water Electrolyzer

Abstract: Proton exchange membrane water electrolyzers (PEMWEs) are considered a key technology for hydrogen production and a much-needed transition to a green economy. However, this technology still faces challenges, such as material cost, performance degradation at high current densities, and durability. To overcome these obstacles, better comprehension of the kinetic, mass transport, and ohmic loss phenomena occurring in the PEMWE is required. In this project, a nonlinear frequency response (NFR) method has been developed both theoretically and experimentally to diagnose different losses in PEMWE. In addition, in-operando neutron imaging experiments have been performed to facilitate this analysis. The synergy of these techniques yields additional insights into the ohmic, kinetic, and mass transport performance losses of the PEMWE. These insights are crucial for designing efficient electrolyzers and optimizing their operation.