Potentiodynamic Microscopy Of Battery Materials

Abstract

This thesis presents the development and application of a custom-built electro modulation optical microscope for operando monitoring of lithium battery material charging and discharging processes, contributing to the goals of the FAIR-Battery project. In line with the FAIR principles—Findable, Accessible, Interoperable, and Reproducible—the aim was to design an affordable, scalable, and non-invasive method for real-time analysis of battery interfaces. To validate the sensitivity and functionality of the microscope, initial experiments were conducted on indium tin oxide (ITO) nano-cracks. These model systems provided a controlled platform to investigate electro-optical signal responses linked to current-induced surface phenomena. Building upon this calibration phase, the setup was extended to lithium–lithium (Li–Li) symmetric cells using a commercial EL CELL, allowing direct visualization of lithium plating and stripping dynamics under controlled electrochemical cycling. The experimental methodology combined optical monitoring with traditional electrochemical techniques, including Electrochemical Impedance Spectroscopy (EIS), multi-step amperometry, and potentiometry, alongside Fourier-based image analysis. This integrated approach enabled deeper insights into ion transport, interfacial morphology evolution, and early-stage degradation mechanisms. By bridging optical imaging and electrochemical diagnostics, this work introduces a novel, non-destructive strategy for battery health monitoring. The developed methodology advances open hardware initiatives for battery research and lays the groundwork for broader adoption of real-time optical monitoring in energy storage technologies.