Opto-charge Microscopy (OCM): Resolving Particle Dynamics in Electrochemical Network Materials

Electrochemical materials are used in technologies ranging from rechargeable batteries and catalysts to chemical manufacturing and energy conversion. Their performance depends on how ions move through large networks of microscopic particles during operation, which is difficult to observe directly. As a result, engineers have a limited understanding of why materials charge unevenly, degrade over time, or fail prematurely. This project will create a new optical imaging method that will allow researchers to directly observe how lithium moves through battery materials during operation. The project will make characterization techniques more accessible to the research community, since it will use widely available optical equipment. The resulting knowledge and measurement capability will improve understanding of electrochemical materials and support the development of more efficient, durable, and reliable energy technologies. The project will provide interdisciplinary training for students in experimental science, computational modeling, and data analysis. Outreach to K–12 students will leverage Purdue programs using research-inspired educational activities. This project will establish opto-charge microscopy, an operando characterization framework for quantitatively mapping local lithium concentration and electrochemical heterogeneity in battery electrodes. The research will integrate operando optical imaging with first-principles calculations, finite element modeling, and quantitative image analysis to establish a physics-based relationship between optical response and lithium concentration. The project will first establish and validate the measurement framework by correlating optical signals with electronic structure calculations, electrochemical measurements, and computational modeling. It will then apply the method to investigate electrochemical dynamics, chemo-mechanical coupling, reaction pathways, and degradation processes at the single-particle level. Finally, statistical analysis of large particle populations will be used to quantify the evolution of heterogeneity and relate particle-level behavior to collective electrode performance. The resulting framework will establish a broadly applicable and experimentally accessible approach for studying electrochemical network materials, providing new capabilities for understanding and designing advanced materials for energy storage and related electrochemical technologies. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.