NSF-BSF: Physical-Chemical Stabilization of Electrodeposition through Fundamental Interfacial Studies

Electrochemical storage systems (batteries) are ubiquitous, found in everything from commercial electronics to electric vehicles. In batteries, physical-chemical processes drive complex, coupled phenomena at the interfaces, such as electrodeposition. Electrodeposition is the deposition of metallic ions (dissolved in an electrolyte) onto an electrically conductive surface (the electrode) in the presence of an electric field. Unstable (i.e. non-uniform) electrodeposition on the electrodes of batteries leads to performance degradation and failure. This is one of the main challenges limiting next generation batteries, which hold potential for longer range electric vehicle and grid scale energy storage for renewable energy. In this project, the investigators will use an integrated computational-experimental approach to study the complex coupling of physical-chemical processes in the interface region during electrodeposition that lead to unstable deposition. The team will then use that knowledge to define regions of physical-chemical stabilization (or destabilization) of electrodeposition. This research will lay the foundation for engineering more stable batteries with longer lifetimes and higher capacities. This project is a collaboration between researchers in the United States and Israel and will provide opportunities for students to not only learn about state-of-the-art research but also to interact with and learn about different cultures. The project will train graduate students in both the United States at Boston University and in Israel at The Hebrew University of Jerusalem, and will engage k-12 students through outreach activities in both countries. Unstable electrodeposition is caused by heterogeneities, including non-uniform transport, reactivity, stresses, etc., and leads to performance loss and failure. While ideally development of homogeneous materials/interfaces/systems would solve these issues, it is impossible to fabricate perfect systems. In this project, the investigators will use an integrated computational-experimental approach to study the complex coupling of physical-chemical processes in the interface region during electrodeposition that lead to unstable deposition. The team will then use that knowledge to define regions of physical-chemical stabilization (or destabilization) of electrodeposition. Using computational and experimental model systems we will investigate the effects of both physical and chemical properties on electrodeposition for several metal systems (i.e. silver, copper, zinc, etc.) with the goal of developing a holistic understanding of the driving forces for stable electrodeposition that will lead to the mapping of electrodeposition stabilization and destabilization regimes. This project will test the hypothesis that the location and rate of electrodeposition on the electrode surface can be controlled by tuning the physical-chemical properties of the material system. To accomplish the research objectives a meso-scale computational model of the interfacial region will be coupled with controlled experimental investigations of electrodeposition. Controlled experimental studies of the electrode interface will provide data for parameterization, and validation of the model; while the computational models will guide experimental studies and provide further insight into the fundamental physical phenomena that lead to observed experimental behavior. By integrating the experimental and computational research, the project will develop a fundamental understanding of the physical-chemical processes that drive unstable or stable electrodeposition including interfacial transport, surface features, such as engineered surface roughness, changing surface reactivity through dopants, and structured interfaces. 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.