Revealing The Electrode and Electrolyte Microstructure in Li-Ion Batteries

The proposed academic project will help to develop a scientifically sound fundamental understanding of battery chemistries and architectures. In particular, it will focus on characterizing electrode microstructure and electrode/electrolyte interfaces; these remain areas where further study is needed to understand their influence on battery performance, long-term cycling stability, and safety. Although the proposed project aims to carry out fundamental research in the field of Li-ion batteries, the effort will aim to coordinate with and support a Navy initiative to develop and field inherently safe Li-ion battery systems based on a lithium-iron-phosphate cathode and a lithium-titanate anode. To this end, the research will be coordinated with a battery supplier company and the theoretical effort at Colorado School of Mines. In this proposed project, Northwestern University will carry out three-dimensional tomographic imaging, electrochemical testing, and analysis of the battery electrodes. Northwestern will provide the three-dimensional tomographic data on battery electrode structure on size scales from the atomic level to the electrode thickness, along with other characterization including electrochemical impedance spectroscopy using a three-electrode technique. The Northwestern group will utilize a new methodology that we recently developed to do atomic-scale 3D imaging of battery interfaces using atom probe tomography. This proposal aims to further develop this method and carry out systematic studies of interfaces in Li-ion battery materials systems of interest to the Navy. The developed methodology will also be explored as a tool for studying other electrode chemistries and alternative battery types such as solid-electrolyte batteries. These approaches are expected to yield important new insights that will help improve Li-ion battery technology.