During battery (dis)charging, lithium (de)intercalation in electrodes is usually spatially non-uniform across multiple length scales. Such phenomenon is a major impediment to battery performance and life as it causes energy under- utilization and induces over-(dis)charging, etc. While reaction heterogeneity is often attributed to mass transport limitation, this webinar will highlight the important roles of thermodynamic factors including elastic energy and phase transformations, the understanding of which is important for the development of mitigation strategies.

Through combined modelling and characterization, we elucidate how stress could destabilize the lithium (de)lithiation front in single crystalline and polycrystalline intercalation compounds, and also provide a fundamental driving force for dendrite growth on the lithium metal anode during electrodeposition. Stress relief thus offers a promising approach to improving reaction uniformity at the particle level. At the cell level, we discover that the reaction distribution within the porous electrode is strongly influenced by how the electrode’s equilibrium potential varies with the state of charge.

Two types of prototypical reaction behaviour emerge from common electrode materials with significant impact on the thick electrode performance. This finding leads to an efficient analytical model for optimizing battery configurations in place of common battery cell simulations.

Ming Tang is an associate professor in the Department of Materials Science and NanoEngineering at Rice University, US. After receiving a PhD in materials science and engineering from the Massachusetts Institute of Technology, US, he worked at Lawrence Livermore National Laboratory as a Lawrence postdoctoral fellow and then staff scientist. In 2013, Tang joined Shell Oil as a materials and corrosion engineer, and became an assistant professor at Rice University in 2015. His group is currently interested in applying combined modelling and experimental methods to understand mesoscale phenomena in energy-storage systems and use the acquired knowledge to guide microstructure design. Tang is a recipient of the 2018 Department of Energy Early Career Award.