Date/Time
Date(s) - 04/16/2024
3:00 pm - 4:00 pm
Location
Rhines Hall 125
Categories
Abstract
In this talk, we explore applications of nanoporous materials. We begin with fast charging energy-storage systems known as pseudocapacitors. In optimized materials, nanoscale porosity can produce a very desirable combination of electrical connectivity, electrolyte access to the interior of the material, and short solid-state ion diffusion lengths, all of which facilitate fast charge and discharge.
In parallel, the nanoscale wall dimensions can suppress intercalation-induced phase transitions, further improving kinetics. We next consider how porosity can increase stability in high-capacity alloy anode. These anodes generally show short lifetimes due to large volume changes during lithiation or sodiation, but we find that nanoscale porosity helps mitigate those volume changes. Using transmission X-ray microscopy (TXM), we can directly image changes in both individual grains, and in the pore structure itself upon cycling, allowing us to optimize materials for reversibility.
Finally, we consider the use of porous materials in multiferroic composites. Here, electricity and magnetism are coupled through strain, with a piezoelectric component straining a magnetostrictive ferromagnet. Multiferroic composites can be made using a nanoporous magnetic network that is conformally filled with a ferroelectric phase. Interestingly, we find the largest multiferroic response in materials with partly filled pores, indicating that mechanical flexibility is a key performance factor.
Bio
Sarah Tolbert, Ph.D.
Distinguished Professor
UCLA
Dr. Sarah Tolbert is a Distinguished Professor in the Departments of Chemistry and Biochemistry and Materials Science and Engineering at UCLA. Her research focuses on controlling nanometer-scale architecture in solution-processed nanomaterials to generate unique optical, electronic, magnetic, structural, and electrochemical properties. She has published over 200 scholarly research articles and has 20 patents focusing on electrochemical energy storage, organic electronics, nanomagnetics, nanoscale control of thermal conductivity, and new ultra-hard materials. She also serves as the faculty director for a program aimed at bringing nano-concepts to schools, students, and the general public throughout the greater LA area. Professor Tolbert is the recipient of a number of awards including the American Chemical Society Henry H. Storch Award in Energy Chemistry, a Fellow of the Royal Society of Chemistry, an NSF Special Creativity Award, the ACS R.A. Glen Award, and the UCLA Diversity, Equity, and Inclusion Award. She currently directs the DOE Energy Earthshot Research Center on Strain Optimization for Renewable Energy (STORE).