About the Seminar
The design and operation of rechargeable batteries is predicated on orchestrating flows of mass, charge, and energy across multiple interfaces. Understanding such flows requires knowledge of atomistic and mesoscale diffusion pathways and the coupling of ion transport with electron conduction. Using multiple polymorphs of V2O5 as model systems, I will discuss our efforts to develop an Ångstrom-level view of diffusion pathways. Topochemical single-crystal-to-single-crystal transformations provide an atomistic perspective of how diffusion pathways are altered by modification of V—O connectivity, pre-intercalation, and high degrees of lithiation. Recently devised multi-step synthetic schemes enable the positioning of Li-ions across four distinct interstitial sites of a V2O5 insertion host and allow for deterministic redirection of Li-ion flows through strategic positioning of transition-metal ions.
At higher length scales, scanning transmission X-ray microscopy and ptychography imaging provide a means of mapping the accumulative results of atomic scale inhomogeneities at mesoscale dimensions and further enable tracing of stress gradients across individual particles. I will discuss strategies for the mitigation of diffusion impediments and degradation mechanisms based on controlling the coupling of chemistry, geometry, and mechanics. Some of these strategies include (a) utilization of Riemannian manifolds as a geometric design principle for electrode architectures; (b) atomistic design of polymorphs with well-defined diffusion pathways that provide frustrated coordination; and (c) site-selective modification as a means of tuning lattice incommensurability between lithiated and unlithiated phases.
About the Speaker
Sarbajit Banerjee, FRSC, FInstP, is the Davidson Chair Professor of Chemistry, Professor of Materials Science and Engineering, and Chancellor EDGES Fellow at Texas A&M University. He is a graduate of St. Stephen’s College (B.Sc.) and the State University of New York at Stony Brook (Ph.D.). He was a post-doctoral research scientist at the Nanoscale Science and Engineering Center at Columbia University prior to starting his independent career at the State University of New York at Buffalo in 2007 where he founded and served as the Co-Director of the New York State Center of Excellence in Materials Informatics. At SUNY-Buffalo, he was promoted to the rank of Associate Professor in 2012. In 2014, Prof. Banerjee moved to Texas A&M University as a Professor of Chemistry and Materials Science and Engineering and was named to the Davidson Chair in 2020. Recent distinctions include a NASA Innovative Advanced Concepts Fellowship in 2021, two separate Special Creativity Extension Awards from the National Science Foundation (2020 and 2021), the O’Donnell Award from The Academy of Medicine, Engineering, and Science of Texas (2021), and the 2021 Stanley C. Israel Southwest Regional Award for Advancing Diversity in the Chemical Sciences from the American Chemical Society.