MSE 298 Seminar (Zoom): Understanding the Evolution of Materials and Interfaces in Sold-State Batteries

Zoom: Meeting ID 928 7114 0676, Passcode 057979

Abstract: Solid-state batteries offer improved energy density and better safety characteristics compared to lithium-ion batteries, but interfacial evolution and chemo-mechanical degradation can limit performance. In this talk, I will present my group’s recent work using in situ and operando experiments to understand nanoscale-to-macroscale evolution of materials and interfaces in solid-state batteries. Operando X-ray tomography experiments of solid-state batteries with lithium metal anodes are shown to enable real-time quantification of interfacial contact loss between lithium metal and a solid electrolyte during cycling, which is found to cause current constriction and cell failure. Further studies reveal chemical transformations at the interface between lithium and solid electrolytes that lead to the growth of an “interphase,” which is shown to induce large stresses and to cause fracture of the solid electrolyte. Finally, reaction mechanisms in alloy-based anode materials are investigated with in situ transmission electron microscopy (TEM), and the behavior of alloy anodes within solid-state batteries is probed with in situ stack pressure measurements. Together, these findings show the controlling impact of the evolution of the structure, chemistry, and mechanics of the materials within solid-state batteries, with in situ and operando experiments being critical for understanding these processes.

Bio: Matthew McDowell is an associate professor at Georgia Tech with appointments in the Woodruff School of Mechanical Engineering and the School of Materials Science and Engineering. He received his Ph.D. from Stanford University in 2013 and was a postdoc at Caltech from 2013 until 2015. McDowell has received numerous awards, including the Presidential Early Career Award for Scientists and Engineers (PECASE), Sloan Fellowship, NSF CAREER Award, AFOSR Young Investigator Award, and the NASA Early Career Faculty Award. For more information, see https://mtmcdowell.gatech.edu.