Event
CHBE Seminar: Dr. Paul Albertus, University of Maryland (CHBE)
Friday, December 2, 2022
11:00 a.m.
Room 2108 Chemical and Nuclear Engineering Building and Via Zoom
Patricia Lorenzana
301-405-1935
plorenza@umd.edu
Title: Electrochemical-Mechanical Coupling at Li Metal / Solid Electrolyte Interfaces and the Safety of Li Metal Solid-State Batteries
Abstract:
Using Li and Na metal with a solid electrolyte in high-energy and safe batteries for consumer applications is of great interest, but our understanding of the behavior of this interface, as well as the expected safety of high-energy cells built with Li or Na metal and a solid electrolyte, requires improvement. In this talk I will describe (1) our work in both modeling and measuring electrochemical-mechanical coupling at a Li or Na metal / solid electrolyte interface, as well as (2) modeling and experimental work on Li metal solid state battery safety.
Using Li and Na metal with a solid electrolyte in high-energy and safe batteries for consumer applications is of great interest, but our understanding of the behavior of this interface, as well as the expected safety of high-energy cells built with Li or Na metal and a solid electrolyte, requires improvement. In this talk I will describe (1) our work in both modeling and measuring electrochemical-mechanical coupling at a Li or Na metal / solid electrolyte interface, as well as (2) modeling and experimental work on Li metal solid state battery safety.
The electrochemical-mechanical coupling topic (1) will focus on the influence on the current distribution of expected mechanical loadings at a metal/solid electrolyte influence, taking into account the expected plastic deformation of the metal electrode. We find that the mechanical boundary conditions, and inclusion of plastic deformation of a metal electrode such as Na or Li, strongly influences the resulting impact on the interfacial current distribution. We also find that for expected stack pressures (<1 MPa) and interface roughness (microns), mechanical stress variations do not have a significant influence on the current distribution.
The solid-state battery topic (2) will focus on a quantitative understanding of temperature rise in Li metal solid state batteries, based on the thermochemistry of the reactions that occur upon heating due to an external source (e.g., an oven test) or an internal short. Previously reported differential scanning calorimetry experiments as well as those we collect provide heat flows vs. temperature for the reactions among cell components (e.g., Li metal, cathode powder, solid electrolyte, cathode binder and conductive additive, current collectors). This data serves as a basis for modeling temperature rise in large-format cells. We find that oxygen released from metal oxide cathodes can react with molten Li in the cell and drive significant temperature rise, and discuss methods to improve the safety of Li metal solid state batteries.
