(Keynote) Transport and Mechanical Property Targets for Enabling Solid State Batteries

Abstract

Solid state batteries have become a popular topic of research in the past few years, driven by recent discoveries of solid ion conductors with high ionic conductivity. With these developments, the old problems of dendrite growth and the new problems related to interface delamination between the cathode and the solid electrolyte have become a focus of the research. While new materials are being researched that show promise, they suffer from a combination of low ionic transport properties to provide the necessary rate capability and/or from insufficient mechanical strength to prevent dendrites.Over the past several years, we have been developing mathematical methods that combine electrochemical effects (kinetics, mass transfer and ohmic) with mechanical interactions (elastic deformation, plastic deformation, and fracture) to understanding the role of material properties and operating conditions on the chemo-mechanics at the interface of both Li-metal anode and of the oxide cathode. These models have provided deep insights into the present status of polymers when used in electric vehicle applications and the targets to achieve the necessary energy and power requirements. In addition, these models have helped understand the reason for the formation of dendrites and interface delamination on the cathode/solid electrolyte interface and the targets to prevent these detrimental phenomena. Studies provide insights into the role of soft and hard materials, impact of cell pressure, and the importance of transference number on cell behavior.In this talk, we will summarize the research efforts around solid state batteries and call attention to the controlling factors that need to be the focus of future material innovations.