(Keynote) Chemical and Mechanical Stability Issues at Electrolyte/Electrode Interfaces in Solid State Batteries

Stringent chemical and mechanical constraints apply to the interfaces in solid state batteries. They have to be (electro)chemically stable against the chosen electrode materials and applied potentials. In addition, they have to be tolerant to the various mechanical issues that occur in solid state batteries such as electrode swelling/shrinking, stress concentrations at current focusing areas etc. I will present the requirements for chemically stable interfaces between various cathode and electrolyte materials and discuss to what extent coatings can address chemical incompatibility. For the lithium anode side I will present results from modeling to understand the interplay between current density, stress, and lithium growth through the electrolyte. Our results indicate that in good conductors stress build up to the point that it fractures the electrolyte is unlikely. We also find that conductivity of the solid electrolyte plays a central role in the mechanical reliability of a solid-state battery.