Influence of Exchange Correlation Functional on Electrochemically Relevant Properties for Protonic Ceramic Fuel Cells

Abstract

Conductivity plays a crucial role in devices for the green transition: solid-state electrolytes in all-solid-state batteries need to be ionically conductive but electronically insulating, electrodes for protonic ceramic fuel cell need to be simultaneously ionic (O2- and H+) and electron conducting. We benchmark different Density Functional Theory (DFT) methods on the accuracy of descriptors to estimate electronic and ionic conductivity as well as thermodynamic and electrochemical stability. Calculation of these using density functional theory requires relaxations, high k-point calculations and nudged elastic band calculations, which can all benefit from cheap functionals. The result of this work is to be used in a high-throughput screening for perovskite materials for protonic ceramic fuel cell cathodes.