First Principles Assessment of Perovskite Dopants for Proton Conductors with Chemical Stability and High Conductivity

Perovskite-type oxides are one useful approach for proton conduction. A longstanding question in development of electrolytes has been to find the dopants that give high proton conductivity coupled with good chemical stability. We used first-principles calculations to predict the chemical stability with respect to carbonate formation and proton conductivity in doped BaZrO₃.

We use efficient methods to examine a wide range of possible dopants. In specific, we present results for BaZrO3 doped with Y, In, Ga, Sc, Nd, Al, Tl, Sm, Dy, La, Pm, Er, and Ho. These calculations identify the doped BaZrO₃ that are already known to have favorable properties, but also identify as promising a number of materials that have not been examined previously. We investigated the physical origins of the trends in chemical stability and proton mobility among different dopants. Our data allows us to consider several possible physical descriptors for characterizing doped perovskites as proton conductors.