First principles assessment of perovskite dopants for proton conductors with chemical stability and high conductivity

A longstanding aim in the development of electrolytes has been to find dopants that give high proton conductivity coupled with good chemical stability. Perovskite-type oxides are useful materials for proton conduction. We used first-principles calculations to address this topic in doped BaZrO3 with efficient methods to examine a wide range of possible dopants (Y, In, Ga, Sc, Nd, Al, Tl, Sm, Dy, La, Pm, Er, and Ho). These calculations correctly identify the doped BaZrO3 materials that are already known to have favorable properties, but also identify a number of promising materials that have not been examined previously. We investigated the physical origins of the trends in chemical stability and proton mobility among the different dopants. Our data allows us to consider several possible physical descriptors for characterizing doped perovskites as proton conductors.