Energetics of proton transfer in alkali carbonates: a first principles calculation

Abstract

Recent development of dual-phase ceramic–carbonate composite electrolytes for intermediate-temperature solid oxide fuel cells (SOFCs) has prompted a pressing question as to whether H⁺ can transfer in molten carbonates and play a role in the enhanced ionic conductivity and improved SOFC performance. In the present study, we use a first principles approach to examine the energetics of H⁺-transfer in CO₃²⁻, Li₂CO₃ crystals and (Li₂CO₃)₈ clusters. The results indicate that H⁺-transfer in solid carbonates is difficult, but very facile in a (Li₂CO₃)₈ cluster, a surrogate of molten carbonates.