Humidity-enhanced ceramic nearly doubles fuel cell performance: Study

A recent study by researchers at the Institute of Science, Tokyo, in collaboration with Imperial College London and Kyushu University, has demonstrated that water vapor significantly enhances the efficiency of fuel cells using the ceramic electrolyte Ba7Nb4MoO20. This hexagonal perovskite-related oxide conducts oxide ions (O²⁻) through interstitial diffusion within its crystal structure. When exposed to water vapor at 932°F (500°C), the material’s oxygen ion conductivity nearly doubles compared to dry conditions, due to the absorption of water vapor adding extra oxygen ions into structural gaps. These ions form (Nb/Mo)₂O₉ dimers that facilitate easier oxygen ion movement, thereby boosting electrical conductivity. Fuel cells typically operate at very high temperatures (up to 1,000°C), which accelerates component wear, so improving electrolyte conductivity at lower temperatures is crucial. The study’s findings, published in the Journal of Materials Chemistry A, provide new insights into how hydration affects ion transport in Ba