Researchers have uncovered the chemical inner-workings of an electrolyte they developed for a new generation of solid oxide fuel cells. To uncover the location of the proton-introduction reaction, the team studied extensively the hydration reaction of their scandium-substituted barium zirconate perovskite through a combination of synchrotron radiation analysis, large-scale simulations, machine learning, and thermogravimetric analysis. The new data has the potential to accelerate the development of more efficient fuel cells.