New MIT model could help proton motion in materials at room temperature

MIT researchers have developed a new physical model that enhances the prediction of proton mobility in metal oxides, a breakthrough that could advance the development of proton-based charge carriers for renewable energy technologies such as fuel cells and electrolyzers. Unlike lithium ions, which are currently prevalent in energy storage but costly and pose safety and environmental concerns, protons are simpler and potentially safer charge carriers. However, proton conduction in metal oxides has so far only been effective at high temperatures (above 400 °C), limiting practical applications. The MIT team's model addresses this challenge by focusing on proton movement mechanisms within metal oxides, where protons hop between oxygen ions by forming and breaking covalent and hydrogen bonds. The researchers identified two key factors influencing proton conduction: hydrogen bond length and the flexibility of the oxygen ion sublattice, quantified as "O…O fluctuation," which measures changes in oxygen ion spacing due to lattice vibrations. Using a dataset of seven features affecting proton mobility, they trained an AI model to predict material