Vacancy-mediated ultrafast oxide-ion conduction in excess-oxygen Sillén oxybromides.

Excess-oxygen Sillén oxybromides exhibit a vacancy-mediated oxide-ion conductivity of 0.01 S cm⁻¹ at 233°C, surpassing many leading conductors in dry atmospheres.

• Why it matters: High-performance electrolytes for low-temperature solid oxide fuel cells are needed to reduce costs, but current materials often fall short in conductivity or stability, creating a critical gap.
• What they did: The study synthesized Bi 1.9 Te 0.1 LaO 4.05 Br and used ab initio molecular dynamics, density functional theory, and neutron diffraction to analyze its structure and ion transport mechanisms.
• The result: Findings suggest that vacancy-mediated oxide-ion migration in excess-oxygen Bi-containing Sillén oxyhalides can inform the design of advanced oxide-ion conductors with high conductivity and stability.