First Principles Computation Study and Design of δ-Bi2O3 Oxygen Ionic Conductors

Abstract

The high operating temperatures in solid oxide fuel cells (SOFC) result in high cost, reduced longevity, and decreased efficiency impeding the wide application of this technology. Lowering the temperature of SOFC requires electrolytes with high ionic conductivity at lower temperatures. Stabilized δ-Bi2O3 electrolytes have high oxygen ionic conductivity, but its activation energy of ionic conduction increases below ~600°C due to the anion lattice ordering. We performed first principles computation to study this order-disorder transition in various dopant stabilized δ-Bi2O3 electrolytes. Using first principles computation, we predicted alternative dopants to lower the transition temperature of this material for future applications in SOFCs.