Triple perovskite structured Nd1.5Ba1.5CoFeMnO9-δ oxygen electrode materials for highly efficient and stable reversible protonic ceramic cells

The sluggish kinetics of oxygen electrode reactions represent one of the most significant barriers to realizing effective reversible protonic ceramic cells (RPCCs) at intermediate temperatures. Maximization of oxygen ion and proton conduction characteristics through hydration of electron-conducting solid oxides is a key technology that can solve this issue. We report on the exceptional performance at the oxygen electrode in RPCCs achieved using a highly defective material with excessive oxygen nonstoichiometry, Nd1.5Ba1.5CoFeMnO9-delta (NBCFM). Use of this material enables a superior reaction rate and conductivity during oxygen electrode reactions, maximizing the concentration of protons (with a high degree of hydration) as a guest ion as well as intrinsic oxygen vacancies. The peak power densities of this NBCFM cell are quite high, and a 1.4 V electrolyzing potential is achieved by NBCFM at -2.34 A.cm(-2) at 600 degrees C. Furthermore, these NBCFM cells are stable under prolonged (960 h) continuous operation at 600 degrees C.

Automated summary

The use of highly defective material NBCFM in RPCCs' oxygen electrode achieves exceptional performance with high peak power densities and stability, helping to maximize the concentration of protons and oxygen vacancies.