Constructing highly active and durable oxygen electrode by nanoengineering for reversible protonic ceramic cell

Reversible protonic ceramic cell (R-PCC) is a cost-effective and efficient energy storage and conversion system, yet the commercialization of R-PCC is hindered by the sluggish reaction kinetics of oxygen electrodes. Here, findings that dramatically enhance the reaction activity and stability of Ba0.95La0.05Fe0.8Zn0.2O3−δ-BaZr0.1Ce0.7Y0.1Yb0.1O3−δ (BLFZ-BZCYYb) oxygen electrode by PrOx nanoparticles coating are reported. PrOx-coated BLFZ-BZCYYb electrode exhibits a 55% decrease in polarization resistance at 650 °C (compared to the bare electrode). The R-PCC with PrOx-coated electrode demonstrates an excellent performance in fuel cell (peak power density of 0.747 W cm−2@650 °C) and electrolysis (current density of 0.773 A cm−2 at 650 °C and 1.3 V) modes. Furthermore, the cell exhibits good cycling stability in dual fuel cell and electrolysis modes after 60 cycles at 650 °C. The performance improvement is ascribed to a synergistic effect of PrOx (accelerated O2 dissociation) and triple conducting BLFZ, as confirmed by electrochemical impedance spectroscopy and computations.