Enhancing Electrochemical Performance of Reversible Solid Oxide Cells with Double Element-Deficient Pr<sub>0.97</sub>Ba<sub>0.97</sub>Co<sub>1.5</sub>Fe<sub>0.5</sub>O<sub>5+δ</sub> Oxygen Electrodes
Xurui Huang, Fengyuan Yu, Ying Yang, Peng Dai, Yuan Tang, Jun Jiang, Keying Feng, Mengyun Zhang, Yunfeng Tian, Bo Chi
Abstract
Reversible solid oxide cells (RSOCs) are state-of-the-art all-solid-state energy conversion devices that operate as either solid oxide fuel cells (SOFCs) or solid oxide electrolysis cells (SOECs), with the oxygen electrode playing a critical role in both the oxygen reduction (ORR) and oxygen evolution (OER) reactions. Herein, PrBaCo 1.5 Fe 0.5 O 5+δ (PBCF) is modified via double deficiency modulation of the A-site to improve its performance as an RSOC oxygen electrode. The cation-deficient variant, Pr 0.97 Ba 0.97 Co 1.5 Fe 0.5 O 5+δ (PBCF97), exhibits a balanced oxygen vacancy concentration and ionic conductivity. RSOCs using PBCF97-Gd 0.1 Ce 0.9 O 2 (GDC) as the oxygen electrode achieve a peak power density of 1.685 W/cm 2 in SOFC mode and a current density of 2.61 A/cm 2 at an electrolytic voltage of 1.5 V in SOEC mode at 800 °C. In addition, the cell demonstrates stable reversible operation for 160 h, highlighting its potential for advanced RSOC applications.