Promotion on electrochemical performance of Ba‐deficient Ba_1 − xBi_0.05Co_0.8Nb_0.15O_3 − δcathode for intermediate temperature solid oxide fuel cells

Abstract

Summary Reducing the operating temperature is the developing trend for solid oxide fuel cells. The key is to develop the cathode with high electrocatalytic activity for oxygen reduction reaction operated at reduced temperatures. Ba‐deficient Ba1 − xBi0.05Co0.8Nb0.15O3 − δ (Ba1 − xBCN, 0 ≤ x ≤ 0.10) are synthesized by solid‐state reaction method and evaluated as novel cathodes for intermediate‐temperature solid oxide fuel cells. Ba1 − xBCN is preserved to primitive cubic perovskite phase and meets the compatibility requirement with gadolinium doped ceria oxide (GDC) electrolyte at 950°C. Though the Ba deficiency distorts the cell symmetry, it improves the charge transfer steps rapidly, ascribing to the improvement of oxygen vacancy concentration. The polarization resistance of Ba0.95BCN is as low as 0.056 Ω cm2 in air at 700°C. The peak power density of the single cell with this cathode is as high as 1.41 W cm−2 at 750°C with wet H2 as fuel and air as oxidant, indicating the great potential for enhanced performance of Co‐based cathodes with A‐site deficiency.

Materials development and prospective for protonic ceramic fuel cells

“…Most of the mainstream research in SOFCs is focused on the O-SOFCs in which oxygen ion is the charge carrier in the electrolyte. [53][54][55][56][57][58][59][60][61][62][63][64] Numerous research works have been done in improving the performance, stability, and durability of O-SOFCs with remarkable progress being made, particularly in the improvement of the electrode activities of cathode materials for O-SOFC. [65][66][67][68][69][70][71] Notable research studies have also been conducted to develop and improve upon the commonly used benchmark for electrode material development (ie, BSCF) in O-SOFCs.…”