High performance nanostructured bismuth oxide–cobaltite as a durable oxygen electrode for reversible solid oxide cells

Abstract

The high reactivity between bismuth oxide and cobaltite oxygen electrodes is a bottleneck in developing active and reliable bismuth oxide–cobaltite composite oxygen electrodes for solid oxide cells (SOCs). Herein, a Sr-free Sm_0.95Co_0.95Pd_0.05O_3−δ (SmCPd) oxygen electrode decorated with nanoscale Er_0.4Bi_1.6O₃ (ESB) is synthesized and assembled on a barrier-layer-free Y₂O₃–ZrO₂ (YSZ) electrolyte film. The cell with the ESB decorated SmCPd composite oxygen electrode exhibits a peak power density of 1.81 W cm⁻² at 750 °C and 0.58 W cm⁻² at 650 °C. More importantly, excellent operating stability is achieved in the fuel cell mode at 600 °C for 500 h, and in electrolysis and reversible modes at 750 °C for over 200 h. The results demonstrate the feasibility of applying bismuth oxide–cobaltite composite oxygen electrodes in developing high-performance and durable SOCs.