Self-assembled cathode induced by polarization for high-performance solid oxide fuel cell

Abstract

The pursuit of highly reactive cathodes promotes the improvement of the electrochemical performance of solid oxide fuel cells (SOFCs), while the side reaction between the cathode and the zirconia electrolyte produces a high-resistance phase impeding interfacial ionic transport. To address this issue, we designed an unsintered composite LaCo_0.6Ni_0.4O_3−δ-Er_0.4Bi_1.6O₃ (LCN-ESB) cathode via self-assembly onto a Y₂O₃-stabilized ZrO₂ (YSZ) electrolyte under in situ current polarization to fabricate a porous cathode layer and a cathode/electrolyte interface with good contact. An area-specific resistance (ASR) of 0.205 Ω cm² and a peak power density (PPD) of 0.788 W cm⁻² can be achieved by a single cell with LCN-ESB cathode at 650 °C using hydrogen as fuel, and the cell runs stably for over 100 h without severe degradation. The oxygen reduction reaction (ORR) activity of the self-assembled LCN-ESB cathode is competitive among intermediate-temperature (IT) SOFC cathodes. This work provides more possibilities for the practical application of YSZ-based SOFCs.