A robust air electrode supported proton-conducting reversible solid oxide cells prepared by low temperature co-sintering

The developments of proton conductive reversible solid oxide cells (H-RSOCs) for medium temperature applications are greatly hampered by the limited availability of appropriate hydrogen electrode materials. Air electrode support liberates hydrogen electrode from being support body, expanding the scope of materials research and microstructure modification of hydrogen electrode. The prevalent solid oxide fuel cells air electrode La1.2Sr0.8NiO4 (LSN) is investigated as support for the reversible cell because of its excellent electrochemical properties in this research. Good chemical compatibility has been demonstrated between LSN and BaCe0.68Zr0.1Y0.1Yb0.1Cu0.02O3-δ (BCZYYC) proton conductor. Air electrode supported Ni-BCZYYC|BCZYYC|LSN-BCZYYC single cells are prepared at a quite low temperature (1200 °C) and characterized. The single cell achieved a current density of 297 mA cm-2 at 1.3 V and a maximum power density (MPD) of 120 mW cm-2 in fuel cell operational mode at 700 °C, which is encouraging to get such performance by adopting both un-modified hydrogen and oxygen electrode. The cell performance remains stable during the switching of electrolysis cell and fuel cell mode of 400 h and stays stable after 20 thermal cycles and 5 fuel gas interruptions, which makes it the most stable proton-conducting reversible cells so far, indicating that LSN-BCZYYC is the potential support for H-RSOC.