La0.8Sr0.2Co1-xNixO3-δ as the Efficient Triple Conductor Air Electrode for Protonic Ceramic Cells

Highly efficient mixed H+/e(-)/O2- triple conducting air electrodes are indispensable for improving the electrochemical performance of protonic ceramic fuel cells and electrolysis cells (PCFC/ECs) operating at intermediate temperatures. This study demonstrates that single perovskite-type La0.8Sr0.2Co1-xNixO3-delta families (LSCN, x = 0-0.3) are efficient H+/e(-)/O2- triple conductors due to a pronounced hydration ability at elevated temperatures with a related enthalpy of -107 kJ mol(-1). Thermogravimetry confirmed that the oxides were capable of a 0.01 mole fraction proton uptake at 600 degrees C and p(H2O) of 0.023 atm. Reversible protonic ceramic cells were fabricated using these oxides as an air electrode and exhibited promising performance with a peak power density of 0.88 W cm(-2) in fuel cell mode and an electrolysis current of 1.09 A cm(-2) at a thermal neutral voltage in electrolysis cell mode at 600 degrees C. Impedance analysis confirmed that the polarization resistance of the La0.8Sr0.2Co0.2Ni0.3O3-delta cell was 0.09 Omega cm(2) under an open circuit potential at 600 degrees C, which is much smaller than the polarization resistances reported for cells with a single or double perovskite-type triple conductor. The current results indicate that mixed H+/e(-)/O2- triple phase conducting LSCN oxides are promising air electrodes for protonic ceramic cells operating in the intermediate temperature region at approximately 600 degrees C.

Automated summary

This study demonstrates that using single perovskite-type La0.8Sr0.2Co1-xNixO3-δ oxides as air electrodes can lead to promising performance in protonic ceramic cells operating at intermediate temperatures, around 600 degrees Celsius. The oxides exhibit efficient H+/e(-)/O2- triple conducting capabilities and have the potential to reduce polarization resistance compared to cells with single or double perovskite-type triple conductors.