Pioneering fast oxygen reduction reaction kinetics in Nd2-xSr2xNiO4 cathode for low-temperature solid oxide fuel cell

The catalytic efficiency of the cathode is paramount in elevating the operational efficacy of low-temperature solid oxide fuel cells (LT-SOFCs) through expeditious facilitation of the oxygen reduction reaction (ORR). Cathode confronts formidable challenges due to oxygen reduction reaction (ORR) kinetics. This work aims to develop a high-performance cathode by doping strontium (Sr) into Nd2-xSr2xNiO4. We synthesized a series of Nd2-xSr2xNiO4 (x: 0, 0.03, 0.06, 0.1) samples with varying Sr doping levels and evaluated their electrochemical performances. Nd2-xSr2xNiO4 with optimal ratio (x: 0.06) delivers the highest peak power density of 620-338 mw cm(-2) at 550-470 degrees C among all four samples. The electrochemical impedance spectroscopy of the optimal composition revealed that Nd2-xSr2xNiO4 exhibits low electrode polarization resistance of 0.34 ohm cm(2), depicting its high catalytic performance and compatibility with the electrolyte and anode. Furthermore, XPS spectra also suggest higher surface oxygen vacancies than the other three samples, subsequently improving the conductivity and catalytic activity. Along with high power and OCVs, Nd2-xSr2xNiO4 cathode-based SOFC is persistently stable for 40 h without significant degradation. These results conclusively point to demonstrating Nd2-xSr2xNiO4 as a high-performing cathode for LT-SOFCs.