Researchers from China's Anhui University of Science and Technology, Huainan Normal University and University of Electronic Science and of China have developed a cooperative perovskite-based cathode design that significantly improves solid oxide fuel cell (SOFC) performance at moderate operating temperatures.
The team developed the cathode based on PrOx (Pr₆O₁₁) and a Ruddlesden-Popper (RP) perovskite (Pr₄Ni₂.₁Co₀.₉O₁₀−δ). Using a modified Pechini method, they produced a range of compositions - Pr₁.₅Ni₀.₇Co₀.₃O₄−δ (P1.5NC), Pr₁.₇Ni₀.₇Co₀.₃O₄−δ (P1.7NC), Pr₁.₉Ni₀.₇Co₀.₃O₄−δ (P1.9NC), and Pr₂.₀Ni₀.₇Co₀.₃O₄−δ (P2NC) - to fine-tune the ratio of the two phases.
By adjusting the amount of praseodymium (Pr), the researchers were able to control how much of the Pr₆O₁₁ phase formed alongside the RP perovskite. This delicate balance affects how oxygen moves through the material and how efficiently it supports the oxygen reduction reaction (ORR) that drives SOFC performance. Among all compositions, P1.9NC showed the best behavior - offering the most effective oxygen transport and the highest catalytic activity.
When tested in fuel cells, the P1.9NC cathode delivered outstanding results: low electrical resistance (0.11 Ω cm²), high power output (1029 mW cm⁻² at 800 °C), and a small activation energy (7.333 kJ mol⁻¹). It also maintained strong stability under operating conditions, making it a reliable choice for longer-term use.
Overall, this study shows how fine-tuning the Pr₆O₁₁ content in Ruddlesden-Popper perovskites can effectively adjust oxygen vacancies and electron balance - offering a new way to design more efficient, durable, and lower-temperature SOFC cathodes.
