Ce-doping enhanced ORR kinetics and CO2 tolerance of Nd1-xCexBaCoFeO5+δ (x = 0–0.2) cathodes for solid oxide fuel cells

Abstract

Addressing challenges in oxygen reduction efficiency and CO2 endurance is essential for advancing the electrochemical energy conversion performance of solid oxide fuel cells (SOFCs). This investigation introduces an innovative strategy by employing Ce doping to enhance the oxygen reduction kinetics and CO2 resistance of NdBaCoFeO5+δ (NBCF) cathodes. Ce doping effectively regulates the oxygen vacancy content, the ratio of Co3+/Co4+ and Fe3+/Fe4+ in NBCF, leading to substantial improvements in oxygen exchange, lattice diffusion, and charge transfer processes. Consequently, a significant enhancement in the oxygen reduction reaction catalytic activity and CO2 endurance is achieved. At 800 °C, the introduction of 10 mol% Ce doping results in a 65.3% reduction in Rp, reaching 0.024 Ω cm2. Simultaneously, the power density experiences a 50.8% enhancement, reaching 1.0 W cm−2. The current investigation presents a novel avenue towards the advancement of next-generation high-efficiency and stable cathode materials for SOFCs.