Enhancing chemical stability and performance in proton-conducting solid oxide fuel cells through novel composite cathode design

Thermal and chemical compatibility between the cathode and electrolyte is crucial for the development of proton-conducting solid oxide fuel cells (H–SOFCs). To tackle this challenge, composite cathodes are often prepared by mixing traditional cathode materials with BaZr0.1Ce0.7Y0.2O3+δ (BZCY) electrolyte material. However, it should be noted that BZCY has a propensity to react with water generated during cell operation. Thus, this article presents the recent findings on performance enhancement of H–SOFCs through the utilization of a novel composite cathode, consisting of La0.6Sr0.4Co0.2Fe0.8O3+δ (LSCF) and La2-xNixCe2O7-δ (LNCOx) (x = 0.1, 0.2, 0.3, 0.4). The novel composite LSCF-LNCO0.3 cathode has shown significant improvements in the catalytic activity and durability, achieving a maximum power density of 1283 mW cm−2 at 700 °C. Density functional theoretical calculation (DFT) results reveal that the Ni doping in La2Ce2O7+δ (LCO) can effectively reduce the proton migration energy and enhance hydration ability, thereby obtaining high cathode performance. Compared traditional cathode design strategy, a novel design strategy involving the adjustment of the electrolyte component shows great potential for further advancement in cell performance.