High-performance LSCF-BZCY-PrO2 nanocomposite multiphase cathode for protonic ceramic fuel cells

In this study, xBaZr 0.1 Ce 0.7 Y 0.2 O 3-δ (BZCY)-PrO 2 (where x represents the ratio of BZCY to PrO 2 , x = 20, 10, 5) composite powders were synthesized via an in-situ exsolution method. These powders were then mixed with La 0.8 Sr 0.2 Co 0.2 Fe 0.8 O 3-δ (LSCF) to fabricate LSCF-xBZCY-PrO 2 nanocomposite cathodes for protonic ceramic fuel cells (PCFCs). Consequently, the cathode with x = 10 demonstrated the optimal electrochemical performance, achieving a low polarization resistance ( R p) of 0.268 Ω cm 2 and a peak power density (PPD) of 0.52 W cm −2 at 650 °C, outperforming both the LSCF-20BZCY-PrO 2 and LSCF-5BZCY-PrO 2 cathodes. These values represent a significant improvement compared to conventional LSCF-BZCY cathodes ( R p = 0.506 Ω cm 2 , PPD = 0.338 W cm −2 ). Furthermore, the LSCF-10BZCY-PrO 2 cathode demonstrated excellent short-term stability under working conditions and operated continuously for 100 h. XPS, EIS, and DRT analyses revealed that the enhanced performance is primarily attributed to the improved oxygen reduction reaction (ORR) kinetics, facilitated by the incorporation of PrO 2 elements and the formation of a nanostructured morphology. This work presents a simplified and effective strategy for developing high performance nanocomposite multiphase cathodes for PCFCs, offering valuable insights into their practical application.