Advancing Solid Oxide Fuel Cell Performance: Enhanced Electrochemical Properties of Pr<sub>1–<i>x</i></sub>Ca<sub><i>x</i></sub>BaFe<sub>2</sub>O<sub>5+δ</sub> Nanofiber Cathodes via Ca Doping
Xinmin Fu, X. J. Meng, Chuxiao Sun, Maobin Wei, Haipeng Jiang, Shiquan Lü, Wei‐Jiang Gong
Abstract
The double perovskite oxide PrBaFe 2 O 5+δ has great potential as a cathode material for solid oxide fuel cells (SOFCs). However, the electrochemical characteristics of Fe-based double perovskites are relatively inferior. To improve its electrochemical performance, Ca is investigated to partially replace Pr, forming Pr 1– x Ca x BaFe 2 O 5+δ (PCBF x, x = 0.0–0.3) by an electrospinning technique. The PCBF x nanofibers exhibited a crystalline structure characterized by orthorhombic symmetry and space group P 4/ mmm . Furthermore, these PCBF x nanofibers displayed exceptional chemical compatibility with the Sm 0.2 Ce 0.8 O 1.95 (SDC) electrolyte when sintered at a temperature of 900 °C for 5 h. The X-ray photoelectron spectroscopy (XPS) analysis reveals a progressive increase in the Fe 4+ concentration as the Ca doping level rises. The polarization resistances ( R p ) of the PCBF00, PCBF01, PCBF02, and PCBF03 nanofiber cathodes were 0.103, 0.079, 0.056, and 0.048 Ω cm 2 at 750 °C. In the meantime, doping Ca increases the peak power density of the single cell by 46%, from 762.80 (PCBF00) to 1114.85 (PCBF03) mW cm –2 at 750 °C. The results demonstrate that PCBF03 double perovskite nanofibers exhibit great potential as cathode materials for SOFCs.