The development of innovative cathode materials exhibiting high catalytic activity and good stability holds substantial significance for proton-conducting fuel cells (PCFCs). A Co-free Ba0.5Sr0.375Fe0.875Zr0.125O3-σ (BSFZ0.375) cathode material is designed and developed in this paper. Density functional theory (DFT) calculations indicate that the oxygen vacancy formation energy and hydration energy of BSFZ0.375 are both lower than those of the potential cathode Ba0.875Fe0.875Zr0.125O3-δ (BFZ). The Sr doping can reduce the oxygen dissociation barrier at the material surface according to the Partial density of states (PDOS) result. BSFZ exhibits good chemical compatibility with BaZr0.1Ce0.7Y0.1Yb0.1O3-δ (BZCYYb) electrolyte and maintains good structural stability when exposed to air for 100 h at 550 °C. At 650 °C, the polarization impedance and maximum power density of single cell with BSFZ as cathode are 0.08 Ω cm2 and 572 mW cm⁻2, which improved a lot compared to parent BFZ cathode (0.13 Ω cm2 and 228 mW cm⁻2), respectively. At 650 °C and 1.3V, the single cell with BSFZ0.375 electrode electrolyzes pure water, achieving a current density of 0.6 A cm⁻2.
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