F-doped PrBa0.8Sr0.2Co2O5+δ−xFx (PBSCFx, x = 0, 0.025, 0.05, 0.075, 0.1) cathode powder was synthesized by the sol–gel method. X-ray diffraction results showed that all the samples doped with F exhibited a typical tetragonal perovskite structure without a heterophase. F doping can effectively reduce the thermal expansion coefficient (TEC) of the cathode materials, which decreased from 25.3699 × 10−6 K−1 of PBSC to 23.5295 × 10−6 K−1 of PBSCF0.1. The area-specific resistance (ASR) of PBSCF0.05 was 0.0207 Ω·cm2 at 800 °C, with a conductivity of 1637.27 S·cm−1 and maximum power density of 856.08 mW·cm−2. Its performance had slight decay after 100 h at 800 °C. F doping significantly improved the electrochemical performance of this cathode material for solid oxide fuel cells (SOFCs).
