Novel cobalt and strontium-free perovskite Pr0.5Ba0.5Fe1-xNixO3-δ (x=0 and 0.2) as cathode for intermediate-temperature solid oxide fuel cells

The sol-gel method was adopted to synthesize novel cobalt and strontium-free Pr 0.5 Ba 0.5 Fe 1- x Ni x O 3-δ ( x = 0 and 0.2, abbreviated as PBF and PBFN) perovskite oxides. It was aimed to discuss the influence of B-site Ni substitution on structure and electrochemical properties of Pr 0.5 Ba 0.5 FeO 3-δ . The results indicated that PBF-based oxides were both cubic perovskite structure. Ni atoms were successfully doped into the B sites of PBF, resulting in lattice shrinkage. Ni doping could enhance the oxygen reduction activity by increasing the surface oxygen content and the release of lattice oxygen to increase oxygen vacancies. At 700 °C, the cathodic polarization resistance of PBFN (0.0726 Ω·cm 2 ) was lower than PBF (0.122 Ω·cm 2 ), and the maximum power density (PPD) of PBFN (528.79 mW·cm −2 ) was higher than PBF (259.65 mW·cm −2 ). After 80 h polarization, the open-circuit voltage did not change significantly. Therefore, PBFN has the potential to be more suitable cathode material of IT-SOFCs. Graphical abstract