A CO2-tolerant La2NiO4+δ-coated PrBa0.5Sr0.5Co1.5Fe0.5O5+δ cathode for intermediate temperature solid oxide fuel cells

La 2 NiO 4+δ (LN)-coated PrBa 0.5 Sr 0.5 Co 1.5 Fe 0.5 O 5+δ (PBSCF) composite cathode, designated as PBSCF-LN, for the intermediate temperature solid oxide fuel cells (IT-SOFCs) is prepared by solution infiltration , and investigated comparatively with single phase PBSCF cathode in the half and full cells using Ag and/or Pt paste as the current collector. Compared with Pt, Ag current collector results in a decrease of cathode polarization resistance ( R P ) by an order of magnitude, which suggests that Ag is electrocatalytically active and not suitable for the use of studying the cathode performance of IT-SOFCs. The R P value of PBSCF-LN cathode is significantly lower than that of PBSCF cathode, no matter whether Pt or Ag current collector is used for the measurement. High power densities ranging from 0.24 to 0.94 W cm −2 at temperatures between 600 and 750 °C are achieved using a full cell with PBSCF-LN cathode. Upon exposure to a CO 2 -rich atmosphere, carbonate particles are formed on the surface of PBSCF cathode, causing irreversible degradation of electrochemical performance. In contrast, the surface of PBSCF-LN cathode remains clean, and its performance degradation due to CO 2 adsorption is recoverable.