La0.6PrSr0.4NiO4–Ce0.8Pr0.2O2 composite cathode for solid oxide fuel cell

• We prepared a new composite cathode La0.6PrSr0.4NiO4–Ce0.8Pr0.2O2.
• We examined the effect of Ce0.8Pr0.2O2 addition on performance of cathode.
• The composite cathode with 40wt% Ce0.8Pr0.2O2 exhibited the best performance.
• Electrochemical reaction was controlled by oxygen surface exchange or diffusion.

(1−xwt%) La0.6PrSr0.4NiO4 – (xwt%) Ce0.8Pr0.2O2 (x = 0, 10, 20, 30, 40, 50), abbreviated as LPSN-xCPO, were prepared and used as composite cathode for intermediate temperature solid oxide fuel cell (IT-SOFC). XRD result suggested that no chemical reaction occurred between LPSN and CPO after sintering at 1200 °C for 4 h. Electrical conductivity of LPSN-xCPO decreased with x. LPSN-40CPO exhibited the best performance on cathode impedance spectra under open-circuit condition. At 700 °C, Exchange current density of LPSN-40CPO and LPSN was 50.1 and 15.8 mA cm−2, respectively, and the polarization resistance RP of LPSN-40CPO was 0.22 Ω cm2, which is about one-eighth of that of LPSN. The OCV of the cell with LPSN-40CPO as cathode was about 0.78 V, and the maximum of power density was about 88 mW cm−2. LPSN-40CPO can be a promise candidate for cathode in IT-SOFC.