Preparation and electrochemical properties of a Sm2−xSrxNiO4 cathode for an IT-SOFC

Cathodic materials Sm2−xSrxNiO4 (0.5 ≤ x ≤ 1.0) for an IT-SOFC (intermediate temperature solid oxide fuel cell) were prepared by the glycine-nitrate process and characterized by XRD, SEM, ac impedance spectroscopy and dc polarization measurements. The results showed that no reaction occurred between the Sm2−xSrxNiO4 electrode and the Ce0.9Gd0.1O1.9 (CGO) electrolyte at 1100 °C, and the electrode formed good contact with the electrolyte after sintering at 1000 °C for 2 h. The electrochemical properties of these cathode materials were studied using impedance spectroscopy at various temperatures and oxygen partial pressures. Sm1.0Sr1.0NiO4 exhibited the lowest cathodic overpotential. The area specific resistance (ASR) was 3.06 Ω cm2 at 700 °C in air.