Preparation and electrochemical properties of a Sm_(2-x)Sr_xNiO_4 cathode for an IT-SOFC

摘要

Cathodic materials Sm_(2-x)Sr_xNiO_4 (0.5 ≤ x ≤ 1.0) for an IT-SOFC (intermediate temperature solid oxide fuel cell) were prepared by the glycinenitrate process and characterized by XRD, SEM, ac impedance spectroscopy and dc polarization measurements. The results showed that no reaction occurred between the Sm_(2-x)Sr_xNiO_4 electrode and the Ce_(0.9)Gd_(0.1)O_(1.9) (CGO) electrolyte at 1100℃, and the electrode formed good contact with the electrolyte after sintering at 1000℃ for 2 h. The electrochemical properties of these cathode materials were studied using impedance spectroscopy at various temperatures and oxygen partial pressures. Sm_(1.0)Sr_(1.0)NiO_4 exhibited the lowest cathodic overpotential. The area specific resistance (ASR) was 3.06 Ω cm~2 at 700℃ in air.