Abstract: Pr_1.2Sr_0.8NiO₄ (PSNO) cathode material for an intermediate-temperature solid oxide fuel cell (IT-SOFC) was synthesized by a glycine-nitrate process. The phase structure of the synthesized powders was characterized by X-ray diffraction (XRD) analysis. The thermal expansion coefficient (TEC) and the electrical conductivity of the sintered PSNO samples were measured. Electrochemical impedance spectroscopy (EIS) measurements of the PSNO materials were carried out using an electrochemical workstation. Single cells based on the Sm_0.2Ce_0.8O_1.9 (SCO) electrolyte were also assembled and tested. The results show that PSNO materials with a K₂NiF₄-type structure can be obtained by calcining the precursors at temperatures higher than 1050 °C. The sintered PSNO samples have an average TEC of about 12×10^-6 K^-1 within 200-800 °C, an electrical conductivity of 155 S·cm^-1 at 450 °C and an average conduction activation energy of 0.034 eV at 400-800 °C. Electrochemical impedance spectroscopy (EIS) shows that the area specific resistance (ASR) of the PSNO cathode on the SCO electrolyte is 0.37 Ω·cm² and the ASR of the single Ni-SCO/SCO/PSNO cell is 0.61 Ω·cm² at 700 ° C. The single Ni-SCO/SCO/ PSNO cell produces a power density of 288 mW·cm^-2 and an open circuit voltage of 0.75 V at 800 °C. Preliminary work showed that the PSNO materials may be a potential cathode material for use in IT-SOFC.

Key words: Intermediate temperature solid oxide fuel cell, PSNO cathode material, Glycinenitrate process, Thermal expansion coefficient, Electrochemical performance