Influence of sintering temperature on the properties of the screen-printed anode of the LSMO4 Ruddlesden‒Popper perovskite for intermediate-temperature solid oxide fuel cells

Abstract

This study investigates the influence of the sintering temperature on the properties of the screen-printed anode of the La0.6Sr1.4MnO4 (LSMO4) Ruddlesden‒Popper (R–P) perovskite for intermediate-temperature solid oxide fuel cell applications. LSMO4 precursor powders with a K2NiF4-type (I4/mmm space group) tetragonal structure, density of 5.823 g/cm3, and specific surface area of 2.121 m2/g were successfully synthesised through the citrate-nitrate method. Initially, the characterisation of LSMO4 anode powders was analyzed by X-ray diffraction, field emission scanning electron microscopy (FESEM), and Brunauer-Emmett-Teller analysis. Subsequently, an LSMO4 film was screen-printed onto LSGM substrates and sintered at four different temperatures: 1000 °C, 1100 °C, 1200 °C, and 1300 °C. The effect of the sintering temperature on the microstructure, electronic conductivity, and electrochemical performance of the screen-printed anode film was analyzed by FESEM, DC 4-point probe method, and electrochemical impedance spectroscopy (EIS). The different values of average surface porosities (21–35%) and anode film thickness (14–41 μm) resulting from various sintering temperatures significantly influenced the electronic conductivity and electrochemical performance of the anode films. The electrical conductivities of the anode films sintered at 1000 °C, 1100 °C, 1200 °C, and 1300 °C were found to be 1.53 S/cm, 1.95 S/cm, 3.30 S/cm, and 3.73 S/cm at 800 °C, respectively. The activation energy of anodes sintered at 1000–1300 °C was in the range of 0.61–0.72 eV. The EIS analysis showed that the LSMO4 anode film sintered at 1000 °C possessed the lowest ASR of 1.52 Ωcm2 at 800 °C under a wet gas mixture environment, 3 vol% H2O – 97 vol% (H2: N2 = 10 : 90). The findings of this study provide valuable insights into the design and optimization of R–P perovskite based anode materials.