Influence of Sintering Temperature on the Structural, Morphological, and Electrochemical Properties of NiO-YSZ Anode Synthesized by the Autocombustion Route

Abstract

In this study, nickel oxide–Y2 O3-doped ZrO2 (NiO-YSZ) composite powder as an anode material was synthesized using a cost-effective combustion method for high-temperature solid oxide fuel cell (SOFC). Further, the effects of sintering temperatures (1200, 1300, and 1400◦ C) were studied for its properties in relation to the SOFC performance. The prepared and sintered NiO-YSZ materials were characterized for their surface morphology, composition, structure, and conductivity. The cubic crystalline nature of NiO and YSZ was sufficed by X-ray diffraction, and SEM images revealed an increase in the densification of microstructure by an increase in the sintering tempera-ture. EDX spectrum confirmed the presence of nickel, yttrium, and zirconia without any impurity. Conductivity measurements, under a hydrogen environment, revealed that NiO-YSZ, sintered at 1400◦ C, exhibits better conductivity compared to the samples sintered at lower temperatures. Electrochemical performance of button-cells was also evaluated and peak power density of 0.62 Wcm−2 is observed at 800◦ C. The citrate combustion method provided peak performance for cells containing anode sintered at 1200◦ C, which was previously reported at higher sintering temperatures. There-fore, the citrate combustion method is found to be a suitable route to synthesize NiO-YSZ at low sintering temperature.