Heterogeneous nanograin structured NiO-YSZ anodes via a water-in-oil microemulsion route for solid oxide fuel cells

• Published in: Journal of alloys and compounds 2017-11, Vol.723, p.681-688
• Main Authors: Rath, Manasa K., Jung, Yong Min, Park, Jeong Hwa, Joh, Dong Woo, Lee, Kang Taek
• Format: Article
• Language: English
• Subjects: Anode; Crystallization; Diffraction; Electron microscopy; Grain boundaries; Maximum power density; Microemulsion; Microemulsions; Nanocomposite; Nanocomposites; Nanostructure; Nickel oxides; NiO-YSZ; Particle physics; Particulate composites; Solid oxide fuel cells; Studies; Synthesis; Thermogravimetric analysis; Transmission electron microscopy; Triple phase boundaries; Yttria-stabilized zirconia; Yttrium oxide; Zirconium; Zirconium dioxide
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2017.06.294

A unique nanostructured NiO-yttria-stabilized zirconia (YSZ) composite is synthesized in-situ via a water-in-oil microemulsion technique for the solid oxide fuel cell (SOFC) anode. Thermogravimetric analysis and X-ray diffraction confirm that as-synthesized powders are crystallized in-situ at ∼500 °C as the distinct NiO and YSZ phases without any impurities. Moreover, transmission electron microscopy analysis reveals that the as-synthesized primary particles via microemulsion are ∼40 nm in size and have a characteristic structure in which NiO and YSZ nanograins are heterogeneously distributed. The electrochemical activity of the nanostructured NiO-YSZ composite is evaluated using an YSZ supported cell with a La0.8Sr0.2MnO3-δ-YSZ (50:50 wt.%) cathode. The maximum power density of the SOFC employing the microemulsion-mediated NiO-YSZ anode is 2.2 times greater than that of the SOFC with the conventionally ball-milled nano-sized NiO-YSZ anode. The higher performance with our nanocomposite NiO-YSZ anode is primarily attributed to its heterogeneous nanograin structure, thus leading to a significant increase in triple phase boundary densities. [Display omitted] •A unique NiO-YSZ nanocomposite is engineered via W/O microemulsion.•The nanocomposite anode is in-situ crystallized as low as 500 °C.•HR-TEM analysis by FFT shows heterogeneously distributed nanograins.•The novel anode exhibits 2.2 times higher MPD than conventional one.•The performance enhancement is due to the enlarged TPB length in the anode.