Effect of Ni diffusion into BaZr0.1Ce0.7Y0.1Yb0.1O3−δ electrolyte during high temperature co-sintering in anode-supported solid oxide fuel cells. Issue 3 (15th February 2018)

• Record Type: Journal Article
• Authors: Shimada, Hiroyuki; Yamaguchi, Toshiaki; Sumi, Hirofumi; Yamaguchi, Yuki; Nomura, Katsuhiro; Fujishiro, Yoshinobu
• Is Part Of: Ceramics international. Volume 44:Issue 3(2018)
• Page Start: 3134
• Page End: 3140
• Publication Date: 2018-02-15
• Subjects: Solid oxide fuel cell (SOFC) -- Proton-conducting oxide -- Ni diffusion -- Co-sintering -- Conductivity -- Electron probe microanalysis (EPMA); Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2017.11.081
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Diffusion behavior of Ni during high temperature co-sintering was quantitatively investigated for anode-supported solid oxide fuel cells (SOFCs) that had BaZr0.1 Ce0.7 Y0.1 Yb0.1 O3− δ (BZCYYb) proton-conducting electrolyte and NiO-BZCYYb anode. Although diffused Ni in such SOFCs effectively acts as a sintering aid to densify the BZCYYb electrolyte layer, it often negatively affects the electrolyte conductivity. In the present study, field emission electron probe microanalysis (with wavelength dispersive X-ray spectroscopy) clearly revealed that Ni diffused into the BZCYYb electrolyte layer, and that the amount of diffused Ni increased with increasing co-sintering temperature. In particular, relatively high Ni concentration within the electrolyte layer was observed near the electrolyte/anode interface, e.g., approximately 1.5 and 2.8 wt% at co-sintering temperature of 1300 and 1400 °C, respectively. Electrochemical measurements showed that, compared with the lower co-sintering temperatures (1300–1350 °C), the highest co-sintering temperature (1400 °C) led to the highest ohmic resistance because of lower electrolyte conductivity. These results suggest that high co-sintering temperature causes excessive Ni diffusion into the BZCYYb electrolyte layer, thus degrading the intrinsic electrolyte conductivity and consequently degrading the SOFC performance.