Abstract
Gd0.2Ce0.8O3-δ (GDC) and Er0.2Bi0.8O1.5 (ESB) materials were prepared by sol-gel and co-precipitation methods. xESB (x = 1–5 wt%) was added into GDC electrolyte to investigate the effect of ESB adding on the microstructure and electrochemical properties. The results indicated that the adding of ESB improved the densification of electrolyte and generated more oxygen vacancies. The adding of ESB reduced the grain/grain boundary resistance and total resistance. 4 wt% ESB adding resulted in the highest grain boundary conductivity σgb and total conductivity σt. At 450 °C, the σgb and σt of the 4ESB-GDC were 9.23 and 3.12 times higher than GDC, respectively. At 700 °C, the SOFC (solid oxide fuel cell) supported by 4ESB-GDC electrolyte acquired a power density of 0.60 W cm?2, which was 55% higher than the SOFC supported by GDC electrolyte. During 70 h of high temperature operation, the output performance remained stable. Therefore, 4ESB-GDC should be a promising composite electrolyte candidate for IT-SOFCs (Intermediate temperature solid oxide fuel cells).
NSTL
Elsevier