Electrical conductivity characteristics of Sr substituted layered perovskite cathode (SmBa0.5Sr0.5Co2O5+d) for intermediate temperature-operating solid oxide fuel cell

• Published in: Ceramics international Vol. 48; no. 11; pp. 15770 - 15779
• Main Authors: Baek, Ki Sang, Baek, Seung-Wook, Kang, Hyunil, Choi, Wonseok, Park, Jun-Young, Saxin, Stefan, Lee, Shin Ku, Kim, Jung Hyun
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2022
• Subjects: Composites; Electrical conductivity; Grain size; Sintering; Solid oxide fuel cell; Grain size; Composites; Electrical conductivity; Solid oxide fuel cell; Sintering
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2022.02.114

The high electrical conductivity of the cathode is one of the important factors for reducing the polarization resistance. For this reason, we here report the electrical conductivity characteristics of SmBa0.5Sr0.5Co2O5+δ (SBSCO) as a function of sintering temperature and current ranges. Calcined SBSCO samples were sintered at 1000, 1050, 1100, and 1150 °C. The current ranges applied in the process of measuring electrical conductivity were subdivided as 1.0A [0.05step], 0.5A [0.025step], and 0.1A [0.005step]. It was found that the sintering temperature affected the electrical conductivity in the following way: when the sintering temperature increases, an increase in the observed electrical conductivity is the result. However, as the current range decreases, it was found that the electrical conductivity would increase. The maximum and minimum conductivities of SBSCO sintered at 1150 °C were 2263S∙cm−1 at 50 °C and 382 S∙cm−1 at 900 °C with metallic behavior in air condition. When a current of 0.1A was applied to SBSCO sintered at 1150 °C, the electrical conductivity at the 800 °C was 1377.15 S/cm. It can be determined that the increase in the internal charge carrier flux of the SBSCO is associated with the decrease in the overall electrical conductivity of the Co-based metallic electrical conductivity. These results show that the high sintering temperature and low current range enable higher electrical conductivity at high operating temperature. •The maximum electrical conductivity of SBSCO sintered at 1150 °C was 2263S∙cm−1 at 50 °C and 382 S∙cm−1 at 900 °C.•The highest electrical conductivity was observed at the smallest applied current (0.1A).•The change in electrical conductivity according to the applied current can be explained by the charge carrier flux.•The SBSCO:CB cathode made of artificial porous structure shows the same electrical conductivity behavior as SBSCO cathode.