Improving the electrical properties of Er-doped CeO<sub>2</sub> : effect of sintering aids CaO, MgO, and TiO<sub>2</sub> on conductivity

Puente-Martínez, D. E.; Díaz-Guillén, J. A.; González-García, K. A.; Montemayor, S. M.; Díaz-Guillén, J. C.; Burciaga-Díaz, O.; Bazaldúa-Medellín, M. E.; Padmasree, K. P.; Puente-Martínez, D. E.; Díaz-Guillén, J. A.; González-García, K. A.; Montemayor, S. M.; Díaz-Guillén, J. C.; Burciaga-Díaz, O.; Bazaldúa-Medellín, M. E.; Padmasree, K. P.

doi:2023.60.5.817

J. Korean Ceram. Soc. > Volume 60(5); 2023 > Article

Original Article

Journal of the Korean Ceramic Society 2023;60(5): 817-829.
doi: https://doi.org/10.1007/s43207-023-00306-4

Improving the electrical properties of Er-doped CeO₂ : effect of sintering aids CaO, MgO, and TiO₂ on conductivity

D. E. Puente-Martínez¹, J. A. Díaz-Guillén¹, K. A. González-García¹, S. M. Montemayor², J. C. Díaz-Guillén³, O. Burciaga-Díaz¹, M. E. Bazaldúa-Medellín⁴, K. P. Padmasree⁵

¹Tecnológico Nacional de México/I.T. Saltillo , 25280 Saltillo , Coahuila , Mexico
²CIQA , Enrique Reyna Hermosillo 140 , 25294 Saltillo , Coahuila , Mexico
³COMIMSA-CONACYT , Ciencia y Tecnología 790 , 25290 Saltillo , Coahuila , Mexico
⁴Universidad Autónoma de Coahuila-UAdeC, Facultad de Ingeniería , 25354 Arteaga , Coahuila , Mexico
⁵CINVESTAV Unidad Saltillo , Av. Industria Metalúrgica 1062 , 25900 Ramos Arizpe , Coahuila , Mexico

Correspondence

J. A. Díaz-Guillén ,Email: j.a.diazguillen@gmail.com ; jose.dg@saltillo.tecnm.mx

Received: January 22, 2023; Revised: April 4, 2023 Accepted: April 14, 2023. Published online: May 16, 2023.

ABSTRACT

This research reports the synthesis, characterization, and electrical properties of the systems Er_yCe_1-yO_2−δ ( y = 0.05, 0.1, and 0.15), and the eff ect of the incorporation of sintering aids (2 wt.% of CaO, MgO, and TiO₂) on the electrical properties of the composition Er_0.1Ce_0.9O_1.95, to be used as ceramic solid electrolytes in low-temperature solid oxide fuel cells (LT-SOFC). All Er_yCe_1-yO_2−δ samples were obtained by mechanochemistry (20 h of milling) and characterized by XRD. The morphology of the pure sintered compositions and with the incorporation of sintering aids (sintered at 1200 °C) was evaluated by FE-SEM. Electrical properties as a function of temperature (200–650 °C) and frequency (100 Hz–1 MHz) were evaluated by impedance spectroscopy. It reveals an increase of bulk ionic conductivity for higher contents of Er, as the number of oxygen vacancies increases. The higher value of conductivity (6.7 × 10^-3 S cm^-1 ) at 650 °C was for the composition Er_0.15Ce_0.85O _1.925, while the ionic conductivity of Er_0.1Ce_0.9O_1.95 at 650 °C increased from 2.68 × 10^-3 S cm^-1 to a maximum of 1.54 × 10^-2 S cm^-1 with the incorporation of CaO as additive. These improvements in bulk ionic conductivities can contribute to the development of more effi cient electrolytes for the LT-SOFC technology.

Key words: SOFC · Erbium-doped ceria · Ionic conductivity · Solid electrolytes · Sintering aids