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Novel cobalt‐free family of SrFe 1‐x Sc x O 3 ‐δ perovskite materials for cathode applications in solid oxide fuel cells
Author(s) -
Li Yan,
Larralde Ana Laura,
Cai Jiawei,
Du Shunli,
Troncoso Loreto,
FernándezDíaz María Teresa,
Alonso José Antonio
Publication year - 2020
Publication title -
international journal of energy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.808
H-Index - 95
eISSN - 1099-114X
pISSN - 0363-907X
DOI - 10.1002/er.5797
Subject(s) - materials science , cathode , electrolyte , perovskite (structure) , oxide , cobalt , solid oxide fuel cell , oxygen , fuel cells , cobalt oxide , analytical chemistry (journal) , thermogravimetric analysis , crystallography , chemical engineering , electrode , chemistry , organic chemistry , chromatography , engineering , metallurgy
Summary Perovskites of composition SrFe 1‐x Sc x O 3‐δ (x = 0.05, 0.1, 0.2) were elaborated, characterized, and tested in solid‐oxide fuel cells (SOFC) as cathode materials. Porous materials were obtained by a solid‐state route. Thermogravimetric studies showed that the oxides eliminate oxygen as temperature increases. Neutron powder diffraction (NPD) experiments unveils that, at 800°C, the crystallographic structure of SrFe 0.9 Sc 0.1 O 3‐δ contains δ = 0.51 (2) vacancies at oxygen sites, located at random in the cubic unit cell. The oxygen vacancies are essential for the oxygen diffusion, which is prerequisite for a MIEC‐type cathode. The electronic conductivity σ exhibits an insulator‐to‐metal transition at 420°C, reaching almost 200 S cm −1 for x = 0.05; σ was found to decrease as the Sc content increases. The cell performance was tested on electrolyte supported single cells, with LSGM electrolyte, fed by pure H 2 . The maximum power density reached by the Sc‐ferrite (x = 0.05) was of 340 mW cm −2 at 800°C.