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Improving Grain Boundary Conductivity of Ce 0.9 Gd 0.1 O 2 − δ Electrolyte through Compositing with Carbonate or Semiconductor
Author(s) -
Zhou Xiaomi,
Xia Chen,
Wang Xunying,
Dong Wenjing,
Wang Baoyuan
Publication year - 2020
Publication title -
energy technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.91
H-Index - 44
eISSN - 2194-4296
pISSN - 2194-4288
DOI - 10.1002/ente.202000424
Subject(s) - grain boundary , materials science , ionic conductivity , electrolyte , conductivity , oxide , analytical chemistry (journal) , chemical engineering , metallurgy , electrode , microstructure , chemistry , chromatography , engineering
In the solid oxide fuel cell field, heterogeneous ion doping is a common methodology to improve the ionic conductivity of electrolytes, but overwhelming grain boundary resistance is still the main obstacle for low‐temperature applications. According to previous reports, building rapid ion transport at the grain boundary through compositing methods was considered as a proposed design for electrolytes to decrease the grain boundary resistance and obtain high ionic conductivity. Herein, Ce 0.9 Gd 0.1 O 2 − δ (GDC) is selected as the matrix material and composited with Na 2 CO 3 and NdBa 0.5 Sr 0.5 Cu 2 O 5 + δ (NBSCu) to form GDC‐Na 2 CO 3 nanocomposite and GDC‐NBSCu composite. The grain boundary conductivity ( σ b ) is delicately separated from the EIS results, demonstrating that the σ b of GDC‐NBSCu and GDC‐Na 2 CO 3 composite are both substantially higher than that of pure GDC. Therefore, the power density maximum of GDC‐NBSCu and GDC‐Na 2 CO 3 electrolyte is 726 mW cm −2 at 600 °C and 797 mW cm −2 at 575 °C, respectively. Variety of characterization reveales that the proton contributes to the enhancement of σ b in GDC‐Na 2 CO 3 , while the band energy alignment between GDC and NBSCu works as an accelerator to promote the ionic conduction for GDC‐NBSCu.