Premium
Thermodynamic Stability of Gadolinia‐Doped Ceria Thin Film Electrolytes for Micro‐Solid Oxide Fuel Cells
Author(s) -
Rupp Jennifer L.M.,
Infortuna Anna,
Gauckler Ludwig J.
Publication year - 2007
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2007.01531.x
Subject(s) - materials science , nanocrystalline material , ionic conductivity , microcrystalline , thin film , solid oxide fuel cell , chemical engineering , microstructure , grain size , electrolyte , oxide , grain boundary , composite material , nanotechnology , metallurgy , crystallography , chemistry , electrode , engineering
Next‐generation micro‐solid oxide fuel cells for portable devices require nanocrystalline thin‐film electrolytes in order to allow fuel cell fabrication on chips at a low operation temperature and with high power outputs. In this study, nanocrystalline gadolinia‐doped ceria (Ce 0.8 Gd 0.2 O 1.9− x ) thin‐film electrolytes are fabricated and their electrical conductivity and thermodynamic stability are evaluated with respect to microstructure. Nanocrystalline gadolinia‐doped ceria thin‐film material (Ce 0.8 Gd 0.2 O 1.9− x ) exhibits a larger amount of defects due to strain in the film than state‐of‐the‐art microcrystalline bulk material. This strain in the film decreases the ionic conductivity of this ionic O 2− conductor. The thermodynamic stability of a nanocrystalline ceria solid solution with 65 nm grain size is reduced compared with microcrystalline material with 3–5 μm grain size. Nanocrystalline spray‐pyrolyzed and PLD Ce 0.8 Gd 0.2 O 1.9− x thin films with average grain sizes larger than 70 nm show predominantly ionic conductivity for temperatures lower than 700°C, which is high enough to be potentially used as electrolytes in low to intermediate‐temperature micro‐solid oxide fuel cells.