Transported entropy in zirconia with 3 to 12 mole percent yttria

Journal Article · Fri Jan 01 04:00:00 EST 1993 · Journal of the Electrochemical Society; (United States)

DOI:https://doi.org/10.1149/1.2056110· OSTI ID:6405627

Ratkje, S K; Tomii, Yoichi ^[1]

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1. Univ. of Trondheim (Norway)

Seebeck coefficients were measured for the fuel cell (T[sub 1],p)Pt/O[sub 2](g)/YSZ/O[sub 2](g)/Pt(T[sub 2],p). The electrolyte was yttria-stabilized zirconia (YSZ) and the content of yttria in the electrolyte varied between 3 and 12 mole percent (m/o). Thus tetragonal and cubic crystal structures were investigated. Different sintering temperatures and times were used in sample preparation to produce different grain sizes in the electrolyte. The reference temperature is T[sub 1] = 1,000 C and T[sub 2] has been varied up to 1,200 C. Two different oxygen pressures were used. The transported entropy of oxygen ions calculated from the Seebeck coefficient at 1,273 K, is constant and equal to 42 [plus minus] 2 J/KF for all samples. The heat of transport q* is irrelevant to the Seebeck coefficient, as q* is related to diffusion, which does not take place. The Thomson coefficient of the material is estimated to be 18 J/KF. This result is used to compare values for the transported entropy of oxygen ions calculated from literature reports. Common expressions from thermoelectric theory are rejected on theoretical as well as experimental grounds.

• OSTI ID: 6405627
• Journal Information: Journal of the Electrochemical Society; (United States), Journal Name: Journal of the Electrochemical Society; (United States) Vol. 140:1; ISSN JESOAN; ISSN 0013-4651
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
300505* -- Fuel Cells-- Electrochemistry
Mass Transfer & Thermodynamics
CHALCOGENIDES
CRYSTAL STRUCTURE
DIRECT ENERGY CONVERTERS
ELECTROCHEMICAL CELLS
ELECTROLYTES
ENTROPY
FUEL CELLS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SAMPLE PREPARATION
SEEBECK EFFECT
SOLID ELECTROLYTE FUEL CELLS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES