Structure/performance relations for Ni/yttria-stabilized zirconia anodes for solid oxide fuel cells

Journal Article · Tue Feb 01 04:00:00 EST 2000 · Journal of the Electrochemical Society

DOI:https://doi.org/10.1149/1.1393220· OSTI ID:20023336

Brown, M; Primdahl, S; Mogensen, M

The relations between morphology and electrochemical performance of Ni/yttria-stabilized zirconia (YSZ) anodes are investigated. Four types of anodes are prepared on YSZ electrolyte three-electrode pellets. A fine cermet of 0.5--1 {micro}m particles, a coarse cermet of 2--3 {micro}m particles, a porous Ni-paste anode, and a Ni-felt anode. The anodes are characterized by impedance spectroscopy at open-circuit potential, and the electrode relevant part (polarization resistance, R{sub p}) of the spectra is identified and investigated. The active thickness of the fine cermet anode is demonstrated to be about 10 {micro}m and is believed to relate to the conductivity of the YSZ network. In the temperature range 850--1,000 C, R{sub p} exhibits an apparent activation energy which increases with coarseness of the anode. No significant dependence on {rho}{sub H{sub 2}} (0.01--0.97 atm) at 1,000 C is observed. A dependence on {rho}{sub H{sub 2}O} of about R{sub p} {proportional_to} {rho}{sub H{sub 2}O}{minus}1/2 is found. Physical transport limitations are suggested as possible causes for the observed anode polarization.

• Research Organization: Univ. of Waikato, Hamilton (NZ)
• OSTI ID: 20023336
• Journal Information: Journal of the Electrochemical Society, Journal Name: Journal of the Electrochemical Society Journal Issue: 2 Vol. 147; ISSN 0013-4651; ISSN JESOAN
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
36 MATERIALS SCIENCE
ANODES
MORPHOLOGY
NICKEL
PERFORMANCE
SOLID OXIDE FUEL CELLS
YTTRIUM OXIDES
ZIRCONIUM OXIDES