Determination of Factors Governing Degradation of Anode-Supported Solid Oxide Fuel Cells as Influenced by Current Density and Humidity

The technology of tubular solid oxide fuel cells of cylindrical geometry has advanced enough such that several demonstration units are currently being tested. This paper presents a simple analytical model for the determination of the current density as a function of axial active cell length under idealized conditions. In addition, a current density axial profile under generator conditions obtained from modeling work is used and compared to the simpler approach. The resulting current density axial profiles are then used to design current takeoff in bus bars where the losses in the power leads are minimized. The result is an optimal scenario where bus bars can be considered to be surfaces that do not significantly affect the natural current density of the solid oxide fuel cell.

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Effect of Bi-Layer Interconnector Design on the Current Density of Solid Oxide Fuel Cells

ASME 2009 7th International Conference on Fuel Cell Science, Engineering and Technology ◽

10.1115/fuelcell2009-85024 ◽

2009 ◽

Author(s):

Qiuyang Chen ◽

Jian Zhang ◽

Qiuwang Wang ◽

Min Zeng

Keyword(s):

Fuel Cells ◽

Solid Oxide Fuel Cells ◽

Current Density ◽

Porous Electrode ◽

Solid Oxide ◽

The Novel ◽

Oxide Fuel ◽

Plane Normal ◽

Three Phase ◽

Porous Anode

The concentration gradient of fuel and oxidant gas is great in the plane normal to the solid oxide fuel cells (SOFC) three-phase-boundary (TPB) layer, especially in the porous electrode. We present a novel interconnector design, termed bilayer interconnector, for SOFC. It can distribute the fuel and air gas in the plane normal to the SOFC TPB layer. In this paper, we develop a 3D model to study the current density of the SOFC with conventional and novel bi-layer interconnectors. The numerical results show that the novel SOFC design Rib1 can slightly enhance the mass transfer in the porous anode and current density. The novel SOFC design Rib2 can improve the current density significantly under low electrical conductivity of interconnector.

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The current density and temperature distributions of anode-supported flat-tube solid oxide fuel cells affected by various channel designs

International Journal of Hydrogen Energy ◽

10.1016/j.ijhydene.2011.04.168 ◽

2011 ◽

Vol 36 (16) ◽

pp. 9936-9944 ◽

Cited By ~ 10

Author(s):

Joonguen Park ◽

Joongmyeon Bae ◽

Jae-Yuk Kim

Keyword(s):

Fuel Cells ◽

Solid Oxide Fuel Cells ◽

Current Density ◽

Solid Oxide ◽

Oxide Fuel ◽

Flat Tube ◽

Temperature Distributions

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A Multiphysics Modeling Study of (Pr0.7Sr0.3)MnO3±δ∕8mol% Yttria-Stabilized Zirconia Composite Cathodes for Solid Oxide Fuel Cells

Journal of Fuel Cell Science and Technology ◽

10.1115/1.1842782 ◽

2004 ◽

Vol 2 (1) ◽

pp. 45-51 ◽

Cited By ~ 3

Author(s):

Ke An ◽

Kenneth L. Reifsnider

Keyword(s):

Fuel Cells ◽

Ionic Conductivity ◽

Solid Oxide Fuel Cells ◽

Current Density ◽

Composite Cathode ◽

Solid Oxide ◽

Yttria Stabilized Zirconia ◽

Oxide Fuel ◽

Stabilized Zirconia ◽

Before And After

Solid oxide fuel cells (SOFCs) are expected to be a future power source. Simulation analyses of SOFCs can help to understand well the interactive functions among the multiphysics phenomena in the SOFC system. A three-dimensional multiphysics finite-element model was used to simulate the performance of a half-cell SOFC with (Pr0.7Sr0.3)MnO3±δ∕8mol% yttria-stabilized zirconia (8YSZ) composite cathode on one side of the 8YSZ electrolyte before and after aging. Multiphysics phenomena in the SOFC were considered in the modeling. The current/voltage curves simulated matched the experimental data before and after aging. The average current density was found to have a linear relationship to the logarithm of the effective exchange current density. The effect of the effective ionic conductivity of the composite cathode was more apparent for small total effective ionic conductivity values than for large ones.

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