2.6.5 Specifying Cathode Properties

You can use the Cathode tab of the Fuel Cell and Electrolysis Models dialog to specify zones and properties of the current collector, the flow channel, the diffusion layer, and the catalyst layer for the cathode portion of the fuel cell.

Specifying Current Collector Properties for the Cathode

Figure 2.6.9: The Cathode Tab of the Fuel Cell and Electrolysis Models Dialog With Current Collector Selected

1.   Select the Cathode tab of the Fuel Cell and Electrolysis Models dialog.

2.   Select Current Collector under Cathode Zone Type.

3.   Select a corresponding zone from the Zone(s) list. If you are modeling a fuel cell stack, then you must pick all zones of a particular type as a group.

4.   Select a Solid Material from the corresponding drop-down list. Solid materials can be customized using the Create/Edit Materials dialog. Note that for the Electrical Conductivity, you can only choose a constant value in the Create/Edit Materials dialog. The solid electrical conductivity value is the diffusivity of the solid phase potential in the solid zones.

Specifying Flow Channel Properties for the Cathode

Figure 2.6.10: The Cathode Tab of the Fuel Cell and Electrolysis Models Dialog With Flow Channel Selected

1.   Select the Cathode tab of the Fuel Cell and Electrolysis Models dialog.

2.   Select Flow Channel under Cathode Zone Type.

3.   Select a corresponding zone from the Zone(s) list. If you are modeling a fuel cell stack, then you must pick all zones of a particular type as a group.

Specifying Porous Electrode Properties for the Cathode

Figure 2.6.11: The Cathode Tab of the Fuel Cell and Electrolysis Models Dialog With Porous Electrode Selected

1.   Select the Cathode tab of the Fuel Cell and Electrolysis Models dialog.

2.   Select Porous Electrode under Cathode Zone Type.

3.   Select a corresponding zone from the Zone(s) list. If you are modeling a fuel cell stack, then you must pick all zones of a particular type as a group.

4.   Select a Solid Material from the corresponding drop-down list. Solid materials can be customized using the Create/Edit Materials dialog. Note that for the Electrical Conductivity, you can only choose a constant value in the Create/Edit Materials dialog. The solid electrical conductivity value is the diffusivity of the solid phase potential in the solid zones.

5.   Specify a value for the Porosity.

6.   Specify a value for the Viscous Resistance.

7.   Specify a value for the Contact Angle for multiphase fuel cell calculations ( $\theta_{\rm c}$ inEquation  1.5-4).

Specifying Catalyst Layer Properties for the Cathode

Figure 2.6.12: The Cathode Tab of the Fuel Cell and Electrolysis Models Dialog With TPB Layer - Catalyst Selected

1.   Select the Cathode tab of the Fuel Cell and Electrolysis Models dialog.

2.   Select TPB Layer (Catalyst) under Cathode Zone Type.

3.   Select a corresponding zone from the Zone(s) list. If you are modeling a fuel cell stack, then you must pick all zones of a particular type as a group.

4.   Select a Solid Material from the corresponding drop-down list. Solid materials can be customized using the Create/Edit Materials dialog. Note that for the Electrical Conductivity, you can only choose a constant value in the Create/Edit Materials dialog. The solid electrical conductivity value is the diffusivity of the solid phase potential in the solid zones.

5.   Specify a value for the Porosity.

6.   Specify a value for the Viscous Resistance.

7.   Specify a value for the Surface/Volume Ratio (the specific active surface area in Equation  1.2-4).

8.   Specify a value for the Contact Angle for multiphase fuel cell calculations ( $\theta_{\rm c}$ in Equation  1.5-4).

Specifying Cell Zone Conditions for the Cathode

For each case of the cathode's current collector, diffusion layer, and catalyst layer, you assign a solid material and/or set the porosity and the viscous resistance. These settings represent setting a cell zone condition. With the Update Cell Zones option turned on (the default setting), this cell zone condition is applied to all selected zones in the Zone(s) list. If you want to set the cell zone conditions for each zone individually (using the Cell Zone Conditions task page), you should turn off the Update Cell Zones option.