Fuel cell and membrane therefore
A fuel cell includes first and second flow field plates, and an anode electrode and a cathode electrode between the flow field plates. A polymer electrolyte membrane (PEM) is arranged between the electrodes. At least one of the flow field plates influences, at least in part, an in-plane anisotropic physical condition of the PEM that varies in magnitude between a high value direction and a low value direction. The PEM has an in-plane physical property that varies in magnitude between a high value direction and a low value direction. The PEM is oriented with its high value direction substantially aligned with the high value direction of the flow field plate.
1. A fuel cell comprising:
first and second flow field plates;
a cathode electrode and an anode electrode between the first and second flow field plates; and
a polymer electrolyte membrane (PEM) between the anode electrode and the cathode electrode, at least one of the flow field plates influences, at least in part, an in-plane anisotropic physical condition of the PEM including at least one or more of stress, electrical conductivity, elongation, and heat conductivity, which varies in magnitude between a high value direction (H fuel cell ) and a low value direction (L fuel cell ), the PEM defining an in-plane physical property associated with the anisotropic physical condition that varies in magnitude between a high value direction (H PEM ) and a low value direction (L PEM ), and the PEM is oriented between the anode electrode and the cathode electrode such that the H PEM is substantially aligned with the H fuel cell .
2. The fuel cell as recited in claim 1 , wherein the in-plane anisotropic physical condition comprises a stress applied to the PEM, and the in-plane physical property is ultimate strength.
3. The fuel cell as recited in claim 1 , wherein at least one of the flow field plates includes a manifold that is elongated along a longitudinal axis, and the H PEM is substantially parallel to the longitudinal axis.
4. The fuel cell as recited in claim 1 , wherein one of the flow field plates is an air plate that includes a manifold that is elongated along a longitudinal axis, and H PEM s substantially parallel to the longitudinal axis.
5. The fuel cell as recited in claim 1 , wherein the PEM comprises an extruded layer.
6. The fuel cell as recited in claim 1 , wherein the PEM is clamped between the flow field plates such that movement of the PEM is restricted.
7. A fuel cell comprising:
a first flow field plate;
a second flow field plate;
a cathode electrode and an anode electrode positioned between the first and second flow field plates; and
a polymer electrolyte membrane (PEM) positioned between the anode electrode and the cathode electrode, at least one of the first and second flow field plates influencing, at least in part, a stress applied to the PEM that varies in magnitude between a high value direction (H fuel cell ) and a low value direction (L fuel cell ), the PEM having a strength property that varies in magnitude between a high value direction (H PEM ) and a low value direction (L PEM ), the PEM being oriented between the anode electrode and the cathode electrode such that the H PEM is substantially aligned with the H fuel cell .
8. The fuel cell of claim 7 wherein at least one of the first and the second flow field plates includes a manifold that is elongated along a longitudinal axis of the manifold, the H PEM being substantially parallel to the longitudinal axis.
9. The fuel cell of claim 7 wherein the PEM comprises an extruded layer.
10. The fuel cell of claim 7 wherein the PEM is clamped between the first and the second flow field plates such that movement of the PEM is restricted.