Gas diffusion electrode with reduced diffusing capacity for water and polymer electrolyte membrane fuel cells
First Claim
Patent Images
1. A gas diffusion electrode for a polymer electrolyte membrane fuel cell to be operated with a burnable gas and an oxygen-containing gas as oxidizing agent, comprising:
- an anode electrode;
a cathode electrode; and
a polymer electrolyte membrane disposed between the anode electrode and the cathode electrode, wherein at least one electrode selected from the group consisting of the anode electrode and the cathode electrode function as the gas diffusion electrode, wherein the gas diffusion electrode has an effective diffusion constant for water, and wherein the gas diffusion electrode is filled, in at least a partial region thereof, with a filling material which reduces the effective diffusion constant of the gas diffusion electrode for water, which filling material is present in such an amount that, during a phase of continuous operation of the fuel cell under constant conditions, sufficient moisture of the polymer electrolyte membrane is maintained without adding water from outside the fuel cell for humidification of the polymer electrolyte membrane.
2 Assignments
0 Petitions
Accused Products
Abstract
Gas diffusion electrodes (1) for polymer electrolyte membrane fuel cells are modified such that the diffusion of water therein is inhibited in comparison with un-modified electrodes. Polymer electrolyte membrane fuel cells with the modified gas diffusion electrodes can be operated, with on the average unchanged operating conditions, without addition of water, since the gas diffusion electrodes do not allow more water to escape than that formed during the reaction of burnable gas and oxidizing agent, and guarantee sufficient membrane moisture.
-
Citations
38 Claims
-
1. A gas diffusion electrode for a polymer electrolyte membrane fuel cell to be operated with a burnable gas and an oxygen-containing gas as oxidizing agent, comprising:
-
an anode electrode;
a cathode electrode; and
a polymer electrolyte membrane disposed between the anode electrode and the cathode electrode, wherein at least one electrode selected from the group consisting of the anode electrode and the cathode electrode function as the gas diffusion electrode, wherein the gas diffusion electrode has an effective diffusion constant for water, and wherein the gas diffusion electrode is filled, in at least a partial region thereof, with a filling material which reduces the effective diffusion constant of the gas diffusion electrode for water, which filling material is present in such an amount that, during a phase of continuous operation of the fuel cell under constant conditions, sufficient moisture of the polymer electrolyte membrane is maintained without adding water from outside the fuel cell for humidification of the polymer electrolyte membrane. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
an anode electrode;
a cathode electrode; and
a polymer electrolyte membrane disposed between the anode electrode and the cathode electrode, wherein at least one electrode selected from the group consisting of the anode electrode and the cathode electrode functions as the gas diffusion electrode as defined in claim 1.
-
-
19. The polymer electrolyte membrane fuel cell of claim 18, wherein the gas diffusion electrode has an operating temperature ranging from 60 to 75°
- C.
-
20. The polymer electrolyte membrane fuel cell of claim 18, wherein cooling of the polymer electrolyte membrane fuel cell is effected solely by means of an air stream passed through the cathode space.
-
21. The polymer electrolyte membrane fuel cell of claim 18, wherein cooling of the polymer electrolyte membrane fuel cell is effected by water cooling.
-
22. A gas diffusion electrode for a polymer electrolyte membrane fuel cell to be operated with a burnable gas and an oxygen-containing gas as oxidizing agent, comprising:
-
an anode electrode;
a cathode electrode; and
a polymer electrolyte membrane disposed between the anode electrode and the cathode electrode, wherein at least one electrode selected from the group consisting of the anode electrode and the cathode electrode function as the gas diffusion electrode, wherein the gas diffusion electrode has an effective diffusion constant for water, wherein the gas diffusion electrode comprises a layer of at least one additional material which reduces the effective diffusion constant of the gas diffusion electrode for water such that, during a phase of continuous operation of the fuel cell under constant conditions, a sufficient moisture of the polymer electrolyte membrane is maintained without adding water from outside of the fuel cell for humidification of the polymer electrolyte membrane. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38)
an anode electrode;
a cathode electrode; and
a polymer electrolyte membrane disposed between the anode electrode and the cathode electrode, wherein at least one electrode selected from the group consisting of the anode electrode the cathode electrode functions as the gas diffusion electrode as defined in claim 22.
-
-
36. The polymer electrolyte membrane fuel cell of claim 35, wherein the gas diffusion electrode has an operating temperature ranging from 60 to 75°
- C.
-
37. The polymer electrolyte membrane fuel cell of claim 35, wherein cooling of the polymer electrolyte membrane fuel cell is effected solely by means of an air stream passed through the cathode space.
-
38. The polymer electrolyte membrane fuel cell of claim 35, wherein cooling of the polymer electrolyte membrane fuel cell is effected by water cooling.
Specification