Direct oxidation fuel cell and system operating on concentrated fuel using low oxidant stoichiometry
AssigneesMatsushita Electric Industrial Co., Ltd., The Penn State Research Foundation
InventorsChao-Yang Wang, Guoqiang Lu, Fuqiang Liu, Takashi Akiyama
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Abstract
A direct oxidation fuel cell system includes a membrane electrode assembly (MEA), a high concentration fuel and an oxidant source. Embodiments include a controller for adjusting the oxidant stoichiometric ratio or air flow to maximize the liquid water phase in the cathode exhaust and minimize the water vapor in the exhaust thereby eliminating the need for a water condenser for condensing water vapor produced and exhausted from the cathode of the MEA.
Claims18
A membrane electrode assembly for use in a direct oxidation fuel cell, the assembly comprising:
- a proton-conducting membrane electrolyte, having an anode electrode on one face and a cathode electrode on another face,
- wherein the cathode electrode includes a catalyst layer, a hydrophobic microporous layer and a hydrophobic gas diffusion layer, such that liquid water formed on the cathode can be removed, without causing substantial cathode flooding under an air stoichiometric ratio equal to or less than about 5.
A direct oxidation fuel cell system, the system comprising:
- at least one membrane electrode assembly (MEA) comprising an anode, cathode and a proton-conductive electrolyte membrane, which is sandwiched between an anode current collector plate and a cathode collector plate;
- a fuel cartridge containing high concentration fuel in fluid communication with the anode of the at least one MEA;
- an oxidant source in fluid communication with the cathode of the at least one MEA;
- and
- a controller for controlling the oxidant stoichiometric ratio to about 5 or less.
A method of operating a direct oxidation fuel system comprising at least one membrane electrode assembly (MEA), which includes an anode, cathode and a proton-conductive electrolyte membrane therebetween, the method comprising:
- providing a concentrated fuel to the anode of the MEA;
- providing an oxidant to the cathode of the MEA;
- and
- recovering liquid water directly from the cathode in sufficient quantity to supply all of the water needed for the electrochemical reaction in the anode for the entire duration of operating the direct oxidation fuel system.
Dependencies are inferred from the claim text.