Abstract:
A water management system for a fuel cell having an anode chamber including a fuel, a cathode chamber in fluid communication with an oxidizing agent, and a proton conducting membrane electrolyte separating the chambers. The system includes a gas plenum, a first valve for controlling a first flow of a gas from the anode chamber into the gas plenum, and a second valve for controlling a second flow of the gas collected by the gas plenum into the cathode chamber. The first valve is opened allowing the first flow while the second valve is closed between the gas plenum and the cathode chamber so that effluent gas is collected in the gas plenum. When the amount of the effluent gas in the gas plenum reaches a predetermined value, the first valve is closed and the second valve is opened to allow the second flow.
Abstract:
A water management system for a fuel cell having an anode chamber including a fuel, a cathode chamber in fluid communication with an oxidizing agent, and a proton conducting membrane electrolyte separating the chambers. The system includes a gas plenum, a first valve for controlling a first flow of a gas from the anode chamber into the gas plenum, and a second valve for controlling a second flow of the gas collected by the gas plenum into the cathode chamber. The first valve is opened allowing the first flow while the second valve is closed between the gas plenum and the cathode chamber so that effluent gas is collected in the gas plenum. When the amount of the effluent gas in the gas plenum reaches a predetermined value, the first valve is closed and the second valve is opened to allow the second flow.
Abstract:
A water management system for a fuel cell having an anode chamber including a fuel, a cathode chamber in fluid communication with an oxidizing agent, and a proton conducting membrane electrolyte separating the chambers. The system includes a gas plenum, a first valve for controlling a first flow of a gas from the anode chamber into the gas plenum, and a second valve for controlling a second flow of the gas collected by the gas plenum into the cathode chamber. The first valve is opened allowing the first flow while the second valve is closed between the gas plenum and the cathode chamber so that effluent gas is collected in the gas plenum. When the amount of the effluent gas in the gas plenum reaches a predetermined value, the first valve is closed and the second valve is opened to allow the second flow.
Abstract:
Several interrelated methods are described for guaranteeing the authenticity of a fuel cartridge that will supply methanol, hydrogen, or other fuel to a fuel consuming device apparatus. Specific fuel consuming device constructions must mate with specially designed fuel cartridges to ensure that the fuel will flow properly, that the fuel supplied is of sufficient quality and composition as required, and that will be leak-proof during storage, transport, and use. Several designs that will meet all of these requirements are described below. Each of the fuel cartridge designs will result in an acceptance by the fuel consuming device if the authentication criteria are met and rejection of the cartridge if they are violated.
Abstract:
The subject matter described herein relates to a fuel cell cartridge for providing fuel to a fuel cell. Also described are fuel delivery systems, fuel cells, and related techniques.
Abstract:
A fuel cell system including an anode chamber having a fuel mixture comprising methanol and water, and a diffusion layer, a fuel source in fluid communication with the anode chamber via a conduit, a cathode chamber having a cathode and a diffusion layer, wherein the diffusion layer is in fluid communication with an oxidizer, and a proton conducting, electrical non-conducting membrane electrolyte separating the chambers and positioned substantially adjacent to said diffusion layers. The membrane includes a catalyst exposed to each of the chambers for initiating chemical reactions to produce electricity. The system also includes a first valve for automatically controlling a flow of fuel from the fuel supply cartridge, where the first valve includes a shape memory alloy.
Abstract:
A simplified direct oxidation fuel cell system is disclosed. The fuel cell is constructed in such a manner that fuel is added to the cell anode as it is consumed and water is evaporated off at cell cathode so that there is no need for recirculation of unreacted fuel at the cell anode or water at the cell cathode. In addition, carbon dioxide generated from the anodic reaction is passively vented out of the system by using a CO2 gas permeable membrane material integrated as part of the anode chamber construction. It is thus possible that, the CO2 separation from the anode fluid occurs without the recirculation of the anode fluid outside the anode chamber. In one embodiment, the simplified direct oxidation fuel cell includes a gas permeable, liquid impermeable membrane placed in close proximity to the anode to perform the carbon dioxide separation. In accordance with a further aspect of the invention, a fuel container and delivery assembly is provided, which includes separate conduits from separate containers for methanol and water and a leak-proof interface. This allows for mixing of water into the methanol solution, to allow for improved ability to adjust the concentration of methanol and water in the system. The fuel container and delivery assembly operates using simple mechanical flow and simplified geometry. This design minimizes loss of methanol and water via carryover and crossover by limiting introduction of those fluids. The passive system in which fuel is added as it is consumed and CO2 separated, both without pumping, ultimately will increase net power provided to the load due to low parasitic losses.
Abstract:
An improved fuel delivery system and fuel cell system is provided which includes a component, which delivers fuel from the fuel cartridge by connecting with a corresponding component in the anode chamber of the fuel cell. Liquid fuel is transported into the anode area via an action in which fuel is drawn through the material which may be substantially comprised of a foam-based substance. Gases, including carbon dioxide, that are produced in the anodic reaction can be removed because the foam is gas permeable. Electrons produced in the reaction are collected by a wire mesh that lies between the foam and the membrane electron assembly. The flow of fuel between the foam and the fuel cartridge and the foam and the anode can be interrupted by breaking the connection between the cartridge and the cell, or the cartridge can be pulled away from the fuel cell to break the connection between the foam components. The invention may be employed with a fuel cell stack, or with an enclosed, refillable fuel cell system. The cathode side of the fuel cell may also have a foam component to draw water away from the membrane electrode assembly while allowing oxygen to come in contact with the membrane.
Abstract:
A fuel cell diffusion layer providing a preferential path by which liquid reactants or byproducts may be supplied to or removed from a direct oxidation fuel cell is described. The modified diffusion layer will be typically on the cathode side of the fuel cell and its use is to eliminate or minimize flooding of the cathode diffusion layer area, which is a performance limiting condition in direct methanol fuel cells. In accordance with one embodiment of the invention, the diffusion layer includes a substrate that is coated with a microporous layer. A pattern may be embossed into the diffusion layer, to create preferential flow paths by which water will travel and thereby be removed from the cathode catalyst area. This avoids cathode flooding and avoids build up of potentially destructive pressure by possible cathodic water accumulation. This also provides a means for collecting cathode water for redirection In accordance with another aspect of the invention, the preferential path is established by applying a thicker microporous layer to the carbon cloth or carbon paper and drying it in such a fashion so that when it dries, the surface of the microporous layer cracks to provide the pathways.
Abstract:
A direct oxidation fuel cell which rapidly increases output power in response to demand. A conduit and valve arrangement allows neat or concentrated fuel to be introduced directly into anode flow field plate effectively bypassing the normal, time-consuming fuel flow path and eliminating the accompanying delay. A controller senses the demand for power and opens or closes the valves as appropriate. In alternative embodiments, neat or concentrated fuel is supplied directly to the anode diffusion layer or a protonically conductive membrane.