Abstract: A simplified direct oxidation fuel cell system is provided. 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. Other embodiments of the invention include a fuel container and delivery assembly.

Abstract: Methods for conditioning the membrane electrode assembly of a direct methanol fuel cell (“DMFC”) are disclosed. In a first method, an electrical current of polarity opposite to that used in a functioning direct methanol fuel cell is passed through the anode surface of the membrane electrode assembly. In a second method, methanol is supplied to an anode surface of the membrane electrode assembly, allowed to cross over the polymer electrolyte membrane of the membrane electrode assembly to a cathode surface of the membrane electrode assembly, and an electrical current of polarity opposite to that in a functioning direct methanol fuel cell is drawn through the membrane electrode assembly, wherein methanol is oxidized at the cathode surface of the membrane electrode assembly while the catalyst on the anode surface is reduced. Surface oxides on the direct methanol fuel cell anode catalyst of the membrane electrode assembly are thereby reduced.

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.

Abstract: A conformable fuel cell is provided which includes a basic structure that provides flexibility while providing a high compression along the active surface of the fuel cell's membrane electrode assembly, which can be achieved by an injection-molded frame. A suitable fuel is delivered to the anode aspect of the fuel cell. Effective water management could also be provided by appropriate diffusion layers. The fuel cell can be contour-molded to a desired shape, or can be constructed of an array of flexibly connected individual fuel cells that overall have a curvilinear shape, or can be constructed as a pliable fuel cell that can be incorporated into an application device or an article of clothing.

Abstract: A system and method for removal or oxidative decomposition of fuel from a fuel storage container for use in a direct oxidation fuel cell and direct oxidation fuel cell system wherein the fuel permeates through a material and can be exposed to a catalyst/enzyme which oxidizes the fuel as it leaves the storage container. The system includes a fuel storage container provided with a catalyst-coated material. An airtight seal is provided over the catalyzed area, which seal is broken to allow oxygen access, and consequently the catalytic reaction. The airtight seal may be broken by simple manual methods or automatic methods on removal of the container from the fuel cell system.

Abstract: A simplified direct oxidation fuel cell system is provided. 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. Other embodiments of the invention include a fuel container and delivery assembly.

Abstract: A fuel cell system having a methanol vapor delivery component or film is provided. The component includes an evaporation pad. The evaporation pad is disposed within the fuel cell generally parallel to the anode diffusion layer, but with a vapor gap provided between the evaporation pad and the anode diffusion layer. A fuel delivery conduit having at least one injection port is provided through which liquid fuel is delivered from an associated source of highly concentrated fuel into the evaporation pad, at a controlled, adjustable rate. Multiple parallel liquid delivery points can also be provided. In order to ensure uniform delivery of fuel across the across the active area of the anode, one or more dispersion members are placed on the evaporation pad to effectively disperse the fuel laterally around each injection port.

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.

Abstract: Apparatus and methods for regulating methanol concentration in a direct methanol fuel cell system without the need for a methanol concentration sensor. One or more operating characteristics of the fuel cell, such as the potential across the load, open circuit potential, potential at the anode proximate to the end of the fuel flow path or short circuit current of the fuel cell, are used to actively control the methanol concentration.

Abstract: Oxygen-consuming zero gap chlor-alkali cell was configured to minimize peroxide formation. The cell included an ion-exchange membrane that divided the cell into an anode chamber including an anode and a cathode chamber including an oxygen gas diffusion cathode. The cathode included a single-piece of electrically conducting graphitized carbon cloth. Catalyst and polytetrafluoroethylene were attached to only one side of the cloth. When the cathode was positioned against the cation exchange membrane with the catalyst side away from the membrane, electrolysis of sodium chloride to chlorine and caustic (sodium hydroxide) proceeded with minimal peroxide formation.

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.

Abstract: Apparatus and methods for regulating methanol concentration in a direct methanol fuel cell system without the need for a methanol concentration sensor. One or more operating characteristics of the fuel cell, such as the potential across the load, open circuit potential, potential at the anode proximate to the end of the fuel flow path or short circuit current of the fuel cell, are used to actively control the methanol concentration.

Abstract: A fuel cell which provides improved performance during a cold start. Several embodiments are provided to enable the controlled introduction of fuel into the cathode of the fuel cell such that oxidation occurs, heat is released and the temperature of the fuel cell is raised. Such fuel may be introduced into the cathode directly or may be introduced into the anode and allowed to crossover an electrolytic membrane. Alternatively, the fuel may be directed through a special conduit which allows oxidation of some of the fuel as it flows through.

Abstract: A passive direct oxidation fuel cell system, which uses a high concentration fuel such as neat methanol as a direct feed to an anode aspect of the fuel cell is provided. The fuel cell includes a passive water management capability, achieved by the combined functions of controlled fuel dosing, effective bucking of liquid water from the cathode into the membrane electrolyte by a hydrophobic microporous layer well bonded the cathode catalyst and the use of a thin ionomeric membrane. These functions maintain water within the membrane and at the anode portion of the fuel cell even when only neat methanol is fed to, or contained in the anode chamber. One embodiment of the fuel cell system includes a methanol delivery film, which effects a phase change from the liquid fuel contained within a fuel reservoir to a vaporous fuel that is presented to the anode aspect of the catalyzed membrane electrolyte. Alternatively, liquid fuel delivery is controlled by a hydrophilic microporous layer.

Abstract: Passive water management techniques are provided in an air-breathing direct oxidation fuel cell system. A highly hydrophobic component with sub-micrometer wide pores is laminated to the catalyzed membrane electrolyte on the cathode side. This component blocks liquid water from traveling out of the cathode and instead causes the water to be driven through the polymer membrane electrolyte to the cell anode. The air-breathing direct oxidation fuel cell also includes a layer of cathode backing and additional cathode filter components on an exterior aspect of the cell cathode which lessen the water vapor escape rate from the cell cathode. The combination of the well laminated hydrophobic microporous layer, the thicker backing and the added filter layer, together defines a cathode structure of unique water management capacity, that enables to operate a DMFC with direct, controlled rate supply of neat (100%) methanol, without the need for any external supply or pumping of water.

Abstract: A system and method for removal or oxidative decomposition of fuel from a fuel storage container for use in a direct oxidation fuel cell and direct oxidation fuel cell system wherein the fuel permeates through a material and can be exposed to a catalyst/enzyme which oxidizes the fuel as it leaves the storage container. The system includes a fuel storage container provided with a catalyst-coated material. An airtight seal is provided over the catalyzed area, which seal is broken to allow oxygen access, and consequently the catalytic reaction. The airtight seal may be broken by simple manual methods or automatic methods on removal of the container from the fuel cell system.

Abstract: Methods for conditioning the membrane electrode assembly of a direct methanol fuel cell (“DMFC”) are disclosed. In a first method, an electrical current of polarity opposite to that used in a functioning direct methanol fuel cell is passed through the anode surface of the membrane electrode assembly. In a second method, methanol is supplied to an anode surface of the membrane electrode assembly, allowed to cross over the polymer electrolyte membrane of the membrane electrode assembly to a cathode surface of the membrane electrode assembly, and an electrical current of polarity opposite to that in a functioning direct methanol fuel cell is drawn through the membrane electrode assembly, wherein methanol is oxidized at the cathode surface of the membrane electrode assembly while the catalyst on the anode surface is reduced. Surface oxides on the direct methanol fuel cell anode catalyst of the membrane electrode assembly are thereby reduced.

Abstract: A passive fluid management component for a direct oxidation fuel cell is provided. It enables the introduction of highly concentrated methanol solutions, including neat methanol, directly into the anode, eliminating the need of mechanical modes of dosing and/or mixing a methanol/water solution to control the local concentration at the anode. The fluid management of the present invention can be based on pores formed in the component of a specific size and spacing to allow anode reactants to flow through the component towards the anode face of the membrane electrolyte of the fuel cell at a controlled rate. The pore size can be adjusted to allow the highest concentrations possible of methanol, including neat methanol, to be introduced in direct contact with the outer face of the component, said component being capable of lowering, under current, the local concentration of methanol at the anode face of the membrane electrolyte to the level required to minimize methanol loss.

Abstract: Inks are formulated for forming anode and cathode catalyst layers and applied to anode and cathode sides of a membrane for a direct methanol fuel cell. The inks comprise a Pt catalyst for the cathode and a Pt—Ru catalyst for the anode, purified water in an amount 4 to 20 times that of the catalyst by weight, and a perfluorosulfonic acid ionomer in an amount effective to provide an ionomer content in the anode and cathode surfaces of 20% to 80% by volume. The inks are prepared in a two-step process while cooling and agitating the solutions. The final solution is placed in a cooler and continuously agitated while spraying the solution over the anode or cathode surface of the membrane as determined by the catalyst content.

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.