Abstract: In a fuel cell assembly comprising a plurality of cell each including an electrolyte layer (2), a pair of diffusion electrode layers (3, 4) interposing the electrolyte layer between them, and a pair of flow distribution plates (5) for defining passages (11) for fuel and oxidant fluids that contact the diffusion electrode layers, the fuel cells are arranged on a common plane. Therefore, the vertical dimension of the fuel cell assembly can be minimized, and a fuel cell assembly of favorable electric properties can be achieved. Each flow distribution plate is typically formed with communication passages for communicating fluid passages defined on each side of the electrolyte layer at a prescribed pattern. The communication passages and through holes communicate the fluid passages in such a manner that adjacent fuels cells have opposite polarities.

Abstract: A fuel cell contains an electrolyte sheet sandwiched between two electrodes. One or both electrode/electrolyte interfaces includes mesoscopic three-dimensional features in a prescribed pattern. The features increase the surface area-to-volume ratio of the device and can be used as integral channels for directing the flow of reactant gases to the reaction surface area, eliminating the need for channels in sealing plates surrounding the electrodes. The electrolyte can be made by micromachining techniques that allow very precise feature definition. Both selective removal and mold-filling techniques can be used. The fuel cell provides significantly enhanced volumetric power density when compared with conventional fuel cells.

Abstract: A simple, inexpensive and highly efficient fuel cell has boundary structures made of a photo-sensitive material in combination with selective patterning. Printed circuit board (PCB) fabrication techniques combine boundary structures with two and three dimensional electrical flow path. Photo-sensitive material and PCB fabrication techniques are alternately or combined utilized for making micro-channel structures or micro stitch structures for substantially reducing dead zones of the diffusion layer while keeping fluid flow resistance to a minimum. The fuel cell assembly is free of mechanical clamping elements. Adhesives that may be conductively contaminated and/or fiber-reinforced provide mechanical and eventual electrical connections, and sealing within the assembly. Mechanically supporting backing layers are pre-fabricated with a natural bend defined in combination with the backing layers' elasticity to eliminate massive support plates and assist the adhesive bonding.

Abstract: In a fuel cell assembly comprising a plurality of cell each including an electrolyte layer (2), a pair of diffusion electrode layers (3, 4) interposing the electrolyte layer between them, and a pair of flow distribution plates (5) for defining passages (10, 11) for fuel and oxidant fluids that contact the diffusion electrode layers, the fuel cells are arranged on a common plane. Therefore, the vertical dimension of the fuel cell assembly can be minimized, and a fuel cell assembly of favorable electric properties can be achieved. Each flow distribution plate is typically formed with communication passages for communicating fluid passages defined on each side of the electrolyte layer at a prescribed pattern. The communication passages and through holes communicate the fluid passages in such a manner that adjacent fuels cells have opposite polarities.

Abstract: Dislocations are fabricated into electrolyte membrane films to increase ion conductivity. Ion and/or electron irradiation causes the growth of vacancy clusters within the thin film and collapsing into Frank dislocation loops that exhibit high ion conductivity. Maximum ion conductivity is accomplished by spatially reorienting the Frank dislocation loops during a following heat-treatment of the membrane. Thereby the dislocation loops form surface-to-surface continuous dislocations along which ions may propagate between membrane surfaces with minimal activation energies. Dislocation densities in the range of 108˜1014 cm/cm3 may be fabricated with conventional irradiation techniques into ceramics such as, for example yttria stabilized zirconia and doped ceria.

Abstract: In a fuel cell comprising a tubular casing, an electrolyte layer received in the tubular casing, and a pair of gas diffusion electrodes interposing the electrolyte layer and defining a fuel gas passage and an oxidizing gas passage, respectively, each gas diffusion electrode is formed by stacking a plurality of layers of material therefor, for instance in the axial direction of the casing. Because the gas diffusion layers are formed layer by layer, components can be formed in highly fine patterns so that a highly compact tubular fuel cell can be achieved. Similarly, the dimensions of the various elements of the fuel cell can be controlled in a highly accurate manner. Also, the geometric arrangement can be changed at will in intermediate parts of each gas passage.

Abstract: In a fuel cell comprising a tubular casing, an electrolyte layer received in the tubular casing, and a pair of gas diffusion electrodes interposing the electrolyte layer and defining a fuel gas passage and an oxidizing gas passage, respectively, each gas diffusion electrode is formed by stacking a plurality of layers of material therefor, for instance in the axial direction of the casing. Because the gas diffusion layers are formed layer by layer, components can be formed in highly fine patterns so that a highly compact tubular fuel cell can be achieved. Similarly, the dimensions of the various elements of the fuel cell can be controlled in a highly accurate manner. Also, the geometric arrangement can be changed at will in intermediate parts of each gas passage.

Abstract: A fuel cell contains an electrolyte sheet sandwiched between two electrodes. One or both electrode/electrolyte interfaces includes mesoscopic three-dimensional features in a prescribed pattern. The features increase the surface area-to-volume ratio of the device and can be used as integral channels for directing the flow of reactant gases to the reaction surface area, eliminating the need for channels in sealing plates surrounding the electrodes. The electrolyte can be made by micromachining techniques that allow very precise feature definition. Both selective removal and mold-filling techniques can be used. The fuel cell provides significantly enhanced volumetric power density when compared with conventional fuel cells.