Abstract: Water management is improved in solid polymer electrolyte fuel cells by employing capillary channels or wicks in the lands that separate the reactant distribution channels in the flow fields. Capillary action moves water within these micro-sized capillary channels or wicks. Appropriate designs can be used to assist in the removal of water from the cell and/or in the redistribution of water from relatively wet regions in the cell to relatively dry regions.

Abstract: An improved membrane electrode assembly (“MEA”) for an electrochemical fuel cell comprises coextensive ion exchange membrane and electrode layers and a rigid fluid impermeable integral seal comprising a sealant material impregnated into the porous electrode layers in sealing regions of the MEA. The integral seal envelops the peripheral region including the side edge of the MEA. The integral seal can circumscribe the electrochemically active area of the MEA and can also extend laterally beyond the edge of the MEA. An integral seal can also be provided around any openings, such as manifold openings, that are formed inside or outside the MEA. The seal has sealing features formed therein, such as raised ribs. Sealing features can be formed from the rigid sealant material or from resilient sealant material applied to the surface of the integral seal.

Abstract: Flow fields comprising a set of fluid distribution channels may be employed in fuel cells for purposes of distributing fluid reactants to an electrochemically active area of the fuel cell. Water management and reactant distribution may be improved by increasing pressure gradients between adjacent channels. Such pressure gradients may be increased by engineering the channels such that the resistance to reactant flow differs along the length of adjacent channels.

Abstract: A method and apparatus for cooling an electrochemical fuel cell which comprises coolant channels extending along the edge of the fuel cell, adjacent to the active area whereby the fuel cell is cooled by evaporating a liquid coolant in the coolant channels. The coolant may then be condensed and recirculated through the coolant channels. Efficient cooling of the fuel cell may be enhanced by reducing the boiling point of the coolant by reducing the pressure across the coolant channels.

Abstract: An improved flow field design for a flow field plate comprises fluid distribution channels having an average width W and separated by landings in which the channels are configured such that unsupported rectangular surfaces of length L and width W on an adjacent fluid diffusion layer have a ratio L/W less than about 3. Improved support may be obtained for instance by using sinusoidally shaped channels. Certain fluid diffusion layer embodiments offer desirable characteristics (for example, low cost, thickness) for use in fuel cells but may also be undesirably weak mechanically and consequently will benefit from improved mechanical support from adjacent flow field plates comprising the present flow field design.

Abstract: A flow field plate for a liquid feed fuel cell has a liquid reactant (for example, fuel) flow field comprising a plurality of horizontal parallel substantially straight channels formed on one major surface of the plate. The plate has another reactant (for example, oxidant) flow field on the other major surface of the plate. The liquid reactant channels may have an open width less than about 0.75 millimeter and/or a length to cross sectional area ratio between about 2180:1 to about 6200:1. A simple four-port configuration is employed for the inlets and outlets for the reactants. The liquid reactant can also serve as a coolant for the fuel cell.

Abstract: An improved flow field design for a flow field plate comprises fluid distribution channels having an average width W and separated by landings in which the channels are configured such that unsupported rectangular surfaces of length L and width W on an adjacent fluid diffusion layer have a ratio L/W less than about 3. Improved support may be obtained for instance by using sinusoidally shaped channels. Certain fluid diffusion layer embodiments offer desirable characteristics (for example, low cost, thickness) for use in fuel cells but may also be undesirably weak mechanically and consequently will benefit from improved mechanical support from adjacent flow field plates comprising the present flow field design.