Ballard Power Systems Corporation

Michael T Davis

David P Wilkinson

Stephen A Campbell

Juergen Stumper

Gordon J Lamont

Lynn C Erickson

Haijiang Wang

John Robert Gordon

Bien Hung Chiem

Paul Beattie

Bien H Chiem

Kelvin Keen-Ven Fong

Siyu Ye

Bruce Lin

Sheilah Neumann

Goran R Vlajnic

Paul Kozak

Sonia Geillis Wong-Cheung

Francine Berretta

Performance in solid polymer electrolyte fuel cells can be improved by varying the characteristics of the ionomer used in the electrode of a membrane electrode assembly. For instance, increasing the ionomer to catalyst ratio can allow for improved performance under drier operating conditions (e.g., when less humidified reactants or higher operating temperatures are used) or when starting up in below freezing conditions.

Membrane electrode assemblies

A fuel cell fluid distribution layer, in one embodiment, comprises perforated graphite foil. The fluid distribution layer can have one or more reactant flow field channels formed in one or both major surfaces, one or more manifold openings, conductive filler on one or both major surfaces, conductive filler at least partially filling some or all perforations and/or an electrocatalyst one or both major surfaces.

Fuel cell fluid distribution layer having integral sealing capability

Fluid diffusion layers with favorable mechanical and electrical properties are prepared for fuel cell electrodes by impregnating a porous carbonaceous web with a carbonizable polymer having pyrrolidone functionality and then carbonizing the pyrrolidone polymer. The polymer having pyrrolidone functionality is stabilized against vaporization by use of an oxidization step prior to carbonization. The fluid diffusion layers are particularly suitable for use as gas diffusion layers in solid polymer electrolyte fuel cells.

Fluid diffusion layers for fuel cells

A membrane electrode assembly for an electrochemical fuel cell includes a pair of electrodes and an ion exchange membrane interposed therebetween. At least one of the electrodes comprises a porous electrode substrate. The substrate comprises a preformed macroporous web having a through-plane resistivity of greater than 1 .OMEGA.*cm. The web contains an electrically conductive filler. A method for preparing the membrane electrode assembly includes the steps of (a) forming a porous electrode substrate for an electrochemical fuel cell by filling a preformed macroporous web, the web having a through-plane resistivity of greater than 1 .OMEGA.*cm, with an electrically conductive filler and (b) consolidating the electrode pair and ion exchange membrane to form a unitary assembly.

Electrochemical fuel cell membrane electrode assembly with porous

An electrochemical fuel cell comprises a pair of separator plates and a pair of fluid distribution layers interposed between the separator plates. At least one of the fluid distribution layers comprises a sealing region and an electrically conductive, fluid permeable active region, and a preformed sheet material extending into each of the sealing region and the active region. An ion exchange membrane is interposed between at least a portion of the fluid distribution layers, and a quantity of electrocatalyst is interposed between at least a portion of each of the fluid distribution layers and at least a portion of the membrane, thereby defining the active region. Compression of the preformed sheet material by urging of the pair of plates towards each other renders the at least one fluid distribution layer substantially fluid impermeable in a direction parallel to the major planar surfaces, in the sealing region. The performed sheet material included in the at least one fluid distribution layer thus has intrinsic sealing capability. This approach reduces or eliminates the need for separate gaskets or sealing components and integrates several functions, such as sealing, fluid distribution, and current collection, in a single layer.

Electrochemical cell with fluid distribution layer having integral

A porous electrode substrate for an electrochemical fuel cell comprises at least one preformed web having low or poor electrical conductivity. The web contains an electrically conductive filler. A method for preparing a porous electrode substrate for an electrochemical fuel cell comprises the step of filling a preformed web, the web having low or poor electrical conductivity, with an electrically conductive filler.

Porous electrode substrate for an electrochemical fuel cell

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Coquitlam, Canada

Michael T Davis