Ballard Power Systems Corporation

Bien Hung Chiem

David P Wilkinson

Joerg Zimmermann

Joy A Roberts

Jean St-Pierre

Michael T Davis

Haijiang Wang

John Robert Gordon

Lynn C Erickson

J&uuml;rgen Stumper

Kelvin Keen-Ven Fong

Paul Beattie

Sheilah Neumann

Paul Kozak

Sonia Geillis Wong-Cheung

A method of controlling the temperature within an electrochemical fuel cell stack comprises introducing a reactant fluid stream comprising both a heat transfer liquid and a reactant into a fuel cell assembly such that the reactant fluid stream contacts an electrode. The heat transfer liquid is other than water. Preferably, the method further comprises recirculating heat transfer liquid which is in the reactant exhaust stream, typically via a heat exchanger, and re-introducing it into the fuel cell assembly in the reactant fluid stream. The recirculated heat transfer liquid may be directed to a reservoir which in turn supplies heat transfer liquid to the reactant fluid stream as it is needed. In a further embodiment, the method may comprise using the heat transfer liquid to heat a fuel cell stack to a desired operating temperature rather than cooling the stack.

Method and apparatus for controlling the temperature within an electrochemical fuel cell

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

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Burnaby, Canada

Bien Hung Chiem