Fuel Cell Flow Channels and Flow Fields

摘要

A fuel cell anode flow field includes at least one flow channel with a cross-sectional area that varies along at least a portion of its length. In some embodiments, the channel width decreases along at least a portion of the channel length according to a natural exponential function. This type of anode flow field can improve performance, reduce fuel consumption and/or reduce detrimental effects such as carbon corrosion and catalyst degradation, thereby improving fuel cell longevity and durability. When operating the fuel cell on either a substantially pure or a dilute fuel stream, this type of anode flow field can provide more uniform current density. These flow channels can be incorporated into reactant flow field plates, fuel cells and fuel cell stacks.

主权项

1. A fuel cell anode flow field plate comprising:
(a) a fuel inlet; (b) a fuel outlet; and (c) a channel formed in a major surface of said plate, said channel having a floor and a pair of side walls extending between said floor and said major surface, said channel having a length that fluidly interconnects said fuel inlet and said fuel outlet, said side walls separated by a distance defining a channel width, said floor and said major surface separated by a distance defining a channel depth, wherein said channel has a cross-sectional area that decreases exponentially along a portion of said channel length.