Method and apparatus for operating an electrochemical fuel cell
AssigneeBallard Power Systems Inc.
InventorsGregory James, Rajeev Vohra
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Abstract
An operating method increases fuel cell life or durability, particularly that of a solid polymer electrolyte fuel cell. The fuel cell has a mean life expectancy that may be empirically determined. The method comprises the step of reversing the direction of flow of at least one of the fluids supplied to the fuel cell (for example, the fuel and/or oxidant reactants) through its corresponding flow field after a time period of operation of the fuel cell. The time period is less than the mean life expectancy of the cell and has a value that is a substantial part of the mean life expectancy. The flow may be reversed once or several times over the life of the fuel cell. An improved apparatus carries out the method.
Claims12
A method of operating a fuel cell supplied with a fluid stream, said fuel cell having a mean life expectancy, wherein said mean life expectancy is determined by averaging a plurality of life expectancies of a plurality of fuel cells, said method comprising the step of reversing the direction of flow of said fluid stream after a time period of operation of said fuel cell, wherein said time period is less than said mean life expectancy and said time period is a substantial part of said mean life expectancy.
Dependencies are inferred from the claim text.