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AssigneeBallard Power Systems Inc.
InventorsDavid P. Wilkinson, Stephen A. Campbell, Joy A. Roberts
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A method is provided for treating electrocatalyst particles and using the treated electrocatalyst for improving performance in an electrochemical fuel cell. The treatment method comprises impregnating pores of the electrocatalyst particles with an impregnant wherein the pores comprise micropores which have an aperture size less than 0.1 micron. The impregnant is preferably ion-conducting and may comprise an organic acid, an inorganic acid, or a polymer. Alternatively, or in addition, the impregnant has an oxygen permeability greater than that of water. The method of impregnating the electrocatalyst particles preferably comprises the steps of contacting the electrocatalyst particles with an impregnant and subjecting the electrocatalyst particles to a vacuum and/or an elevated pressure above atmospheric pressure. The treated electrocatalyst particles are incorporated into an electrochemical fuel cell. The impregnant improves the mass transport properties for the movement of reactants and reaction products within the micropores of the electrocatalyst particles, thereby improving electrocatalyst utilization and electrochemical fuel cell performance for a fixed amount of electrocatalyst.
A method of improving electrochemical fuel cell performance, the method comprising incorporating porous electrocatalyst particles in said electrochemical fuel cell at an interface between an electrode and an electrolyte, wherein micropores in said electrocatalyst particles have been impregnated with an impregnant which comprises an ion-conducting material that is an acid.
A method of improving electrochemical fuel cell performance, the method comprising incorporating porous electrocatalyst particles in said electrochemical fuel cell at an interface between an electrode and an electrolyte, wherein micropores in said electrocatalyst particles have been impregnated with an impregnant which comprises an organic fluid which is a perfluorocarbon, wherein said organic fluid with oxygen permeability greater than that of water and wherein said perfluorocarbon is selected from the group consisting of perfluorotripropylamine, cis-perfluorodecalin, trans-perfluorodecalin, perfluoro-1-methyl decalin, perfluoroisopentyltetrahydropyrane, perfluoro-N,N-dimethylcyclohexylamine, perfluoroperhydrophenanthrene, and perfluorotributylamine.
A method of improving electrochemical fuel cell performance, the method comprising incorporating porous electrocatalyst particles in said electrochemical fuel cell at an interface between an electrode and an electrolyte, wherein micropores in said electrocatalyst particles have been impregnated with an impregnant which comprises an organic fluid with oxygen permeability greater than that of water and wherein said organic fluid is silicone oil or mineral oil.
A method of impregnating porous electrocatalyst particles to deposit an impregnant within pores thereof having an aperture size less than 0.1 micron, said method comprising contacting said electrocatalyst particles with said impregnant at a pressure below atmospheric pressure, and further comprising contacting said electrocatalyst particles with said impregnant at a pressure above atmospheric pressure.
A method of impregnating porous electrocatalyst particles to deposit an impregnant within pores having an aperture size less than 0.1 micron, said method comprising the step of contacting said electrocatalyst particles with said impregnant at a pressure above atmospheric pressure.
An electrochemical fuel cell comprising:
Dependencies are inferred from the claim text.