Via designs for removing water in fuel cell stacks
AssigneesDaimler AG, Ford Motor Company
InventorsAlireza Roshanzamir, Yunsong Yang
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Abstract
Structures and methods are disclosed for removing water, and particularly for preventing ice blockages, in solid polymer electrolyte fuel cells comprising reactant vias that fluidly connect a reactant transition region to a reactant port. Water can be removed from the reactant via by making its surface superhydrophobic while incorporating at least one additional via with a hydrophilic surface in parallel therewith.
Claims19
A solid polymer electrolyte fuel cell comprising:
- a solid polymer electrolyte;
- a cathode and an anode on opposite sides of the electrolyte;
- an oxidant flow field plate for an oxidant reactant on the side of the cathode opposite the electrolyte;
- and
- a fuel flow field plate for a fuel reactant on the side of the anode opposite the electrolyte;
- wherein at least one of the oxidant and fuel flow field plates comprises a plurality of reactant flow field channels, a reactant transition region, at least one reactant via having first and second ends, and a reactant port;
- and wherein the plurality of reactant flow field channels is fluidly connected to the reactant transition region, the reactant transition region is fluidly connected to the first end of the at least one reactant via, and the second end of the at least one reactant via is fluidly connected to the reactant port;
- characterized in that:
- the surface of the at least one reactant via in the reactant flow field plate is superhydrophobic;
- and
- the fuel cell comprises at least one additional via having first and second ends wherein:
- the surface of the additional via is hydrophilic;
- the hydrophilic additional via is fluidly connected in parallel to the superhydrophobic reactant via such that the first end of the hydrophilic additional via is fluidly connected directly to the reactant transition region and the second end or at least one branch from the hydrophilic additional via is fluidly connected directly to the superhydrophobic reactant via;
- and
- the dimensions of the hydrophilic additional via are such that water appearing at its second end or the at least one branch will flow into the hydrophilic additional via by capillary action.
A method for removing water from at least one reactant via in a solid polymer electrolyte fuel cell, the fuel cell comprising a solid polymer electrolyte, a cathode and an anode on opposite sides of the electrolyte, an oxidant flow field plate for an oxidant reactant on the side of the cathode opposite the electrolyte, and a fuel flow field plate for a fuel reactant on the side of the anode opposite the electrolyte, wherein at least one of the oxidant and fuel flow field plates comprises a plurality of reactant flow field channels, a reactant transition region, the at least one reactant via having first and second ends, and a reactant port;
- and wherein the plurality of reactant flow field channels is fluidly connected to the reactant transition region, the reactant transition region is fluidly connected to the first end of the at least one reactant via, and the second end of the at least one reactant via is fluidly connected to the reactant port, the method comprising:
- making the surface of the at least one reactant via superhydrophobic;
- and
- incorporating at least one additional via having first and second ends into the fuel cell wherein:
- the surface of the additional via is hydrophilic;
- the hydrophilic additional via is fluidly connected in parallel to the superhydrophobic reactant via such that the first end of the hydrophilic additional via is fluidly connected directly to the reactant transition region and the second end or at least one branch from the hydrophilic additional via is fluidly connected directly to the superhydrophobic reactant via;
- and
- the dimensions of the hydrophilic additional via are such that water appearing at its second end or the at least one branch will flow into the hydrophilic additional via by capillary action.
Dependencies are inferred from the claim text.