# US 10,770,736 B2 · Via designs for removing water in fuel cell stacks > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,770,736 B2 - Document ID: US10770736B2 - Status: Granted - Kind: B2 - Application number: 16/165,004 - Filed: 2018-10-19 - Published: 2019-04-25 - Granted: 2020-09-08 - Earliest claimed: 2017-10-25 - Assignees: Daimler AG; Ford Motor Company - Applicants: Daimler AG; Ford Motor Company - Inventors: Alireza Roshanzamir; Yunsong Yang - Web page: https://patentgrep.com/patent/US10770736B2 ## CPC - H01M 8/0258: characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant - H01M 8/04156: {with product water removal} - H01M 8/04171: {using adsorbents, wicks or hydrophilic material} - H01M 8/04291: Arrangements for managing water in solid electrolyte fuel cell systems (H01M8/04119 takes precedence) - H01M 8/04835: {of fuel cell reactants} - H01M 8/1018: Polymeric electrolyte materials - H01M 2008/1095: {Fuel cells with polymeric electrolytes} - H01M 2300/0082: Organic polymers - Y02E 60/50: Fuel cells - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## 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. ## Claims ### Claim 1 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. ### Claim 2 (depends on 1) The fuel cell of claim 1 wherein: the oxidant flow field plate comprises a plurality of oxidant flow field channels, an oxidant outlet transition region, at least one oxidant outlet via, and an oxidant outlet port wherein the plurality of oxidant flow field channels is fluidly connected to the oxidant outlet transition region, the oxidant outlet transition region is fluidly connected to the at least one oxidant outlet via, and the at least one oxidant outlet via is fluidly connected to the oxidant outlet port; wherein the plurality of reactant flow field channels is the plurality of oxidant flow field channels, the reactant transition region is the oxidant outlet transition region, the superhydrophobic reactant via is the oxidant outlet via, and the reactant port is the oxidant outlet port. ### Claim 3 (depends on 1) The fuel cell of claim 1 wherein: the fuel flow field plate comprises a plurality of fuel flow field channels, a fuel outlet transition region, at least one fuel outlet via, and a fuel outlet port wherein the plurality of fuel flow field channels is fluidly connected to the fuel outlet transition region, the fuel outlet transition region is fluidly connected to the at least one fuel outlet via, and the at least one fuel outlet via is fluidly connected to the fuel outlet port; wherein the plurality of reactant flow field channels is the plurality of fuel flow field channels, the reactant transition region is the fuel outlet transition region, the superhydrophobic reactant via is the fuel outlet via, and the reactant port is the fuel outlet port. ### Claim 4 (depends on 1) The fuel cell of claim 1 wherein the distance between the first end of the hydrophilic additional via and the first end of the superhydrophobic reactant via is less than two times the width of the channels in the plurality of reactant flow field channels. ### Claim 5 (depends on 1) The fuel cell of claim 1 wherein the width dimension of the hydrophilic additional via is less than or about equal to the width dimension of the superhydrophobic reactant via. ### Claim 6 (depends on 1) The fuel cell of claim 1 wherein the second end of the hydrophilic additional via is fluidly connected directly to the second end of the superhydrophobic reactant via. ### Claim 7 (depends on 1) The fuel cell of claim 1 comprising a plurality of reactant vias having first and second ends and whose surfaces are superhydrophobic wherein the reactant transition region is fluidly connected to the first ends of the plurality of superhydrophobic reactant vias and the second ends of the plurality of superhydrophobic reactant vias are fluidly connected to the reactant port. ### Claim 8 (depends on 7) The fuel cell of claim 7 comprising a plurality of additional vias having first and second ends wherein: the surfaces of the additional vias are hydrophilic; each of the hydrophilic additional vias is fluidly connected in parallel to one of the superhydrophobic reactant vias such that the first end of each of the hydrophilic additional vias is fluidly connected directly to the reactant transition region and the second end of each of the hydrophilic additional vias is fluidly connected directly to one of the superhydrophobic reactant vias; and the dimensions of the hydrophilic additional vias are such that water appearing at their second ends will flow into the hydrophilic additional vias by capillary action. ### Claim 9 (depends on 1) The fuel cell of claim 1 wherein the hydrophilic additional via is also fluidly connected by at least one branch to the superhydrophobic reactant via between its first and second ends. ### Claim 10 (depends on 1) The fuel cell of claim 1 wherein the reactant transition region comprises structures selected from the group consisting of vanes and pillars. ### Claim 11 (depends on 1) The fuel cell of claim 1 wherein the reactant port is near the periphery of the reactant flow field plate. ### Claim 12 (depends on 1) The fuel cell of claim 1 wherein the fuel cell comprises a cathode gas diffusion layer between the cathode and the oxidant flow field plate and an anode gas diffusion layer located between the anode and the fuel flow field plate. ### Claim 13 (depends on 1) A solid polymer electrolyte fuel cell stack comprising a series stack of a plurality of the solid polymer electrolyte fuel cells of claim 1. ### Claim 14 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. ### Claim 15 (depends on 14) The method of claim 14 wherein structures are incorporated in the reactant transition region to direct fluid flow towards the first end of the superhydrophobic reactant via and the first end of the hydrophilic additional via. ### Claim 16 (depends on 14) The method of claim 14 wherein the hydrophilic additional via is incorporated such that the distance between the first end of the hydrophilic additional via and the first end of the superhydrophobic reactant via is less than the width of the channels in the plurality of reactant flow field channels. ### Claim 17 (depends on 14) The method of claim 14 wherein the hydrophilic additional via is incorporated such that its second end is fluidly connected directly to the second end of the superhydrophobic reactant via. ### Claim 18 (depends on 14) The method of claim 14 wherein the fuel cell comprises a plurality of reactant vias having first and second ends and whose surfaces are superhydrophobic, wherein the reactant transition region is fluidly connected to the first ends of the plurality of superhydrophobic reactant vias and the second ends of the plurality of superhydrophobic reactant vias are fluidly connected to the reactant port, the method additionally comprising: incorporating a plurality of additional vias having first and second ends into the fuel cell wherein: the surfaces of the additional vias are hydrophilic; each of the hydrophilic additional vias is fluidly connected in parallel to one of the superhydrophobic reactant vias such that the first end of each of the hydrophilic additional vias is fluidly connected directly to the reactant transition region and the second end of each of the hydrophilic additional vias is fluidly connected directly to one of the superhydrophobic reactant vias; and the dimensions of the hydrophilic additional vias are such that water appearing at their second ends will flow into the hydrophilic additional vias by capillary action. ### Claim 19 (depends on 14) The method of claim 14 comprising incorporating at least one branch fluidly connecting the hydrophilic additional via to the superhydrophobic reactant via between its first and second ends.