# US 11,309,569 B1 · Microwatt fuel cell stack > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,309,569 B1 - Document ID: US11309569B1 - Status: Granted - Kind: B1 - Application number: 16/541,228 - Filed: 2019-08-15 - Granted: 2022-04-19 - Earliest claimed: 2018-09-12 - Assignees: Triad National Security, LLC - Applicants: Triad National Security, LLC - Inventors: Mahlon Scott Wilson - Web page: https://patentgrep.com/patent/US11309569B1 ## CPC - H01M 8/241: with solid or matrix-supported electrolytes - H01M 8/0206: Metals or alloys - H01M 8/0215: Glass; Ceramic materials - H01M 8/0228: in the form of layered or coated products - H01M 8/023: Porous and characterised by the material - H01M 8/0247: characterised by the form (characterised by a channel configuration H01M8/0258) - H01M 8/0258: characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant - H01M 8/0278: {O-rings} - H01M 8/1007: with both reactants being gaseous or vaporised (H01M8/12 takes precedence) - H01M 8/1023: having only carbon, e.g. polyarylenes, polystyrenes or polybutadiene-styrenes - H01M 8/1039: halogenated, e.g. sulfonated polyvinylidene fluorides - H01M 8/2418: Grouping by arranging unit cells in a plane (H01M8/2425, H01M8/244 take precedence) - H01M 8/2483: characterised by internal manifolds - H01M 2008/1095: {Fuel cells with polymeric electrolytes} - 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 A microwatt fuel cell stack that demonstrates a wide range temperature tolerance, low reactant cross-over and leakage, low internal leakage current, and/or effective water transport is disclosed. Both H2 and O2 may be supplied directly to the fuel cell stack (i.e., dead-ended). One-piece gas diffusion electrodes (GDEs) may serve as both the active electrode and manifold port. Water removal may be accomplished by permeation through the membrane to “fins” exposed by notches in the bipolar plates and gaskets. ## Claims ### Claim 1 A fuel cell stack, comprising: a plurality of fuel cells comprising a plurality of layers, the plurality of fuel cells each comprising: a membrane, a first gasket on a side of the membrane, the first gasket comprising a first gas diffusion electrode (GDE) that, in operation, is provided with a hydrogen gas supply via a hydrogen manifold, and a second gasket on an opposite side of the membrane with respect to the first gasket, the second gasket comprising a second GDE that, in operation, is provided with an oxygen gas supply via an oxygen manifold, wherein a water permeability coefficient of the first gasket and the second gasket is greater than a gas permeability coefficient of the first gasket and the second gasket, the membrane comprises a plurality of fins, and the first gasket and the second gasket each comprise at least one notch such that at least one respective fin of the plurality of fins of the membrane is exposed by the at least one notch in the first gasket and the second gasket. ### Claim 2 (depends on 1) The fuel cell stack of claim 1, wherein each fuel cell of the plurality of fuel cells further comprises at least one bipolar plate with at least one notch matching the at least one notch of an adjacent one of the first gasket or the second gasket, and each fuel cell shares a bipolar plate with a fuel cell directly above and below it, with the exception of a top cell that does not have a bipolar plate above the top fuel cell and a bottom cell that does not have a bipolar plate below the bottom fuel cell. ### Claim 3 (depends on 2) The fuel cell stack of claim 2, wherein the at least one bipolar plate comprises titanium that is nitrided, platinum-coated, or gold coated, the membrane comprises a sulfonated tetrafluoroethylene-based fluoropolymer-copolymer, and the first GDE and the second GDE comprise platinum black. ### Claim 4 (depends on 1) The fuel cell stack of claim 1, wherein the first gasket and the second gasket are oriented in opposite directions with respect to one another such that the first GDE and the second GDE are properly oriented to interface with the hydrogen manifold or the oxygen manifold, respectively. ### Claim 5 (depends on 1) The fuel cell stack of claim 1, wherein the fuel cell stack is configured such that both hydrogen gas and oxygen gas are supplied directly to the fuel cell stack in a dead-ended configuration and air is not provided. ### Claim 6 (depends on 1) The fuel cell stack of claim 1, wherein the first GDE and the second GDE serve as both an active electrode and a manifold port for the hydrogen manifold and the oxygen manifold, respectively. ### Claim 7 (depends on 1) The fuel cell stack of claim 1, wherein each fuel cell comprises a barrier plate. ### Claim 8 (depends on 1) The fuel cell stack of claim 1, wherein each layer of each fuel cell comprises holes defining passageways for the hydrogen and oxygen manifolds, respectively. ### Claim 9 (depends on 8) The fuel cell stack of claim 8, wherein a bottom fuel cell of the plurality of fuel cells comprises an endplate that does not include holes for the hydrogen and oxygen manifolds. ### Claim 10 (depends on 8) The fuel cell stack of claim 8, wherein a bottom fuel cell of the plurality of fuel cells comprises an endplate comprising holes for the hydrogen and oxygen manifolds, the fuel cell stack further comprises respective plugs and O-ring seals for each manifold hole of the endplate, and the plugs are one or more orders of magnitude more permeable to water than gas to selectively remove water proximate to the plugs. ### Claim 11 (depends on 1) The fuel cell of claim 1, wherein the first GDE and the second GDE each comprise a tongue, a throat, and a head, and in operation, gas flows from the tongue through the throat and on to the head. ### Claim 12 (depends on 11) The fuel cell stack of claim 11, wherein the throat of the first GDE and the second GDE is flush with, and has a same compressed thickness as, the first gasket and the second gasket, respectively. ### Claim 13 (depends on 11) The fuel cell stack of claim 11, wherein the tongue and the throat connect the head of the first GDE and the second GDE to the hydrogen manifold and the oxygen manifold, respectively. ### Claim 14 A fuel cell, comprising: a membrane comprising a plurality of fins, a first gasket on a side of the membrane, the first gasket comprising a first gas diffusion electrode (GDE) that, in operation, is provided with a hydrogen gas supply via a hydrogen manifold, and a second gasket on an opposite side of the membrane with respect to the first gasket, the second gasket comprising a second GDE that, in operation, is provided with an oxygen gas supply via an oxygen manifold, wherein the first gasket and the second gasket each comprise at least one notch such that respective membrane fins are exposed by the at least one notch in the first gasket and the second gasket, and a water permeability coefficient of the first gasket and the second gasket is greater than a gas permeability coefficient of the first gasket and the second gasket. ### Claim 15 (depends on 14) The fuel cell of claim 14, further comprising: at least one bipolar plate with at least one notch matching the at least one notch of an adjacent one of the first gasket or the second gasket. ### Claim 16 (depends on 14) The fuel cell of claim 14, wherein the first gasket and the second gasket are oriented in opposite directions with respect to one another such that the first GDE and the second GDE are properly oriented to interface with the hydrogen manifold or the oxygen manifold, respectively, the fuel cell stack is configured such that both hydrogen gas and oxygen gas are supplied directly to the fuel cell stack in a dead-ended configuration and air is not provided, and the first GDE and the second GDE serve as both an active electrode and a manifold port for the hydrogen manifold and the oxygen manifold, respectively. ### Claim 17 (depends on 14) The fuel cell of claim 14, further comprising: holes defining passageways for the hydrogen and oxygen manifolds, respectively; an endplate comprising holes for the hydrogen and oxygen manifolds; and respective plugs and O-ring seals for each manifold hole of the endplate, wherein the plugs are one or more orders of magnitude more permeable to water than gas to selectively remove water proximate to the plugs. ### Claim 18 (depends on 14) The fuel cell of claim 14, wherein the first GDE and the second GDE each comprise a tongue, a throat, and a head, in operation, gas flows from the tongue through the throat and on to the head, the throat of the first GDE and the second GDE is flush with, and has a same compressed thickness as, the first gasket and the second gasket, respectively, and the tongue and the throat connect the head of the first GDE and the second GDE to the hydrogen manifold and the oxygen manifold, respectively. ### Claim 19 A microwatt fuel cell, comprising: a membrane comprising a plurality of fins, a first gasket on a side of the membrane, the first gasket comprising a first gas diffusion electrode (GDE) that, in operation, is provided with a hydrogen gas supply via a hydrogen manifold, and a second gasket on an opposite side of the membrane with respect to the first gasket, the second gasket comprising a second GDE that, in operation, is provided with an oxygen gas supply via an oxygen manifold, wherein the first GDE and the second GDE each comprise a tongue, a throat, and a head, the tongue and the throat connect the head of the first GDE and the second GDE to the hydrogen manifold and the oxygen manifold, respectively, a water permeability coefficient of the first gasket and the second gasket is greater than a gas permeability coefficient of the first gasket and the second gasket, and the first gasket and the second gasket each comprise at least one notch such that at least one respective fin of the plurality of fins of the membrane is exposed by the at least one notch in the first gasket and the second gasket.