Abstract: An illustrative method of making a fuel cell component includes obtaining at least one blank plate including graphite and a polymer; establishing a temperature of the blank that is sufficient to maintain the polymer in an at least partially molten state; and applying a compression molding force to the blank until the polymer is essentially solidified to form a plate including a plurality of channels on at least one side of the plate. The blank plate has a central area having a first thickness. The blank plate also has two generally parallel edges on opposite sides of the central area. The edges have a second thickness that is greater than the first thickness.

Abstract: A composite plate (26) is formed in a mold (8) by placing one of two preforms (15, 23) of between about 80 wt. % and about 85 wt. % flake graphite, balance polymer binder, into the mold and disposing a coolant tube array (18) thereon, depositing a powder (21) of the flake/polymer around the tube array, placing a second preform on the powder and a mold plunger (27) on the second preform, heating the mold to the melting temperature of the polymer under a pressure of 625 psi (4311 kPa), cooling the mold to the solidification temperature of the polymer while still under pressure, cooling the mold further, disassembling the mold, and removing the composite plate. The composite plate has reactant gas flow field channels (31, 32) in major surfaces thereof, is devoid of any acid edge protection layer or film and is devoid of any acid impervious separator plate between either of the fuel cell reactant gas flow fields and the coolant tube array.

Abstract: The method includes dispensing carbon fibers having a length of between about 3 and 12 millimeters from a first hopper into a raizing chamber of a double-hopper, bladed-roiler scattering machine and simultaneously depositing a thermoset resin powder from a second hooper of the scattering machine into the mixing chamber where in the fibers and powder are mixed to homogenous predetermined proportions of between about 40% and 60% each. Then, the mixture is directed to flew onto a moving support belt of a double belt press apparatus and the mixture is compressed between the moving support belt and a moving compression belt of the double belt press apparatus and the mixture passes between the belts for an adequate residence time duration to first melt and then cure the thermoset resin to form the fuel cell precursor substrate. Carbonizing and then graphitizing the precursor substrate forms the final substrate.

Abstract: An illustrative example cell stack assembly includes a plurality of fuel cells that each include a cathode electrode, an anode electrode and a matrix for holding a liquid acid electrolyte. The electrodes have lateral outside edges that are generally coplanar. A plurality of separator plates are respectively between the cathode electrode of one of the fuel cells and the anode electrode of an adjacent one of the fuel cells. The separator plates have lateral outside edges that are generally coplanar with the lateral outside edges of the electrodes. A plurality of barriers along at least one of the lateral outside edges of respective ones of the separator plates extend outwardly beyond the lateral outside edges of the electrodes and separator plates. The barriers inhibit acid migration between one of the electrodes on one side of the barrier and one of the electrodes on an opposite side of the barrier.

Abstract: A stack (10) of fuel cells (11) is manufactured with barriers (32) to prevent migration of a liquid electrolyte (such as phosphoric acid) out of the cells (11). The barrier (32) is secured within a step (34) formed within a land region (28) of a separator plate assembly (18) and extends from an edge (30) of the separator plate assembly (18) all or a portion of a distance between the edge (30) and a flow channel (24) defined within the separator plate assembly (18). The barrier (32) also extends away from the edge (30) a distance of between 0.051 and about 2.0 millimeters (about 2 and about 80 mils. The barrier (32) includes a hydrophobic, polymeric film (36), a pressure sensitive adhesive (38) as an assembly aid, and a fluoroelastomer bonding agent (40).

Abstract: An illustrative example cell stack assembly includes a plurality of fuel cells that each include a cathode electrode, an anode electrode and a matrix for holding a liquid acid electrolyte. The electrodes have lateral outside edges that are generally coplanar. A plurality of separator plates are respectively between the cathode electrode of one of the fuel cells and the anode electrode of an adjacent one of the fuel cells. The separator plates have lateral outside edges that are generally coplanar with the lateral outside edges of the electrodes. A plurality of barriers along at least one of the lateral outside edges of respective ones of the separator plates extend outwardly beyond the lateral outside edges of the electrodes and separator plates. The barriers inhibit acid migration between one of the electrodes on one side of the barrier and one of the electrodes on an opposite side of the barrier.

Abstract: A stack (10) of fuel cells (11) is provided with barriers (32) to prevent migration of a liquid electrolyte (such as phosphoric acid) out of the cells (11). The barrier (32) is secured within a step (34) defined within a land region (28) of a separator plate assembly (18) and extends from an edge (30) of the separator plate assembly (18) all or a portion of a distance between the edge (30) and a flow channel (24) defined within the separator plate assembly (18). The barrier (32) also extends away from the edge (30) a distance of between 0.051 and 2.0 millimeters (2 and 80 mils). The barrier (32) includes a hydrophobic, polymeric film (36), a pressure sensitive adhesive (38), as an assembly aid, and a fluoroelastomer bonding agent (40).

Abstract: An end-cooler assembly for a fuel cell includes a cooler having a coolant tube array. A composite material includes flake graphite and hydrophobic polymer. The composite material surrounds the coolant tube array and provides a first side. A flow field is formed in the first side. A thermal dam is embedded in and is entirely surrounded by the composite material. The thermal dam is arranged between the coolant tube array and the flow field. The coolant tube array, composite material, flow field and thermal dam comprise a unitary, monolithic structure bound together by the composite material.

Abstract: A fuel cell separator plate includes flake graphite particles having a length along a planar direction and a thickness along a generally perpendicular direction. The flake graphite has an aspect ratio of length to thickness that is less than ten.

Abstract: An illustrative method of making a fuel cell component includes obtaining at least one blank plate including graphite and a polymer; establishing a temperature of the blank that is sufficient to maintain the polymer in an at least partially molten state; and applying a compression molding force to the blank until the polymer is essentially solidified to form a plate including a plurality of channels on at least one side of the plate. The blank plate has a central area having a first thickness. The blank plate also has two generally parallel edges on opposite sides of the central area. The edges have a second thickness that is greater than the first thickness.

Abstract: The method includes dispensing carbon fibers having a length of between about 3 and 12 millimeters from a first hopper into a raizing chamber of a double-hopper, bladed-roiler scattering machine and simultaneously depositing a thermoset resin powder from a second hooper of the scattering machine into the mixing chamber where in the fibers and powder are mixed to homogenous predetermined proportions of between about 40% and 60% each. Then, the mixture is directed to flew onto a moving support belt of a double belt press apparatus and the mixture is compressed between the moving support belt and a moving compression belt of the double belt press apparatus and the mixture passes between the belts for an adequate residence time duration to first melt and then cure the thermoset resin to form the fuel cell precursor substrate. Carbonizing and then graphitizing the precursor substrate forms the final substrate.

Abstract: A method of heat treating a substrate for a fuel cell includes stacking substrates to form a group. A dimension is determined for a plate corresponding to a resulting mass that is less than a predetermined mass. The plate is arranged above the group to apply a weight of the plate to the group. The resulting masses for spacer plates and intermediate lifting plates, for example, are minimized to reduce the pressure differential between the bottom and top substrates in the heat treat assembly. In another disclosed method, a dimension for a plate, such as a top plate, is determined that corresponds to a resulting mass that is greater than a predetermined mass. The plate is arranged above the group to apply a weight of the plate to the group. The top plate resulting mass is selected to minimize a variation in the average pressure of the substrates throughout the heat treat assembly.

Abstract: A composite plate (26) is formed in a mold (8) by placing one of two preforms (15, 23) of between about 80 wt.% and about 85 wt.% flake graphite, balance polymer binder, into the mold and disposing a coolant tube array (18) thereon, depositing a powder (21) of the flake/polymer around the tube array, placing a second preform on the powder and a mold plunger (27) on the second preform, heating the mold to the melting temperature of the polymer under a pressure of 625 psi (4311 kPa), cooling the mold to the solidification temperature of the polymer while still under pressure, cooling the mold further, disassembling the mold, and removing the composite plate. The composite plate has reactant gas flow field channels (31, 32) in major surfaces thereof, is devoid of any acid edge protection layer or film and is devoid of any acid impervious separator plate between either of the fuel cell reactant gas flow fields and the coolant tube array.

Abstract: An end-cooler assembly for a fuel cell includes a cooler having a coolant tube array. A composite material includes flake graphite and hydrophobic polymer. The composite material surrounds the coolant tube array and provides a first side. A flow field is formed in the first side. A thermal dam is embedded in and is entirely surrounded by the composite material. The thermal dam is arranged between the coolant tube array and the flow field. The coolant tube array, composite material, flow field and thermal dam comprise a unitary, monolithic structure bound together by the composite material.

Abstract: A fuel cell separator plate assembly (20) includes a separator plate layer (22) and flow field layers (24, 26). In one disclosed example, the separator plate layer (22) comprises graphite and a hydrophobic resin. The hydrophobic resin of the separator plate layer (22) serves to secure the separator plate layer to flow field layers on opposite sides of the separator plate layer. In one example, at least one of the flow field layers (24, 26) comprises graphite and a hydrophobic resin such that the flow field layer is hydrophobic and nonporous. In another example, two graphite and hydrophobic resin flow field layers are used on opposite sides of a separator plate layer. One disclosed example includes all three layers comprising graphite and a hydrophobic resin.

Abstract: A fuel cell assembly (20) has an extended operational life, in part, because of unique startup and shutdown procedures used for operating the fuel cell assembly. In disclosed examples, a purge gas mixture of hydrogen and nitrogen includes less than 2% hydrogen for selectively purging portions of the assembly during a startup or shutdown procedure. In a disclosed example, the hydrogen-nitrogen mixture contains less than 0.1% hydrogen.

Abstract: A method of heat treating a substrate for a fuel cell includes stacking substrates to form a group. A dimension is determined for a plate corresponding to a resulting mass that is less than a predetermined mass. The plate is arranged above the group to apply a weight of the plate to the group. The resulting masses for spacer plates and intermediate lifting plates, for example, are minimized to reduce the pressure differential between the bottom and top substrates in the heat treat assembly. In another disclosed method, a dimension for a plate, such as a top plate, is determined that corresponds to a resulting mass that is greater than a predetermined mass. The plate is arranged above the group to apply a weight of the plate to the group. The top plate resulting mass is selected to minimize a variation in the average pressure of the substrates throughout the heat treat assembly.

Abstract: A fuel cell 12 has a liquid electrolyte 20, a cathode electrode 28, and an anode electrode 26. The fuel cell includes an electrolyte condensation zone 58 extending from an edge 56 of a first catalyst layer 36 on the cathode electrode to an outer edge 48 of an edge seals 52 and 49. An anode electrode has an anode catalyst layer 30 with an end substantially coinciding with an inner edge 53 of the edge seals. The acid condensation zone is located near the reactant exit, so that electrolyte that has evaporated into the reactant stream can condense out before leaving the fuel cell for re-absorption back into the fuel cell.

Abstract: A method of making an electrochemical cell electrode substrate includes creating an aqueous or dry mixture of chopped carbon fibers, chopped cross-linkable resin fibers that are still fuseable after being formed into a felt, such as novolac, a temporary binder, such as polyvinyl alcohol fiber or powder, forming a non-woven felt from either an aqueous suspension of the aqueous mixture or an air suspension of the dry mixture, by a non-woven, wet-lay or dry-lay, respectively, felt forming process, a resin curing agent, such as hexamethylene tetramine may be included in the aqueous or dry mixture, or it may be coated onto the formed felt; pressing one or more layers of the formed felt for 1-5 minutes to a controlled thickness and a controlled porosity at a temperature at which the resin melts, cross-links and then cures, such as 150° C.-200° C.; and heat treating the pressed felt in a substantially inert atmosphere, first to 750° C.-1000° C. and then to 1000° C.-3000° C.

Abstract: A fuel cell (8a) having a matrix (11) for containing phosphoric acid (or other liquid) electrolyte with an anode catalyst (12) on one side and a cathode catalyst (13) on the other side includes an anode substrate (16a) in contact with the anode catalyst and a cathode substrate (17a) in contact with the cathode catalyst, the anode substrate being thicker than the cathode substrate by a ratio of between 1.75 to 1.0 and 3.0 to 1.0. Non-porous, hydrophobic separator plate assemblies (19) provide fuel flow channels (20) and oxidant flow channels (21) as well as demarcating the fuel cells.