Abstract: A redox flow battery system is provided. The system includes a positive electrode in fluid communication with a positive electrolyte comprising a first metal ion and a negative electrode in fluid communication with a negative electrolyte comprising a second metal ion. An electrically insulating ion conducting surface is provided separating the positive electrode from the negative electrode. Further, the system includes a catalyst surface in fluid communication with the first metal ion, the second metal ion, or a combination thereof, and hydrogen gas, wherein the hydrogen gas and the first metal ion, the second metal ion, or a combination thereof are fluidly contacted at the catalyst surface.

Abstract: A method of rebalancing electrolytes in a redox flow battery system comprises directing hydrogen gas generated on the negative side of the redox flow battery system to a catalyst surface, and fluidly contacting the hydrogen gas with an electrolyte comprising a metal ion at the catalyst surface, wherein the metal ion is chemically reduced by the hydrogen gas at the catalyst surface, and a state of charge of the electrolyte and pH of the electrolyte remain substantially balanced.

Abstract: A method of rebalancing electrolytes in a redox flow battery system comprises directing hydrogen gas generated on the negative side of the redox flow battery system to a catalyst surface, and fluidly contacting the hydrogen gas with an electrolyte comprising a metal ion at the catalyst surface, wherein the metal ion is chemically reduced by the hydrogen gas at the catalyst surface, and a state of charge of the electrolyte and pH of the electrolyte remain substantially balanced.

Abstract: An electrode for use in an all-iron redox flow battery is provided. In one example, the electrode may include a plastic mesh; and a coating on the plastic mesh. The coating may be a hydrophilic coating or a conductive coating and the electrode may have an electrode reaction potential is less than 0.8V. Further, a method of manufacturing a coated plastic mesh electrode for use in an all-iron redox flow battery is provided. In one example method, the steps include fabricating a plastic mesh, treating the plastic mesh by applying a solvent treatment or a plasma treatment or a mechanical abrasion treatment; coating the plastic mesh with a material selected from: carbon inks, metal oxides, and hydrophilic polymers.

Abstract: Methods and systems are provided which maintain the positive and negative electrolyte pH and stability of a redox flow battery through the use of electrochemical rebalancing cells. The electrochemical cells may be activated by applying an electrical load to affect changes to the pH of the electrolytes. The use of the electrochemical cells improves long term performance stability redox flow batteries by decreasing and/or eliminating Fe(OH)3 precipitation formation.

Abstract: A method of rebalancing electrolytes in a redox flow battery system comprises directing hydrogen gas generated on the negative side of the redox flow battery system to a catalyst surface, and fluidly contacting the hydrogen gas with an electrolyte comprising a metal ion at the catalyst surface, wherein the metal ion is chemically reduced by the hydrogen gas at the catalyst surface, and a state of charge of the electrolyte and pH of the electrolyte remain substantially balanced.

Abstract: An iron redox flow battery system, comprising a redox electrode, a plating electrolyte tank, a plating electrode, a redox electrolyte tank with additional acid additives that may be introduced into the electrolytes in response to electrolyte pH. The acid additives may act to suppress undesired chemical reactions that create losses within the battery and may be added in response to sensor indications of these reactions.

Abstract: To mitigate bubble blockage in water passageways (78, 85), in or near reactant gas flow field plates (74, 81) of fuel cells (38), passageways are configured with (a) intersecting polygons, obtuse angles including triangles, trapezoids, or (b) hydrophobic surfaces (111), or (c) differing adjacent channels (127, 128), or (d) water permeable layers (93, 115, 116, 119) adjacent to water channels or hydrophobic/hydrophilic layers (114, 120).

Abstract: Embodiments are disclosed that relate to increasing radiative heat transfer in a steam reformer from an exterior shell which includes a diffusion burner to an interior reactor via angled fins coupled to the exterior shell. For example, one disclosed embodiment provides a steam reformer, comprising an exterior shell which includes a diffusion burner and angled fins, the angled fins extending away from an inner surface of the exterior shell and downward toward the diffusion burner. The steam reformer further comprises an interior reactor positioned at least partly within the exterior shell.

Abstract: A method for controlling an amount of a liquid electrolyte in a polymer-electrolyte membrane of a fuel cell is provided. The method comprises enriching one or more of a fuel flow and an air flow with a vapor of the liquid electrolyte, the liquid electrolyte being unreplenishable via an electrochemical reaction of the fuel cell. The method further comprises delivering the vapor of the liquid electrolyte to the fuel cell including the polymer-electrolyte membrane via one or more of the gas-permeable anode and or the gas-permeable cathode. In this manner, loss of liquid electrolyte from the PEM membrane of the fuel cell can be reduced, leading to improved fuel-cell endurance.

Abstract: Embodiments are disclosed that relate to increasing radiative heat transfer in a steam reformer from an exterior shell which includes a diffusion burner to an interior reactor via angled fins coupled to the exterior shell. For example, one disclosed embodiment provides a steam reformer, comprising an exterior shell which includes a diffusion burner and angled fins, the angled fins extending away from an inner surface of the exterior shell and downward toward the diffusion burner. The steam reformer further comprises an interior reactor positioned at least partly within the exterior shell.

Abstract: A method for controlling an amount of a liquid electrolyte in a polymer-electrolyte membrane of a fuel cell is provided. The method comprises enriching one or more of a fuel flow and an air flow with a vapor of the liquid electrolyte, the liquid electrolyte being unreplenishable via an electrochemical reaction of the fuel cell. The method further comprises delivering the vapor of the liquid electrolyte to the fuel cell including the polymer-electrolyte membrane via one or more of the gas-permeable anode and or the gas-permeable cathode. In this manner, loss of liquid electrolyte from the PEM membrane of the fuel cell can be reduced, leading to improved fuel-cell endurance.

Abstract: A fuel cell power plant assembly includes an accumulator having a housing. In one example, at least one demineralizer portion is positioned to interact with fluid within the accumulator housing. This allows for warm fluid within the accumulator housing to provide heat to the demineralizer portion. In one example, the demineralizer portion is within the housing. Another example includes a separator supported within the housing of the accumulator. A disclosed example includes a conical shaped baffle as the separator. The separator separates liquid from gas and facilitates distributing fluid flow within the accumulator housing to provide increased heat exchange with the demineralizer portion within the housing.

Abstract: Embodiments are disclosed that relate to increasing radiative heat transfer in a steam reformer from an exterior shell which includes a diffusion burner to an interior reactor via angled fins coupled to the exterior shell. For example, one disclosed embodiment provides a steam reformer, comprising an exterior shell which includes a diffusion burner and angled fins, the angled fins extending away from an inner surface of the exterior shell and downward toward the diffusion burner. The steam reformer further comprises an interior reactor positioned at least partly within the exterior shell.

Abstract: A polymer electrolyte membrane (PEM) fuel cell power plant is cooled evaporatively with a water coolant system which does not permit liquid water to exit or flow through the coolant system. The coolant system utilizes a hydrophobic porous member (28) for venting gases such as fuel and/or air from a coolant water flow field in the system. Coolant water (36) is prevented from continuosly contacting the porous member during operation of the power plant thus preventing blockage of the porous member by coolant water or contaminants disposed in the coolant water.

Abstract: A method for controlling an amount of a liquid electrolyte in a polymer-electrolyte membrane of a fuel cell is provided. The method comprises enriching one or more of a fuel flow and an air flow with a vapor of the liquid electrolyte, the liquid electrolyte being unreplenishable via an electrochemical reaction of the fuel cell. The method further comprises delivering the vapor of the liquid electrolyte to the fuel cell including the polymer-electrolyte membrane via one or more of the gas-permeable anode and or the gas-permeable cathode. In this manner, loss of liquid electrolyte from the PEM membrane of the fuel cell can be reduced, leading to improved fuel-cell endurance.

Abstract: Embodiments are disclosed that relate to increasing a temperature in a low temperature zone in a steam reforming reactor via a radiative heating shunt. For example, one disclosed embodiment provides a steam reforming reactor comprising a reaction chamber having an interior surface, a packing material located within the reaction chamber, and a radiative heating shunt extending from the interior surface into the reaction chamber. The radiative heating shunt comprises a porous partition enclosing a sub-volume of the reaction chamber bounded by the porous partition and a portion of the interior surface, the sub-volume being at least partly free of packing material such that radiative heat has a path from the interior surface to a distal portion of the porous partition that is unobstructed by packing material.

Abstract: Embodiments are disclosed that relate to increasing a temperature in a low temperature zone in a steam reforming reactor via a radiative heating shunt. For example, one disclosed embodiment provides a steam reforming reactor comprising a reaction chamber having an interior surface, a packing material located within the reaction chamber, and a radiative heating shunt extending from the interior surface into the reaction chamber. The radiative heating shunt comprises a porous partition enclosing a sub-volume of the reaction chamber bounded by the porous partition and a portion of the interior surface, the sub-volume being at least partly free of packing material such that radiative heat has a path from the interior surface to a distal portion of the porous partition that is unobstructed by packing material.

Abstract: To mitigate bubble blockage in water passageways (78, 85), in or near reactant gas flow field plates (74, 81) of fuel cells (38), passageways are configured with (a) cross sections having intersecting polygons or other shapes, obtuse angles including triangles and trapezoids, or (b) hydrophobic surfaces (111), or (c) differing adjacent channels (127, 128), or (d) water permeable layers (93, 115, 116, 119) adjacent to water channels or hydrophobic/hydrophilic layers (114, 120), or (e) diverging channels (152).

Abstract: Embodiments are disclosed that relate to increasing radiative heat transfer in a steam reformer from an exterior shell which includes a diffusion burner to an interior reactor via angled fins coupled to the exterior shell. For example, one disclosed embodiment provides a steam reformer, comprising an exterior shell which includes a diffusion burner and angled fins, the angled fins extending away from an inner surface of the exterior shell and downward toward the diffusion burner. The steam reformer further comprises an interior reactor positioned at least partly within the exterior shell.