Abstract: Substrates for producing oxygen electrodes, oxygen electrodes, electrochemical devices and productions methods are provided. Substrates include an intermediate microporous layer (MPL) attached to a porous transport layer (PTL) to interface between the PTL and the catalytic layer deposited on the MPL—to provide microstructure compatibility, improved adhesion and better performance of the oxygen electrode produced therefrom. The MPL corresponds to the PTL with respect to the types of metallic material, to provide good electric conductivity, while the metal particle sizes of the MPL are selected to modify the pore sizes of the PTL to reach a predefined pore size distribution of the substrate—which best supports printing, adhesion and performance of the catalyst layer on the substrate. Electrochemical devices such as fuel cells, electrolyzers and reversible devices may include the oxygen electrodes, which may be optimized for the specific application.

Abstract: Water electrolyzers, systems and methods are provided, which operate with saline water to produce hydrogen. Water electrolyzers comprise an electrode assembly configured to electrolyze received water to produce oxygen and hydrogen, and one or more diffusion layer(s) attached to one of the electrodes of the electrode assembly and configured to deliver the water for the electrolysis by excluding specified ions from received saline water. Excluding anions such as chloride ions and optionally cations from the received saline water enable maintaining the operation and efficiency of the water electrolyzers in spite of using un-deionized water for electrolysis. Ion exchange column(s) may be used to retain and/or regenerate the alkalinity (or possibly the acidity) in the electrolyzer if needed and to remove anions and optionally cations.

Abstract: Methods of preparing reinforced anion exchange membranes are provided, as well as produced membranes and corresponding devices utilizing the membranes. Methods comprise compounding a halide-functionalized polymer (selected to react with amines to yield anion-conducting quaternary amine groups) with thermoplastic polymer(s) (selected to support and/or reinforce the membrane), and with copolymer(s) (selected to enhance the compounding of the polymers)—by heating, mixing and cooling—to form blend pellets, extruding the blend pellets to form a blend film, cross-linking polymer(s), and functionalizing the blend film to prepare the anion exchange membrane. Functionalization comprises a quaternization step comprising reacting halogen groups of the first polymer with tertiary amines to produce the quaternary amine groups with ion-exchange functionality.

Abstract: Oxygen electrodes, production methods and reversible, alkaline or anion exchange membrane (AEM) electrochemical devices are provided. The oxygen electrodes are operable in the reversible devices both as cathodes of a fuel cell supporting an oxygen reduction reaction (ORR), and as anodes of an electrolyzer supporting an oxygen evolution reaction (OER). The oxygen electrodes comprise a substrate layer which may be a porous transport layer (PTL), possibly coated and/or hydrophobized, or a membrane; and a blend of catalysts which is deposited on the substrate layer to form a catalyst layer, and includes ORR catalyst (e.g., a platinum group metal), OER catalyst (e.g., nickel-based particles), and possibly binders such as ionomers, PTFE or other polymers that are resistant in alkaline environment, but with the catalyst layer and the substrate layer being devoid of elemental carbon.

Abstract: Methods of preparing cell element(s) that are operable in alkaline or anion exchange electrochemical devices are provided, as well as corresponding cell elements and electrochemical devices such as fuel cells, electrolyzers and reversible dual devices. Binder material is mixed with catalyst material and optionally ionomer material, and coated on support layer(s) and/or one or both side of a membrane, and the catalyst layers are hot-pressed briefly, to improve the adhesion of the layer and its cohesivity. Membrane electrode assemblies are prepared from the cell elements in various configurations of the catalyst layers with respect to the cell elements, and the added binder and hot pressing improve the long-term performance and durability of the electrochemical devices.

Abstract: Self-refueling power-generating systems and methods of configuring them are provided, which enable operation in a self-sustained manner, using no external resource for water, oxygen or hydrogen. The systems and methods determine the operation of reversible device(s) in fuel cell or electrolyzer mode according to power requirements and power availability, supply oxygen in a closed circuit, compressing received oxygen in the electrolyzer mode, and supplying water or dilute electrolyte in a closed circuit in conjunction with the closed oxygen supply circuit by separating oxygen produced by the reversible device(s) in the electrolyzer mode from the water or dilute electrolyte received from the reversible device(s). Membrane assemblies may comprise a binder and be hot-pressed to enhance their long-term performance and durability.

Abstract: Self-refueling power-generating systems and methods of configuring them are provided, which enable operation in a self-sustained manner, using no external resource for water, oxygen or hydrogen. The systems and methods determine the operation of reversible device(s) in fuel cell or electrolyzer mode according to power requirements and power availability, supply oxygen in a closed circuit, compressing received oxygen in the electrolyzer mode, and supplying water or dilute electrolyte in a closed circuit in conjunction with the closed oxygen supply circuit by separating oxygen produced by the reversible device(s) in the electrolyzer mode from the water or dilute electrolyte received from the reversible device(s). Membrane assemblies may comprise a binder and be hot-pressed to enhance their long-term performance and durability.

Abstract: Membrane assemblies for electrochemical devices are provided, along with methods and system for fabricating them. Membrane assemblies comprise anode layer(s) and cathode layer(s), separated by membranous separation layer(s) and all embedded in continuous polymerized ionomer material. In production, during continuous deposition of ionomer material on a substrate (e.g., by electrospinning or electrospraying), consecutive deposition stages of catalyst material and optionally binder material are performed. For example, anode particles, binder material and cathode particles may be deposited (e.g., by electrospraying or electrospinning, respectively) consecutively during the continuous deposition o the ionomer material. Self-refueling power-generating system are provided, which include reversible anion exchange membrane devices with disclosed membrane assemblies.

Abstract: Membrane assemblies and separation layer(s) for electrochemical devices such as fuel cells and/or electrolyzers are provided, as well as their production methods. The separation layer(s) include surface-charged particles such as LDH particles to strengthen the membranes, enhance their ionic conductivity and prevent or reduce membrane dehydration and/or chemical degradation. In various configurations a single or few, relatively thick separation layer(s) with surface-charged particles may be used, while in other configurations alternating layers of ionomeric material and layers with surface-charged particles may be used, optimizing ionic conductivity with mechanical strength. Thin protective layers with solids content up to 100% may be set adjacent to the electrodes, and the orientation of the surface-charged particles may be set to enhance the ion conductivity of the respective layer.

Abstract: Membrane electrode assemblies (MEA) and electrochemical devices such as fuel cells, electrolyzers and reversible devices are provided. The MEA comprises gas diffusion electrodes (GDEs) comprising respective gas diffusion layers (GDLs) coated with respective catalyst layers, and a thin membrane coated on either or both catalyst layers and having a total thickness of at most 30 microns. The GDEs are joined together to form the MEA with the thin membrane located between the catalyst layers, and the MEA is sealed and stacked to be operable in the electrochemical devices. Advantageously, using the GDEs to deposit the membrane enable forming very thin and efficient membranes.

Abstract: Methods of making alkaline exchange catalytic electrodes for electrochemical devices are provided, as well as fuel cells, electrolyzers and dual reversible devices with provided electrodes and/or membrane-electrode assemblies. Methods comprise preparing a catalyst dispersion by mixing catalyst nanoparticles and polymer precursor dispersion in a solvent. The polymer precursor(s) comprise multiple types of monomer units with multiple types of functional groups that include non-cationic functional group(s) and anion-conductive functional group(s). Consecutively, the catalyst dispersion is deposited on a functional substrate and the solvent is evaporated to form a catalyst layer, and then the non-cationic functional group(s) and/or the anion-conductive group(s) are crosslinked to stabilize the catalyst layer. Membrane-electrode assemblies may be formed by the provided methods, and used in various types of electrochemical devices.

Abstract: Self-refueling power-generating systems and methods of configuring them are provided, which enable operation in a self-sustained manner, using no external resource for water, oxygen or hydrogen. The systems and methods determine the operation of reversible device(s) in fuel cell or electrolyzer mode according to power requirements and power availability, supply oxygen in a closed circuit, compressing received oxygen in the electrolyzer mode, and supplying water or dilute electrolyte in a closed circuit in conjunction with the closed oxygen supply circuit by separating oxygen produced by the reversible device(s) in the electrolyzer mode from the water or dilute electrolyte received from the reversible device(s). Membrane assemblies may comprise a binder and be hot-pressed to enhance their long-term performance and durability.

Abstract: A method of making an alkaline membrane fuel cell assembly is disclosed. The method may include: depositing a first catalyst layer on a first gas diffusion layer to form a first gas diffusion electrode; depositing a second catalyst layer one a second gas diffusion layer to form a second gas diffusion electrode; depositing a thin membrane on at least one of: the first catalyst layer and the second catalyst layer; joining together the first and second gas diffusion electrodes to form the alkaline fuel cell assembly such that the thin membrane is located between the first and second catalyst layers; and sealing the first and second gas diffusion layers, the first and second catalyst layers and the thin membrane from all sides.

Abstract: Self-refueling power-generating systems and methods of configuring them are provided, which enable operation in a self-sustained manner, using no external resource for water, oxygen or hydrogen. The systems and methods determine the operation of reversible device(s) in fuel cell or electrolyzer mode according to power requirements and power availability, supply oxygen in a closed circuit, compressing received oxygen in the electrolyzer mode, and supplying water or dilute electrolyte in a closed circuit in conjunction with the closed oxygen supply circuit, by separating oxygen produced by the reversible device(s) in the electrolyzer mode from the water or dilute electrolyte received from the reversible device(s).

Abstract: Disclosed is a method of operating an Alkaline Membrane Fuel Cell (AMFC) with direct ammonia feeding. The method may include providing AMFC comprising an anode inlet for receiving ammonia and a cathode inlet for receiving oxygen containing gas; operating the AMFC at an operation temperature of above 80° C.; providing the oxygen containing gas; to a cathode of the AMFC at a pressure above the equilibrium vapor pressure of water at the operation temperature; maintaining the pressure during the operation of the AMFC as to maintain water in substantially liquid phase near the cathode; and providing the ammonia to an anode of the AMFC.

Abstract: Some aspects of the invention may be directed to a catalyst layer for anodes of Alkaline Exchange Membrane Fuel Cells (AEMFC). Such catalyst layer may include catalyst nanoparticles and an ionomer. Each catalyst nanoparticle may include one or more nanoparticles of catalytically active metal supported on at least one nanoparticle of crystalline RuO2. The diameter of the at least one nanoparticle of the crystalline RuO2 may be about order of magnitude larger than the diameter of the one or more nanoparticles of catalytically active metal.

Abstract: The invention relates to a system and method of operating alkaline exchange membrane fuel cells in a bipolar configuration. The system (400) may include a first fuel cell (300A) and a second fuel cell (300B) adjacent to the first fuel cell. Each of the first and second fuel cells may include: a cathode configured to generate hydroxide ions from water, oxygen and electrons, an anode configured to generate water and electrons from the hydroxide ions and hydrogen received from a hydrogen source, and an alkaline exchange membrane configured to transfer the hydroxide ions from the cathode to the anode, and to transfer water from a vicinity of the anode to a vicinity of the cathode. The first fuel cell (300A) and a second fuel cell (300B) are connected by a porous bipolar plate (430A) positioned inbetween.