Disclosed are an electrode for gas generation, a method of preparing the electrode, and a device including the electrode for gas generation. The electrode includes a gas generating electrode layer and a three-dimensional (3D) super-aerophobic layer formed on at least one portion of the gas generating electrode layer and including porous hydrogel.

An anion exchange polymer includes aryl ether linkage free polyarylenes having aromatic/polyaromatic rings in polymer backbone and a tethered alkyl quaternary ammonium hydroxide side groups. This anion exchange polymer may be utilized in an anion exchange process and may be made into a thin anion transfer membrane. An ion transfer membrane may be mechanically reinforced having one or more layers of functional polymer based on a terphenyl backbone with quaternary ammonium functional groups and an inert porous scaffold material for reinforcement. An anion exchange membrane may have multilayers of anion exchange polymers which each containing varying types of backbones, varying degrees of functionalization, or varying functional groups to reduce ammonia crossover through the membrane.

Methods are described for treating aqueous solutions, including wastewater, to remove nitrogen-containing compounds using electrochemical processes. The method may be conducted electrolytically under an applied voltage or using endogenous current in a fuel cell arrangement. In some embodiments, energy is reclaimed in the form of hydrogen, methane, and other hydrocarbons or organic molecules. Microorganisms may be used as the catalyst for oxidation of the nitrogen-containing compound and/or reduction of hydrogen ions, carbon dioxide, or bicarbonate. Anaerobic or low-oxygen conditions may be used in the zone.

Aircraft systems including a pressurized fuel tank containing a pressurized fuel, a turbo expander configured to receive the pressurized fuel from the fuel tank, the turbo expander configured to decrease a pressure of the pressurized fuel to generate low pressure fuel having pressure less than the pressurized fuel, a fuel-to-air heat exchanger configured to receive the low pressure fuel from the turbo expander as a first working fluid and air as a second working fluid, the heat exchanger configured to cool the air and warm the fuel, an aircraft cabin configured to receive the cooled air, and a fuel consumption system configured to consume the fuel to generate power.

Various designs and configurations of and methods of operating fuel cell units, fuel cell systems and combined heat and power systems are provided that permit efficient thermal management of such units and systems to improve their operation.

A fuel cell system comprising an anode compartment which comprises an anode having a copper catalyst layer, a cathode configured as an air cathode and a separator interposed between said anode and said cathode, operable by an amine-derived fuel and oxygen (or air) is disclosed. Further disclosed are fuel cell systems comprising an anode compartment which comprises an anode having a copper catalyst layer, a cathode and a separator interposed between said anode and said cathode, which are operable by a mixture of two types of amine-derived compounds (e.g., ammonia borane, hydrazine and derivatives thereof). Also disclosed are methods of producing electric energy by, and electric-consuming devices containing and operable by, the disclosed fuel cell systems.

Thermally regenerative ammonia-based battery systems and methods of their use to produce electricity are provided according to aspects described herein in which ammonia is added into an anolyte to charge the battery, producing potential between the electrodes. At the anode, metal corrosion occurs in the ammonia solution to form an ammine complex of the corresponding metal, while reduction of the same metal occurs at the cathode. After the discharge of electrical power produced, ammonia is separated from the anolyte which changes the former anolyte to catholyte, and previous anode to cathode by deposition of the metal. When ammonia is added to the former catholyte to make it as anolyte, the previous cathode becomes the anode. This alternating corrosion/deposition cycle allows the metal of the electrodes to be maintained in closed-loop cycles, and waste heat energy is converted to electricity by regeneration of ammonia, such as by distillation.

Stable solutions comprising high concentrations of charged coordination complexes, including iron hexacyanides are described, as are methods of preparing and using same in chemical energy storage systems, including flow battery systems. The use of these compositions allows energy storage densities at levels unavailable by other iron hexacyanide systems.

A fuel cell capable of achieving excellent power output, which comprises a non-catalytic anode electrode and in which a reductant is used as a fuel, is provided. The fuel cell of the present invention comprises an anode electrode, a cathode electrode, and a membrane having ion conductivity that is disposed between the anode electrode and the cathode electrode, in which a reducing fuel in the anode electrode is oxidized in the presence of a heterocyclic compound containing nitrogen and carbon atoms and having 5- or 6-membered ring.

A method is disclosed for nitrogen recovery from an ammonium including fluid and a bio-electrochemical system for the same. In an embodiment, the method includes providing an anode compartment including an anode; providing a cathode compartment including a cathode, wherein the compartments are separated by at least one ion exchange membrane; providing the ammonium comprising fluid in the anode compartment and a second fluid in the cathode compartment; applying a voltage between the anode and the cathode; and extracting nitrogen from the cathode compartment.