The present disclosure relates to a hydrogen filling system that includes a receptacle that is provided in a fuel cell electric vehicle and to which a fueling nozzle that dispenses hydrogen is connected, a manifold connected with a hydrogen tank provided in the fuel cell electric vehicle, a hydrogen filling line that connects the receptacle and the manifold, a hydrogen supply line that connects a fuel cell stack provided in the fuel cell electric vehicle and the manifold, and a buffer line that is connected to the hydrogen supply line and that heats the receptacle using heat of compression by the hydrogen that is supplied into the hydrogen supply line during filling of the hydrogen tank with the hydrogen. The present disclosure may obtain advantageous effects of suppressing freezing of the receptacle and improving safety and reliability.

In various embodiments, components such as interconnects and/or endplates of a solid-state electrochemical device are coated with materials such as, for example, graphite, copper, aluminum, carbide ceramics, nitride ceramics, conversion coatings, or aluminum intermetallics.

In various embodiments, components of a solid oxide fuel cell device such as interconnect plates, seals, and/or endplates may be composed of materials including aluminum, copper, and/or graphite.

The nitrogen battery of the present disclosure includes a positive electrode that uses nitrogen as a positive electrode active material, a negative electrode, and an ion conducting medium that contains a silane compound and conducts alkali metal ions.

A method of controlling a hydrogen partial pressure can be carried out in a fuel cell system including a stack having a hydrogen electrode and an air electrode. The method includes: determining a point of time to purge the hydrogen electrode using a hydrogen concentration at an outlet of the hydrogen electrode or an accumulated amount of charge generated in the stack; and setting a target supply pressure of hydrogen supplied to the stack, in which the target hydrogen supply pressure is set in consideration of a hydrogen pressure and a partial pressure of nitrogen resulting from crossover in the stack.

The present disclosure relates to a method of generating energy. This method involves providing a fuel cell comprising anode and cathode electrodes; a separator positioned between the anode and cathode electrodes; and anode and cathode catalysts. The anode catalyst comprises (i) a low-loading of platinum group metals (PGMs) supported on a Group 4-6 transition metal carbide (TMC) or nitride (TMN); (ii) an alloy or physical mixture comprising a Group 10 transition metal selected from Pt, Pd, and Ni and one or more of the following elements: Pt, Pd, Ni, Ir, Rh, Ru, Fe, Re, Sn, W, Mo, Ta, and Nb; or (iii) mixtures thereof. According to the method, a liquid anode fuel comprising one or more hydrazide compounds is added to the fuel cell to generate energy from the liquid anode fuel. Also disclosed is a fuel cell for generating energy from a liquid anode fuel comprising one or more hydrazide compounds.

A method of controlling hydrogen concentration of a fuel cell includes calculating hydrogen or nitrogen concentration of gas stored in a fuel tank; estimating hydrogen or nitrogen concentration at an anode of the fuel cell based on the calculated hydrogen or nitrogen concentration of the gas; and controlling a hydrogen supply unit based on the estimated hydrogen or nitrogen concentration at the anode such that the hydrogen or nitrogen concentration at the anode follows desired hydrogen concentration or desired nitrogen concentration.

The present invention relates to methods and apparatuses for determining the ratio of oxidized and reduced forms of a redox couple in solution, each method comprising: contacting first and second stationary working electrodes and first and second counter electrode to the solution; applying a first potential at the first stationary working electrode and a second potential at the second stationary working electrode relative to the respective counter electrodes and measuring first and second constant currents for the first and second stationary working electrodes, respectively; wherein the first and second constant currents have opposite signs and the ratio of the absolute values of the first and second constant currents reflects the ratio of the oxidized and reduced forms of the redox couple in solution. When used in the context of monitoring/controlling electrochemical cells, additional embodiments include those further comprising oxidizing or reducing the solution.

A combination of redox active compounds is useful in connection with a rechargeable battery and includes a first redox active compound having a first solubility, and a second redox active compound having a second solubility, wherein the combination has a third solubility that is greater than one or both of the first solubility and the second solubility.

The present invention relates to methods and apparatuses for determining the ratio of oxidized and reduced forms of a redox couple in solution, each method comprising: (a) contacting a first stationary working electrode and a first counter electrode to the solution; (b) applying a first potential at the first working electrode and measuring a first constant current; (c) applying a second potential at the first working electrode and measuring a second constant current; wherein the sign of the first and second currents are not the same; and wherein the ratio of the absolute values of the first and second currents reflects the ratio of the oxidized and reduced forms of the redox couple in solution. When used in the context of monitoring/controlling electrochemical cells, additional embodiments include those further comprising (d) oxidizing or reducing the solution, so as to alter the balance of the oxidized and reduced forms of the redox couple in solution, to a degree dependent on the ratio of the absolute values of the first and second currents. These embodiments may be used in the context of maintaining an electrochemical cell, stack, or system.