A combined cycle power generation system for an aircraft includes fuel cell and supercritical CO.sub.2 cycles. The fuel cell cycle includes a compressor and turbine disposed on a first shaft, a fuel cell in fluid communication with the compressor and a fuel source, and a combustor in fluid communication with the fuel cell and the turbine. The combustor is configured to combust partially spent fuel from the fuel cell and produce combustion exhaust gas for delivery to the turbine. The supercritical CO.sub.2 cycle includes a compressor and turbine disposed on a second shaft, a supercritical CO.sub.2 fluid circuit in thermal communication with the combustor and configured to deliver CO.sub.2 to the turbine and compressor, and a heat exchanger in thermal communication with the supercritical CO.sub.2 fluid circuit and a source of cooling fluid. A mechanical linkage is configured to transfer power from the second shaft to the first shaft.

A zinc iodine flow battery includes a positive end plate, a positive current collector, a negative current collector, a positive electrode with a flow frame, a membrane, a negative electrode with a flow frame, a negative end plate. The negative electrolyte is circulated between the negative storage tank and the negative cavity by pump. The negative pipe is provided with a branch pipe for the positive electrolyte circulation. The porous membrane between the positive and negative electrodes can realize the conduction of supporting electrolyte and prevent the diffusion of I3− to the negative electrolyte. In a duel-flow battery system, same electrolyte serves as both the positive electrolyte and the negative electrolyte, which is a mixed aqueous solution containing iodized and zinc salt. The membrane is porous membrane does not contain ion exchange group. Both the positive and negative electrolyte are neutral solutions.

A redox flow battery system with a redox flow battery includes a redox flow cell, and a supply/storage system external of the redox flow cell. The supply/storage system includes first and second electrolytes for circulation through the redox flow cell. At least the first electrolyte is a liquid electrolyte that has electrochemically active species with multiple, reversible oxidation states. A secondary cell is fluidly connected with the first electrolyte and is operable to monitor concentration of one or more of the electrochemically active species. The secondary cell includes a counter electrode, a working microelectrode, and an ionically conductive path formed by the first electrolyte between the counter electrode and the working microelectrode.

A refueling system for hydrogen fuel cell-powered aircraft is disclosed. The system includes a compressor to receive a source of low temperature, high pressure hydrogen gas and compress the low temperature, high pressure hydrogen gas into a higher temperature, higher pressure hydrogen gas. A compression chamber within the compressor to receive the higher temperature, higher pressure hydrogen gas from the compressor. A valve coupled with the compression chamber to reduce the pressure of the higher temperature, higher pressure hydrogen gas to a higher temperature, lower pressure hydrogen gas. A storage container on an aircraft to receive the higher temperature, lower pressure hydrogen gas via the pressure relief valve. A heat exchanger in thermal cooperation with the compression chamber, the heat exchanger configured to absorb heat from the compression chamber and convert the heat into storable energy.

An energy recovery assembly, fuel cell system and vehicle, with an electrolyzer configured to provide a fuel and an oxidant, a fuel cell configured to convert the fuel and an oxidant to electrical energy, a tank configured to store the fuel or the oxidant, and a conduction pathway connecting the tank to the electrolyzer and the fuel cell. The assembly also includes: an expansion machine disposed in the conduction pathway and configured to expand a fluid flowing through the expansion machine and to obtain mechanical energy; and a valve arrangement configured to put the pathway in a first mode in which the fuel or the oxidant is guided to the tank, or in a second mode in which the fuel cell or the oxidant is guided to the fuel cell, wherein the fuel or the oxidant in the first and second modes flows through the expansion machine.

The invention relates to a stack of electrochemical cells (10A, 10B), divided up into at least two groups (A, B), each cell comprising a distribution circuit for a reactive species, and each group of cells comprising a separate supply collector (2A; 2B). At least one cell (10B) comprises a homogenization compartment (60B) comprising: a plurality of longitudinal conduits (61B) designed to receive the flow of the reactive species coming from the supply collector (2B) of the corresponding group and to distribute it over the inlet (51B) of the distribution circuit for the cell; and, a transverse conduit (62B) for homogenization connecting the longitudinal conduits (61B) to one another in a fluid sense.

The invention relates to a media management plate (1) for a fuel cell assembly (5), a fuel cell system (10) comprising the media management plate and a fuel cell assembly, and a method of operating a fuel cell system (10) comprising a fuel cell assembly (5) and the media management plate (1). All lines for supplying and discharging the fuel cell media and all devices necessary for treating the fuel cell media are integrated in the media management plate (1). The media management plate (1) can be heated by means of coolant and is functional both when oriented vertically and horizontally.

A modular flow battery includes a battery stack container housing a plurality of redox flow battery stacks in fluid communication with at least one pair of electrolyte containers including an anolyte container for holding an anolyte and a catholyte container for holding a catholyte. Additional pairs of electrolyte containers can be connected to the battery stack container to increase an amount of energy that can be stored by the modular flow battery system. Respective housings enclosing each of the battery stack container and the electrolyte containers are configured for operation in a stacked configuration. In this manner, the energy storage capacity of the modular flow battery system can be further increased with substantially no increase in a lateral area occupied by the system.

A redox flow battery includes first and second cells. Each cell has electrodes and a separator layer arranged between the electrodes. A first circulation loop is fluidly connected with the first electrode of the first cell. A polysulfide electrolyte solution has a pH 11.5 or greater and is contained in the first recirculation loop. A second circulation loop is fluidly connected with the second electrode of the second cell. An iron electrolyte solution has a pH 3 or less and is contained in the second circulation loop. A third circulation loop is fluidly connected with the second electrode of the first cell and the first electrode of the second cell. An intermediator electrolyte solution is contained in the third circulation loop. The cells are operable to undergo reversible reactions to store input electrical energy upon charging and discharge the stored electrical energy upon discharging.

A pulse hydrogen supply system for a proton exchange membrane fuel cell is provided. The system comprises a fuel cell, a high-pressure hydrogen bottle, a first pressure relief valve, an ejector, a steam-water separator, a first pressure control valve, a first pressure sensor, a high-pressure vessel, a first electromagnetic valve, a low-pressure vessel, a diaphragm pump, and a second electromagnetic valve. The high-pressure hydrogen bottle, the first pressure relief valve, the first pressure control valve, the ejector and the first pressure sensor are sequentially arranged on a gas inlet pipeline; the high-pressure vessel and the first electromagnetic valve are sequentially arranged on a branch pipeline; the second electromagnetic valve, the low-pressure vessel and the diaphragm pump are sequentially arranged on a first output loop; and the first output pipeline and the gas inlet pipeline form a loop.