Abstract: A reversible fuel cell includes a positive electrode containing manganese dioxide, a negative electrode containing a hydrogen storage material, a separator disposed between the positive electrode and the negative electrode, and an electrolyte. Each of the negative electrode and the positive electrode is an electrode for power generation and is also an electrode that applies electrolysis to the electrolyte using electric current to be fed from the outside. This cell is capable of storing electric energy to be supplied at the time of overcharge by converting the electric energy into gas, and is also capable of reconverting the gas into electric energy in order to utilize the electric energy. Accordingly, there are provided a reversible fuel cell and a reversible fuel cell system each of which is excellent in energy utilization efficiency, energy density and load following capability.

Abstract: A ship includes: a high-pressure injection engine using fuel gas as fuel to obtain a propulsion power of the ship; a generator engine using fuel gas as fuel to generate electricity; a motor generating a power by using the electricity generated from the generator engine; a propulsion propelling the ship; a main clutch connecting the high-pressure injection engine to the propulsion; an auxiliary clutch connecting the gear box to the propulsion; and a gear box disposed in a front side of the propulsion and power-connected to the main clutch and the auxiliary clutch. The high-pressure injection engine and the motor are selectively power-connected to the propulsion to obtain the propulsion power of the ship.

Abstract: A metal-halogen flow battery system includes a stack of flow cells, an electrolyte reservoir and one or more of a concentrated halogen return line fluidly connecting the stack to the reservoir, a venturi, a mixer, a concentrated halogen pump, or a concentrated halogen line heater.

Abstract: Embodiments of an electrochemical flow cell stack are disclosed. A plurality of frame layers may each have a peripheral gasket channel configured to receive a gasket material. The gasket channel may surround a recessed area having a size and a structure configured to receive an insert layer. Each of the plurality of frame layers may include at least one void area defining a first half-cell chamber of a flow cell. A plurality of insert layers may each be nested within a corresponding frame layers. Each insert layer may include at least one void area defining a second half-cell chamber of the flow cell. A flow cell may be formed by one of the plurality of frame layers and one of the plurality of insert layers.

Abstract: An electrolyte system for a hybrid flow battery has a manganese based anolyte and a manganese based catholyte.

Abstract: Embodiments of redox flow battery rebalancing systems include a system for reacting an unbalanced flow battery electrolyte with a rebalance electrolyte in a first reaction cell. In some embodiments, the rebalance electrolyte may contain ferrous iron (Fe2+) which may be oxidized to ferric iron (Fe3+) in the first reaction cell. The reducing ability of the rebalance reactant may be restored in a second rebalance cell that is configured to reduce the ferric iron in the rebalance electrolyte back into ferrous iron through a reaction with metallic iron.

Abstract: Disclosed is a flow battery pack with a monitoring system. The flow battery pack with a monitoring system comprises a battery pack device and a monitoring device. The battery pack device comprises a pole plate, and the pole plate is provided thereon with a measuring port. The monitoring device comprises a measuring probe, and the measuring probe extends to the interior of the battery pack device and is arranged corresponding to the measuring port on the pole plate. The monitoring device is used for monitoring the flow pressure and temperature at the measuring port. According to the technical solution of the present disclosure, a monitoring device is introduced into the interior of a flow battery pack, and the real values of correlative parameters of the interior of the battery pack and the distribution status thereof can be obtained through the monitoring device.

Abstract: The invention discloses general apparatus and methods for electrochemical energy conversion and storage via a membraneless laminar flow battery. In a preferred embodiment, the battery includes a flow-through porous anode for receiving a fuel and a porous electrolyte channel for transporting an electrolyte adjacent to the porous anode; a flow-through porous cathode is provided for transporting an oxidant; and a porous dispersion blocker is disposed between the electrolyte channel and the porous cathode, which inhibits convective mixing while allowing molecular diffusion and mean flow. Pore structure properties are selected for tuning convective dispersion, conductivity or other macroscopic properties. Specific materials, reactants, fabrication methods, and operation methods are disclosed to achieve stable charge/discharge cycles and to optimize power density and energy density.

Abstract: The disclosure is directed at a method and apparatus for controlling fuel cell operating conditions. The apparatus includes a set of sensors for monitoring the fuel cell operating conditions and a processing unit, in communication with the set of sensors for determining when the fuel cell operating conditions are outside of an acceptable range. When it is determined that the fuel cell operating conditions are outside of the acceptable range, an electrolyzer is activated to electrolyze waste liquid water or water vapor to assist in controlling the fuel cell operating conditions.

Abstract: A secondary battery fuel system comprises: a fuel generation member that generates a fuel by a chemical reaction and is renewable by a reverse reaction of the chemical reaction; a fuel cell; a gas circulation line that circulates a gas between the fuel generation member and the fuel cell; an external fuel gas supply line that supplies a fuel gas output from an external gas supply source to the gas circulation line; a gas exhaust line that exhausts the gas from the gas circulation line; first and second open-close parts; and a control part. When switching from power generation employing external fuel gas to either a power generation operation employing circulation gas or a charging operation which regenerates the fuel generation member, the control part closes the gas exhaust line with the second open-close part, and then closes the external fuel gas supply line with the first open-close part.

Abstract: A self contained energy generating system that comprises a galvanic battery and a power distribution system. The energy generating system is used to purify water by using a reverse osmosis device that draws in a source of water and transfers electrolytes to the galvanic battery. Upon contact with the electrolyte, the galvanic battery produces energy by an oxidation-reduction reaction of the cathode and anode and transfers energy to the power distribution system, which in turn provides power to the osmosis device. Additionally, the system includes a hydrogen fuel cell to increase the amount of energy generated and a power storage device for storing excess energy generated. The system also includes a controller which is configured to regulate the overall operation of the system.

Abstract: Disclosed is a fuel cell apparatus which can continue stable performance, can generate an electric power for a long period, and has a long service life. The fuel cell apparatus comprises: a fuel cell body comprising a power generation unit which can generate an electric power through the reaction between hydrogen and oxygen and a hydrogen generation member which can generate hydrogen through the reaction with water produced upon the generation of the electric power and can supply hydrogen generated to the power generation unit; and a reduction control unit which can control so as to reduce the hydrogen generation member that has been oxidized through the reaction with the produced water.

Abstract: A fuel cell system, provided with: a fuel-generating material which generates a fuel by a chemical reaction and which can be regenerated by a reverse reaction of the aforementioned chemical reaction; a first fuel cell in which gas is circulated with respect to the fuel-generating material; and a second fuel cell for generating power using a fuel gas introduced from an external gas supply source. The amount of heat generated in the second fuel cell performing a power generation operation is transmitted to the first fuel cell preforming an electrolysis operation.

Abstract: This secondary cell-type fuel cell system is provided with: a fuel generation unit which by a chemical reaction generates fuel that is a reducing gas, and which can be regenerated by means of the reverse reaction of said chemical reaction; a power generation and electrolysis unit having a power generation function for generating power using the reducing gas, and an electrolysis function for electrolyzing an oxidized gas which, a product of the aforementioned reverse reaction, is supplied from the fuel generation unit during regeneration of the fuel generation unit; a circulation unit which forcibly circulates a gas containing the reducing gas and/or the oxidized gas between the fuel generation unit and the power generation and electrolysis unit; and a control unit for controlling the circulation unit. Further, the control unit controls the flow rate of the gas circulated by the circulation unit differently during power generation and during charge operations.

Abstract: A method and system for storing and/or discharging electrical energy that has a cost, which method includes steps of: (a) providing a flow battery system comprising at least one flow battery cell and a controller; (b) operating the flow battery cell at a power density having a first value; and (c) changing the power density at which the flow battery cell is operated from the first value to a second value as a function of the cost of the electrical energy, wherein the power density is changed using the controller, and wherein the second value is different than the first value.

Abstract: Disclosed herein is a redox flow battery, and more particularly, a cell frame channel design capable of efficiently distributing an electrolyte. The present invention provides a cell frame of a redox flow battery providing an electrolyte to an electrode, the cell frame of a redox flow battery including: an electrolyte inlet part and an electrolyte outlet part disposed at both side surfaces of the electrode, respectively; a distribution channel connected to the electrolyte inlet part and dividing the electrolyte into a plurality of channels; a buffer channel formed in a shape in which the buffer channel is connected to an end of each distribution channel and a channel width thereof is increased toward the electrode; a mixing zone formed between the buffer channel and the electrode to mix electrolytes flowed from the buffer channels with each other.

Abstract: The present invention provides a non-aqueous redox flow battery comprising a negative electrode immersed in a non-aqueous liquid negative electrolyte, a positive electrode immersed in a non-aqueous liquid positive electrolyte, and a cation-permeable separator (e.g., a porous membrane, film, sheet, or panel) between the negative electrolyte from the positive electrolyte. During charging and discharging, the electrolytes are circulated over their respective electrodes. The electrolytes each comprise an electrolyte salt (e.g., a lithium or sodium salt), a transition-metal free redox reactant, and optionally an electrochemically stable organic solvent. Each redox reactant is selected from an organic compound comprising a conjugated unsaturated moiety, a boron cluster compound, and a combination thereof. The organic redox reactant of the positive electrolyte comprises a tetrafluorohydroquinone ether compound or a tetrafluorocatechol ether compound.

Abstract: This redox flow secondary battery has an electrolyte tank (6) containing: a positive electrode cell chamber (2) containing a positive electrode (1) comprising a carbon electrode; a negative electrode cell chamber (4) containing a negative electrode (3) comprising a carbon electrode; and an electrolyte membrane (5) as a barrier membrane that separates/isolates the positive electrode cell chamber (2) and the negative electrode cell chamber (4). The positive electrode cell chamber (2) contains a positive electrode electrolyte containing an active substance, the negative electrode cell chamber (4) contains a negative electrode electrolyte containing an active substance, and the redox flow secondary battery charges and discharges on the basis of the change in valency of the active substances in the electrolytes.

Abstract: A flow battery includes a positive electrode, a positive electrode electrolyte, a negative electrode, a negative electrode electrolyte, and a polymer electrolyte membrane interposed between the positive electrode and the negative electrode. The positive electrode electrolyte includes water and a first redox couple. The first redox couple includes a first organic compound which includes a first moiety in conjugation with a second moiety. The first organic compound is reduced during discharge while during charging the reduction product of the first organic compound is oxidized to the first organic compound. The negative electrode electrolyte includes water and a second redox couple. The second couple includes a second organic compound including a first moiety in conjugation with a second moiety. The reduction product of the second organic compound is oxidized to the second organic compound during discharge.

Abstract: This fuel generator is equipped with fine particles of a fuel-generating agent (1) that generates fuel by an oxidation reaction with an oxidizing gas and can be regenerated by a reduction reaction with a reducing gas, and a porous member (3). The fine particles of the fuel-generating agent (1) are dispersed and disposed in the interior of the porous member(3).

Abstract: An energy generating apparatus including water molecule separating device, water molecule recombining device, and water molecule recycling device, which generates various energy outputs by various means. The water separating device can be a type of machine of several designs which operates chemically and produces H2 and O2 from the water molecule. It is attached to a water recombining device of several designs which operates chemically and produces several forms of energy when recombining H2 and O2 into the water molecule. There is also a recycling device which is used to return the water molecule and its atoms to the beginning of the cycle which may or may not be used depending upon application.

Abstract: The invention relates to a carbon-free electrocatalyst for fuel cells, containing an electrically conductive substrate and a catalytically active species, wherein the conductive substrate is an inorganic, multi-component substrate material of the composition 0X1-0X2, in which 0X1 means an electrically non-conductive inorganic oxide having a specific surface area (BET) in the range of 50 to 400 mVg and 0X2 means a conductive oxide. The non-conductive inorganic oxide 0X1 is coated with the conductive oxide 0X2. The multi-component substrate preferably has a core/shell structure. The multi-component substrate material 0X1-0X2 has an electrical conductivity in the range>0.01 S/cm and is coated with catalytically active particles containing noble metal. The electrocatalysts produced therewith are used in electrochemical devices such as PEM fuel cells and exhibit high corrosion stability.

Abstract: A secondary battery type fuel cell system is provided with: a fuel cell unit which generates oxidation gas during power generation and has a fuel electrode, an oxidant electrode, and an electrolyte sandwiched between the fuel electrode and the oxidant electrode; and a fuel generation unit which generates fuel in the form of reducing gas by means of the chemical reaction with the oxidation gas and which can generate and regenerate the oxidation gas by means of the reverse reaction of the aforementioned chemical reaction. In a closed or hermetically-sealed space containing the fuel electrode and the fuel generation unit, the oxidation gas or the reducing gas is forcibly circulated between the fuel cell unit and the fuel generation unit, and the flow direction of the gas flowing along the surface of the fuel electrode is set to be the same during the power generation operation and the charging operation.

Abstract: An electrolysis apparatus comprises an electrolysis cell to electrolyze a first fluid to generate a product fluid. The electrolysis apparatus also comprises a fuel cell to electrolyze an electrolytic fluid and to heat a second fluid. The electrolysis apparatus also includes a fluid transfer arrangement to transfer the heated second fluid from the fuel cell to the electrolysis cell to provide heat to drive the electrolysis of the first fluid in the electrolysis cell.

Abstract: The present invention generally relates to storing energy in a form that is carbon neutral, storable and transportable, so that it can be used on demand. The present invention provides a process and system for using energy as available to produce carbon from carbon oxide, and then oxidizing the carbon to generate useful energy on demand, while effectively recycling the carbon, oxidant, and carbon oxide used in the process or system. In one embodiment, the present invention effectively stores renewable energy as carbon, transports the carbon, oxidizes the carbon to generate useful energy on demand and recycles the carbon as carbon dioxide. This invention may increase the utilization of renewable energy, especially for electrical power generation, while producing no net carbon dioxide or other air pollutants.

Abstract: Methods, systems, and devices are disclosed for fabricating and implementing multifunctional fuel cells. In one aspect, a multifunctional fuel cell device includes a first electrode and a second electrode separated by a distance and aligned substantially in parallel, a first conduit and a second conduit coupled to the first electrode and the second electrode, respectively, substantially perpendicular to the electrodes, and a fluid including an electrolyte, the fluid dispersed between the electrodes, in which an applied electric potential across the first and second conduits induces oppositely charged sides of the first and second electrodes to form a cathode and an anode side of each electrode, thereby extracting energy from the electrolyte and producing a chemical product.

Abstract: A fuel cell system includes a fuel cell stack, a heavy hydrocarbon fuel source, and a fractionator configured to separate light ends from heavy ends of a heavy hydrocarbon fuel provided from the heavy hydrocarbon fuel source.

Abstract: A method for operating a fuel cell system during an interruption includes identifying a load interruption in which an external load is partially or fully unable to draw electrical power from the fuel cell system. At least a first fuel cell column of the fuel cell system is operated in an electrolysis mode such that the first fuel cell column generates fuel during the load interruption. Power is provided to the first fuel cell column in the electrolysis mode from at least a second fuel cell column of the fuel cell system. The second fuel cell column is operating in a normal power generation operating mode.

Abstract: A method for producing electric power and regenerating an aqueous multi-electron oxidant (AMO) and a reducer in an energy storage cycle is provided. A discharge system includes a discharge unit, an acidification reactor, and a neutralization reactor. The acidification reactor converts an oxidant fluid including the AMO into an acidic oxidant fluid. The discharge unit generates electric power and a discharge fluid by transferring electrons from a positive electrode of an electrolyte-electrode assembly (EEA) to the AMO and from a reducer to a negative electrode of the EEA. The neutralization reactor neutralizes the discharge fluid to produce a neutral discharge fluid. The regeneration system splits an alkaline discharge fluid into a reducer and an intermediate oxidant in a splitting-disproportionation reactor and releases the reducer and a base, while producing the AMO by disproportionating the intermediate oxidant. The regenerated AMO and reducer are supplied to the discharge unit for power generation.

Abstract: The reservoirs 2 and 2? preliminarily contain liquid water, which is utilized as the water to be supplied to the polymer membrane. A vapor pressure of the water is set to a predetermined value in the reservoir by controlling the temperature of the reservoirs 2 and 2? individually. Pressure gauges 6 and 6? may be used for setting a vapor pressure of the water. The water which is gasified based on the set vapor pressure in the respective reservoir is supplied to the stack 10 along with oxygen from the reservoir 2, and with hydrogen from the reservoir 2?. This configuration makes it possible to adjust the amount of water contained in the polymer membrane and maintain the moisturization of the polymer membrane without external water supply.

Abstract: Methods for generating electric power and a discharge fluid from an oxidant and a reducer using a discharge system, and regenerating an oxidant and/or the reducer from the discharge fluid using a regeneration system are provided. A discharge unit of the discharge system generates electric power and the discharge fluid by transferring electrons from a positive electrode of a 5-layer electrolyte-electrode assembly (5EEA) to an aqueous multi-electron oxidant (AMO) and from a reducer to a negative electrode of the 5EEA. The regeneration system neutralizes the discharge fluid to produce a salt form of the discharge fluid. The regeneration system electrolyzes the salt form of the discharge fluid into an intermediate oxidant in an electrolysis-disproportionation reactor and releases the reducer, while producing the AMO by disproportionating the intermediate oxidant. The regeneration system converts a salt form of the AMO into an acid form of the AMO in an ion exchange reactor.

Abstract: The present invention provides a regenerative fuel cell comprising an anionic membrane capable of selectively passing anions, wherein the pH of the anolyte and/or catholyte is at least 10. The present invention also relates to a method of operating a regenerative fuel cell comprising an anionic membrane capable of selectively passing anions, wherein the pH of the anolyte and/or catholyte is at least 10.

Abstract: There is provided a method for the activation of a fuel cell. An exemplary method comprises operating the fuel cell entirely or partially at least briefly in an electrolysis regimen during galvanic operation.

Abstract: A closed loop energy storage system configured with a hydrogen tank, an oxygen tank, a fuel cell stack and an electrolyzer. A heat exchanger freeze-dries the hydrogen and oxygen prior to their storage in their respective tanks. The heat exchanger also uses excess fuel cell heat to preheat streams of hydrogen and oxygen coming from the tanks. Phase separators serve both to separate water from hydrogen and oxygen, and to store the water. A thermal management system encloses all the system components except the tanks. An airfoil-shaped shell covers the system, and the larger of the two tanks extends substantially across the shell at its point of greatest camber thickness. The tanks are composed of polymer liners integral with composite shells.

Abstract: An improved system of hardware and controls, known as a Hyper Hub, that absorbs electric power from any source, including hydropower, wind, solar, and other renewable energy resources, chemically stores the power in hydrogen-dense anhydrous ammonia, then reshapes the stored energy to the power grid with zero emissions by using anhydrous ammonia to fuel diesel-type, spark-ignited internal combustion, combustion turbine, fuel cell or other electric power generators, and for other purposes.

Abstract: In one embodiment, an electrical power storage system using hydrogen includes a power generation unit generating power using hydrogen and oxidant gas and an electrolysis unit electrolyzing steam. The electrical power storage system includes a hydrogen storage unit storing hydrogen generated by the electrolysis and supplying the hydrogen to the power generation unit during power generation, a high-temperature heat storage unit storing high temperature heat generated accompanying the power generation and supplying the heat to the electrolysis unit during the electrolysis, and a low-temperature heat storage unit storing low-temperature heat, which is exchanged in the high-temperature heat storage unit and generating with this heat the steam supplied to the electrolysis unit.

Abstract: Active metal fuel cells are provided. An active metal fuel cell has a renewable active metal (e.g., lithium) anode and a cathode structure that includes an electronically conductive component (e.g., a porous metal or alloy), an ionically conductive component (e.g., an electrolyte), and a fluid oxidant (e.g., air, water or a peroxide or other aqueous solution). The pairing of an active metal anode with a cathode oxidant in a fuel cell is enabled by an ionically conductive protective membrane on the surface of the anode facing the cathode.

Abstract: An electrochemical energy conversion and storage system comprises an electrochemical energy conversion device, in fluid communication with a source of an organic liquid carrier of hydrogen and an oxidant, for receiving, catalyzing and electrochemically oxidizing at least a portion of the hydrogen to generate electricity, a hydrogen depleted liquid, and water; and a vessel for receiving the hydrogen depleted liquid; wherein the organic liquid carrier of hydrogen comprises at least two secondary hydroxy groups is provided.

Abstract: This disclosure relates to electrochemical systems, e.g., a combination of an electrical energy source and an electrical energy storage system having a regenerative fuel cell system, that exhibit operational stability in harsh environments, e.g., both charging and discharging reactions in a regenerative fuel cell in the presence of an acid or a mixture of acids, or a halogen ion or a mixture of halogen ions. The electrochemical systems are capable of conducting both hydrogen evolution reactions (HERs) and hydrogen oxidation reactions (HORs) in the same system. The electrochemical systems have low cost, fast response time, and acceptable life and performance. This disclosure also relates to methods of operating the electrochemical systems containing a regenerative fuel cell system.

Abstract: A photoelectrochemical cell (100) includes: a semiconductor electrode (120) including a conductor (121), a first n-type semiconductor layer (122) having a nanotube array structure, and a second n-type semiconductor layer (123); a counter electrode (130) connected to the conductor (121); an electrolyte (140) in contact with the second n-type semiconductor layer (123) and the counter electrode (130); and a container (110) accommodating the semiconductor electrode (120), the counter electrode (130) and the electrolyte (140).

Abstract: A fuel cell system includes a solid oxide reversible fuel cell (SORFC) stack that is adapted to generate an exhaust stream containing hydrogen and water vapor from an outlet of the SORFC stack when the SORFC stack is operated in an electrolysis mode, a polymer electrolyte membrane (PEM) hydrogen pump that is adapted to separate at least a portion of the hydrogen contained in the exhaust stream, a first conduit that is adapted to provide the exhaust stream from the outlet of the SORFC stack into an inlet of the PEM hydrogen pump, and a second conduit that is adapted to provide at least a portion of remaining exhaust stream from an outlet of the PEM hydrogen pump into an inlet of the SORFC stack.

Abstract: An apparatus for recharging a fuel cell cartridge and methods for recharging a fuel cell cartridge are disclosed. An example recharging apparatus may include a housing having a fuel cell cartridge holder. A water reservoir may be disposed in the housing and may have water disposed therein. The recharging apparatus may also include an electrolysis chamber for converting water into hydrogen and oxygen. The electrolysis chamber may be in fluid communication with the water reservoir. The electrolysis chamber may include a hydrogen passage for passing hydrogen from the electrolysis chamber to the fuel cell cartridge holder. The recharging apparatus may further include a vacuum pump at least selectively in fluid communication with the fuel cell cartridge holder. In some instances, the vacuum pump may be used to evacuate residual hydrogen and/or other gases or materials from the fuel cell cartridge and/or determine if the fuel cell cartridge is leaky and requires replacement.

Abstract: Disclosed is a fuel cell apparatus which can continue stable performance, can generate an electric power for a long period, and has a long service life. The fuel cell apparatus comprises: a fuel cell body comprising a power generation unit which can generate an electric power through the reaction between hydrogen and oxygen and a hydrogen generation member which can generate hydrogen through the reaction with water produced upon the generation of the electric power and can supply hydrogen generated to the power generation unit; and a reduction control unit which can control so as to reduce the hydrogen generation member that has been oxidized through the reaction with the produced water.

Abstract: An electrochemical method for providing hydrogen using ammonia, ethanol, or combinations thereof, comprising: forming an anode comprising a layered electrocatalyst, the layered electrocatalyst comprising at least one active metal layer deposited on a carbon support; providing a cathode comprising a conductor; disposing a basic electrolyte between the anode and the cathode; disposing a fuel within the basic electrolyte; and applying a current to the anode causing the oxidation of the fuel, forming hydrogen at the cathode.

Abstract: High efficiency electricity generation processes and systems with substantially zero CO2 emissions are provided. A closed looping between the unit that generates gaseous fuel (H2, CO, etc) and the fuel cell anode side is formed. In certain embodiments, the heat and exhaust oxygen containing gas from the fuel cell cathode side are also utilized for the gaseous fuel generation. The systems for converting fuel may comprise reactors configured to conduct oxidation-reduction reactions. The resulting power generation efficiencies are improved due to the minimized steam consumption for the gaseous fuel production in the fuel cell anode loop as well as the strategic mass and energy integration schemes.

Abstract: The present invention generally relates to conducting materials such as mixed ionically and electrically conducting materials. A variety of materials, material compositions, materials with advantageous ratios of ionically and electrically conducting components, structures including such materials, and the like are provided in accordance with the invention. In one aspect, the invention relates to conducting ceramics for electrochemical systems and, in particular, to mixed ionically and electrically conducting ceramics which can be used, for example, for electrochemical systems and, in particular, to mixed ionically and electrically conducting ceramics which can be used, for example, for hydrogen gas generation from a gasified hydrocarbon stream. One aspect of the invention provides a material comprising a first phase comprising a ceramic ionic conductor, and a second phase comprising a ceramic electrical conductor.

Abstract: A closed loop energy storage system configured with a hydrogen tank, an oxygen tank, a fuel cell stack and an electrolyzer. A heat exchanger freeze-dries the hydrogen and oxygen prior to their storage in their respective tanks. The heat exchanger also uses excess fuel cell heat to preheat streams of hydrogen and oxygen coming from the tanks. Phase separators serve both to separate water from hydrogen and oxygen, and to store the water. A thermal management system encloses all the system components except the tanks. An airfoil-shaped shell covers the system, and the larger of the two tanks extends substantially across the shell at its point of greatest camber thickness. The tanks are composed of polymer liners integral with composite shells.

Abstract: A technique includes operating an electrochemical cell as a pump, including providing a current to the cell and providing a fuel flow to an anode chamber of the cell. The technique includes communicating an anode exhaust flow from the anode chamber to an oxidizer and controlling the current to regulate a temperature of the oxidizer.

Abstract: A technique includes operating a fuel cell, which produces an effluent flow. The technique includes routing the effluent flow through an electrochemical pump to extract fuel from the effluent flow and providing the extracted fuel to the fuel cell.

Abstract: The invention relates to a method of storing, transporting and supplying electrochemical energy, with storage and supply being physically separated.