The fuel cell (100) includes an oxidant flow plate (212), an adjacent cathode substrate layer (216) having a cathode catalyst (222), a matrix (224) for retaining a liquid electrolyte (230), wherein the matrix (224) is secured adjacent and between the cathode catalyst (222) and an anode catalyst (232). A first anode substrate (102) is secured adjacent the anode catalyst (232), and at least a second duplicate anode substrate layer (108) is secured adjacent the first anode substrate layer (102) for providing greater pore volume for storage of the liquid electrolyte (230) and to limit obstruction of the pore volume of the anode substrates (102, 108). The duplicate anode substrate layer (108) may be partially filled with the liquid electrolyte (230) at the beginning of life of the fuel cell (100).

An assembled battery includes a plurality of air cells arranged in a horizontal direction and a plurality of connection flow paths. Each air cell includes a storage portion between a positive electrode and a metal negative electrode to store an electrolysis solution. The storage portions of the respective adjacent air cells communicate with each other by the respective connection flow paths. An insulation fluid for electrically insulating the electrolysis solution in the respective adjacent air cells is sealed in the respective connection flow paths.

The present disclosure relate to a method for preparing a cathode electrolyte for redox flow batteries including the steps of: forming a first cathode electrolyte by reducing vanadium pentoxide (V.sub.2O.sub.5) in an acidic solution in the presence of a specific reducing compound; forming a second cathode electrolyte by reducing vanadium pentoxide (V.sub.2O.sub.5) in an acidic solution in the presence of a linear or branched aliphatic alcohol having 2 to 10 carbon atoms; and mixing the first cathode electrolyte and the second cathode electrolyte, and to a redox flow battery including the cathode electrolyte obtained by the preparation method.

There is provided a frame body used for a cell of a redox flow battery, that can improve heat dissipation of an electrolyte in a slit while reducing a shunt current loss through the electrolyte, and can also suppress strain caused at a slit formation portion. It is a frame body used for a cell of a redox flow battery, comprising: an opening formed inside the frame body; a manifold allowing an electrolyte to pass therethrough; and a slit which connects the manifold and the opening and forms a channel of the electrolyte between the manifold and the opening, the slit having at least one bent portion, the at least one bent portion having a radius of curvature of 2.0 mm or more and 200 mm or less.

A flow battery according to one aspect of the present disclosure includes: a first liquid containing dissolved therein a charge mediator and a discharge mediator; a first electrode immersed in the first liquid; and a first active material immersed in the first liquid. The equilibrium potential of the charge mediator is lower than the equilibrium potential of the first active material, and the equilibrium potential of the discharge mediator is higher than the equilibrium potential of the first active material.

A power supply battery and a power supply system for high-speed maglev trains are disclosed. The power supply battery comprises: an electrolyte tank, a plurality of liquid flow pumps, and a plurality of aluminum-air battery reactors. The plurality of aluminum-air battery reactors are sequentially connected in series. The electrolyte tank comprises a plurality of elongate electrolyte grooves. One liquid flow pump corresponds to one aluminum-air battery reactor and one electrolyte groove.

Embodiments of the invention relate to an open metal-air fuel cell system capable of uninterrupted supply power, which relates to the field of metal-air fuel cell stacks and comprises a sensing subsystem, a controller, a circulating filtration subsystem, an electrolyte solution tank and several open metal-air fuel cell units. Open metal-air fuel cell units are sequentially arranged within the electrolyte solution tank, and each open metal-air fuel cell unit is connected with each other in parallel. An air electrode of the open metal-air fuel cell unit has a tank structure, and the trough structure has a concave surface upwards. The sensing subsystem is arranged within the electrolyte tank. The electrolyte solution tank is connected with a circulating filtration subsystem. The controller is used for controlling a circulating flow of the circulating filtration subsystem depending on electrolyte solution temperature information collected by the sensing subsystem.

An elevated target amount of electrolyte is used to initially fill a molten carbonate fuel cell that is operated under carbon capture conditions. The increased target electrolyte fill level can be achieved in part by adding additional electrolyte to the cathode collector prior to start of operation. The increased target electrolyte fill level can provide improved fuel cell performance and lifetime when operating a molten carbonate fuel cell at high current density with a low-CO.sub.2 content cathode input stream and/or when operating a molten carbonate fuel cell at high CO.sub.2 utilization.

Devices and methods for managing the state of health of an electrolyte in redox flow batteries (RFB) efficiently are described. A diffusion cell is added to the RFB which controls one or more properties of the electrolytes using the diffusion of protons through a proton exchange membrane. The diffusion cell can resemble an electrochemical cell in that there are two fluid chambers divided by a proton conducting membrane. Anolyte flows through one side of the device where it contacts the proton conducting membrane, and catholyte flows through the second side of the device where it contacts the other face of the proton conducting membrane. The concentration gradient of protons from high concentration in the catholyte to low concentration in the anolyte is the driving force for proton diffusion, rather than electromotive force, which greatly simplifies the design and operation.

A method for replenishing an electrolyte of a molten carbonate fuel cell stack includes: preparing an electrolyte colloidal solution containing 10% to 20% of the electrolyte and having a viscosity of 200 to 800 Pa.Math.s; replenishing the electrolyte of the cell stack using the electrolyte colloidal solution prepared in step 1 to allow the electrolyte to adhere to an electrode and an internal channel of the cell stack; discharging excess electrolyte colloidal solution in the cell stack; and drying and discharging water or an organic solvent in the cell stack under an inert gas condition to complete replenishment of the electrolyte of the cell stack, and performing a discharge performance test.