A system and method for operating a fuel-cell system, which is attached to at least one further component via a cooling and/or lubricating circuit. A water-based, oil-free coolant and lubricant is used, and a flushing procedure for the fuel cell is initiated when a contamination of the fuel cell by the water-based, oil-free coolant and lubricant is detected.

A fuel cell includes: a membrane electrode assembly including an electrolyte membrane, catalyst layers stacked on both sides of the electrolyte membrane, and two or more porous bodies having different moduli of elasticity and provided on a surface of one of the catalyst layers; a separator defining a gas flow passage between the separator and the membrane electrode assembly; and a frame body surrounding an outer periphery of the electrolyte membrane. A porous body adjacent to the separator out of the two or more porous bodies includes an outer edge portion including an outer extending portion extending to overlap with the frame body. An elastic body is provided between the outer extending portion and the frame body.

A modular fuel cell includes a membrane electrode assembly interposed between a pair of bipolar plates, and the membrane electrode assembly has a total active area measured in an x-y plane that is generally perpendicular to the z-axis. Each bipolar plate includes a plurality of common passages extending generally parallel to the z-axis. The total active area of the membrane electrode assembly includes a plurality of base active areas arranged co-planar in the x-y plane along an x-axis.

A modular fuel cell includes a membrane electrode assembly interposed between a pair of bipolar plates, and the membrane electrode assembly has a total active area measured in an x-y plane that is generally perpendicular to the z-axis. Each bipolar plate includes a plurality of common passages extending generally parallel to the z-axis. The total active area of the membrane electrode assembly includes a plurality of base active areas arranged co-planar in the x-y plane along an x-axis.

A separator that is used for a fuel cell includes: a separator center area that is arranged to face a power generation area of the membrane electrode assembly; an outer peripheral portion that is extended from the separator center area to outer periphery; a first manifold hole and a second manifold hole that are provided in the outer peripheral portion; a fluid flow path that is arranged to extend from the first manifold hole through the separator center area to the second manifold hole; and a gasket that is provided on the outer peripheral portion to surround an area of the fluid flow path and outer circumferences of the first and second manifold holes. The gasket is divided into first gasket portions that are provided adjacent to ends of the separator center area and are extended along respective side edges at the ends, and second gasket portions that are provided to surround the outer circumferences of the first manifold hole and the second manifold hole, respectively. The first gasket portions have a larger width than a width of the second gasket portions.

An electrolyteless fuel cell system includes an anode; a cathode; an electrical grid between the anode and cathode; an anode side grid bias electrode; a cathode side grid bias electrode; and an electrical grid power supply, wherein the electrical grid is biased negative with respect to the anode through the anode side grid bias electrode and the electrical grid power supply, or wherein the electrical grid is biased positive with respect to the cathode through the cathode side grid bias electrode and the electrical grid power supply.

An electrolyteless fuel cell system includes an anode; a cathode; an electrical grid between the anode and cathode; an anode side grid bias electrode; a cathode side grid bias electrode; and an electrical grid power supply, wherein the electrical grid is biased negative with respect to the anode through the anode side grid bias electrode and the electrical grid power supply, or wherein the electrical grid is biased positive with respect to the cathode through the cathode side grid bias electrode and the electrical grid power supply.

A bipolar fuel cell plate (300) for use in a fuel cell comprising a plurality of flow field channels (704) and a coolant distribution structure (708) formed as part of the fluid flow field plate. The coolant distribution structure is configured to direct coolant droplets (701) into the flow field channels. The coolant distribution structure comprises one or more elements (710) associated with one or more flow field channels, the elements having a first surface (712) for receiving a coolant droplet and a second surface (714) having a shape that defines a coolant droplet detachment region for directing a coolant droplet into the associated field flow channel.

Systems and methods for sintering and conditioning fuel cell stacks utilizing channel guides, baffles, and internal compression systems are provided. Sintering and conditioning may be performed utilizing a fuel cell column cartridge assembly and fuel cell stacks may be sintered and conditioned at the system level during the same annealing cycle on the same support.

[Problem to be Solved] To provide a vanadium active material solution which has a vanadium active material concentration of 2.5 M or more in a sulfuric acid solution including a dispersoid (suspensible material), can stably maintain high energy density based on the concentration, and can respond also to fast charge and discharge, and to provide a vanadium redox battery using the active material solution.

[Solution] The above problem is solved by a vanadium active material solution comprising a vanadium compound, which is an active material, as a solute and a dispersoid, wherein the total concentration of vanadium is 2.5 M or more. Here, in a negative electrolyte, the vanadium compound comprises one or both of bivalent and trivalent vanadium. In a positive electrolyte, the vanadium compound comprises one or both of quadrivalent and pentavalent vanadium. In an active material solution, the vanadium compound comprises one or both of trivalent and quadrivalent vanadium. The average diameter of the dispersoid is in the range of 1 nm or more and 100 μm or less.