A fuel cell system with reduced leakage and a method of assembling a fuel cell system. Bipolar plates within the system include reactant channels and coolant channels that are fluidly coupled to inlet and outlet flowpaths, all of which are formed within a coolant-engaging or reactant-engaging surface of the plate. One or more seals are also formed on the fluid-engaging surface to help reduce leakage by maintaining fluid isolation of the reactants and coolant as they flow through their respective channels and flowpaths that are defined between adjacently-placed plates. The seal—with its combination of in-plane and out-of-plane dimensions—forms a substantially hollow volume, into which a plug is placed to reduce the tendency of the seal to form a shunted flow of the coolant or reactant around the intended active area of the plate. A fluid port intersection is integrally formed with the seal and is formed to be fluidly cooperative with the volume, and is capable of accepting the introduction of a fluent precursor of the plug material such that upon curing, the precursor material forms a substantially rigid insert that continuously fills both the volume and intersection, thereby increasing the resistance of the plug to movement and the seal to shunted flow. In one form, the geometry of the fluent material injection site is such that it promotes plug anchoring within its intended location, while also providing a manufacturing aid to visually inspect for plug installation, as well as to serve as a bipolar plate stacking alignment locator and verification.

A structure of a fuel cell includes a sub-gasket coupled to both sides of a membrane electrode assembly; a plurality of gaskets protruding from a separator to form a flow space between the sub-gasket and the separator and supporting the sub-gasket; and a supporting member coupled to the sub-gasket at a position corresponding to the flow space, the supporting member preventing the sub-gasket from being deformed and being formed in a flat shape.

An example fuel cell stack component includes a metallic layer applied to the component and an oxide layer applied to the metallic layer. The oxide layer includes a chemical component that is not in the metallic layer.

An example fuel cell stack component includes a metallic layer applied to the component and an oxide layer applied to the metallic layer. The oxide layer includes a chemical component that is not in the metallic layer.

A unit cell for a fuel cell includes an electricity-generating assembly (EGA) in which a gas diffusion layer (GDL) is laminated on each of both sides of a membrane electrode assembly (MEA). The unit cell has a first separator and a second separator disposed on an outside of the EGA and a reaction surface is formed on each of the first and second separators through which a reactive gas flows. A cooling surface is formed on each of the first and second separators opposite the reaction surfaces and through which cooling water flows. A reaction surface gasket is formed on the reaction surface of the first separator, wrapping and fixing a top and bottom of the EGA, and forming an airtight line with the second separator. A cooling surface gasket is formed on the cooling surface of the first separator and forms an airtight line with a second separator of another unit cell disposed adjacent to the unit cell.

A separator unit for a fuel cell includes a separator including a reaction region, a plurality of manifolds formed on each side of the reaction region, and a reaction surface and a cooling surface formed on each surface thereof, a reaction surface internal gasket forming a reaction surface internal airtight line, and a reaction surface external gasket forming a reaction surface external airtight line, wherein at least one cut portion formed by removing the reaction surface external gasket is formed in the reaction surface external airtight line surrounding at least one of the plurality of manifolds.

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.

A single cell C includes a membrane electrode assembly M in which an electrolyte membrane 1 is interposed between a pair of electrode layers 2, 3, and a pair of separators 4 that form gas channels C between the pair of separators 4 and the membrane electrode assembly M, wherein the electrode layers 2, 3 include first gas diffusion layers 2B, 3B of a porous material disposed at the side facing the electrolyte membrane 1 and second gas diffusion layers 2C, 3C that are composed of a metal porous body having arrayed many holes K, and a part of the first gas diffusion layers 2B, 3B penetrates the holes K of the second gas diffusion layers 2C, 3C to form protrusions T. Accordingly, the surface of the electrode layers 2, 3 has a fine uneven structure. As a result, an improvement in liquid water discharging function and an improvement in power generating function were achieved at the same time.

A single cell C includes a membrane electrode assembly M in which an electrolyte membrane 1 is interposed between a pair of electrode layers 2, 3, and a pair of separators 4 that form gas channels C between the pair of separators 4 and the membrane electrode assembly M, wherein the electrode layers 2, 3 include first gas diffusion layers 2B, 3B of a porous material disposed at the side facing the electrolyte membrane 1 and second gas diffusion layers 2C, 3C that are composed of a metal porous body having arrayed many holes K, and a part of the first gas diffusion layers 2B, 3B penetrates the holes K of the second gas diffusion layers 2C, 3C to form protrusions T. Accordingly, the surface of the electrode layers 2, 3 has a fine uneven structure. As a result, an improvement in liquid water discharging function and an improvement in power generating function were achieved at the same time.

Disclosed is a jig for surface treatment of a separator which is used to partially form a coating layer on a surface of the separator in which each land and each channel are alternately and repeatedly formed on one side and the other side according to a concavo-convex shape. In particular, the jig includes: a first jig which has a first plate part disposed on the one side of the separator and first mask parts protruding from the first plate part to cover an inner surface of one side-channel; and a second jig that has a second plate part disposed on the other side of the separator and second mask parts protruding from the second plate part to cover an inner surface of the other side-channel.