A fuel cell stack includes a membrane electrode assembly and a bipolar plate. The bipolar plate has a corrugated portion defined by an adjacent pair of proximal and distal peak portions and a sidewall segment connecting the peak portions. The sidewall segment and membrane electrode assembly at least partially define a flow channel. The sidewall segment includes a shoulder portion defining a step spaced away from the peak portions.

Electromagnetic manufacturing method and forming device of mesoscale plate are provided. The manufacturing method includes: oppositely and parallelly disposing a first workpiece to be formed on top of a mold, side-press restraining two ends of the first workpiece, and disposing a deceleration block on two sides of the mold; controlling the first workpiece to tend toward the mold and to be deformed under the drive of uniform electromagnetic force; and colliding a middle area of the first workpiece firstly with the mold under the drive of uniform electromagnetic force, and driving the speed of the middle area of the first workpiece to decelerate to zero. When an area close to the two ends collides with the deceleration block and until the speed of all areas of first workpiece decelerates to zero, forming is completed. Shaping is tending further toward the mold through electromagnetic force until completely fitted to the mold.

A plurality of channel elements provided in a bipolar plate have different widths depending on positions, so that the velocity of flow of the fluid increases from an inlet toward an outlet of the bipolar plate and water generated when the fluid is condensed on the downstream side of the bipolar plate can be discharged more smoothly. In addition, a plurality of channel elements have different contact angles depending on positions of the plurality of channel elements so that the contact angle increases toward the outlet side of the bipolar plate. Thus, the reaction gas can be more concentrated on the surface of a gas diffusion layer. Even if the concentration of the reaction gas is reduced at the outlet side of the bipolar plate, the diffusion of the reaction gas is well performed, so that performance reduction can be prevented.

A bipolar plate of an electrochemical cell, including a first conductive sheet and a second conductive sheet, wherein at least one first distribution channel of a first conductive sheet and one second distribution channel of a second conductive sheet each include at least one portion, referred to as a superposed portion, where they are superposed onto one another and make mutual contact via their respective back walls, and at least one portion, referred to as a reinforcement portion, where they make contact, via their respective back walls, with a dividing rib of the opposite conductive sheet.

The invention pertains to a bipolar plate in which each of the distribution channels is located facing a dividing rib of the opposite conductive sheet; and in which said distribution channels include portions of various depths that are arranged so as to form a longitudinal alternation between: an enhanced distribution zone, in which: the distribution channels have a combined cross section of a high distribution value, and the cooling channels have a combined cross section of a low cooling value; and an enhanced cooling zone, in which: the distribution channels have a combined cross section of a value that is lower than the high distribution value, and the cooling channels have a combined cross section of a value that is higher than the low cooling value.

The invention pertains to a bipolar plate in which each of the distribution channels is located facing a dividing rib of the opposite conductive sheet; and in which said distribution channels include portions of various depths that are arranged so as to form a longitudinal alternation between: an enhanced distribution zone, in which: the distribution channels have a combined cross section of a high distribution value, and the cooling channels have a combined cross section of a low cooling value; and an enhanced cooling zone, in which: the distribution channels have a combined cross section of a value that is lower than the high distribution value, and the cooling channels have a combined cross section of a value that is higher than the low cooling value.

In a fuel cell separator comprising gas flow channels composed of a plurality of concavoconvex parts in the center region and flat parts on the periphery of the gas flow channels, the fuel cell separator provided with the first bent parts that bend approximately vertically to the same direction respectively at both edge parts at least in one direction among on flat parts in both directions of gas flow channels, and the second bent parts between gas flow channel-side flat parts and edge-side flat parts on the flat parts in the inward from the first bent parts on both sides with a smoothly curved cross-sectional shape of the gas flow channel-side bent ends of the second bent parts, and the production method thereof.

A separator for a fuel cell includes a thin metal plate, protrusions that are formed on the metal plate to be close to each other, and gas passages formed by the protrusions. Each gas passage has a first opening corresponding to an inlet and a second opening corresponding to an outlet. The gas passages include a first gas passage, which has a relatively low pressure loss of gas flow, and a second gas passage, which has a relatively high pressure loss of gas flow. The area of the first opening of the first gas passage is set to be smaller than the area of the first opening of the second gas passage.

A separator for a fuel cell includes a thin metal plate, protrusions that are formed on the metal plate to be close to each other, and gas passages formed by the protrusions. Each gas passage has a first opening corresponding to an inlet and a second opening corresponding to an outlet. The gas passages include a first gas passage, which has a relatively low pressure loss of gas flow, and a second gas passage, which has a relatively high pressure loss of gas flow. The area of the first opening of the first gas passage is set to be smaller than the area of the first opening of the second gas passage.

An undulating structure for use in a fuel cell includes a plurality of peaks and valleys. A method of making a structure for use in a fuel cell includes providing a mesh or screen sheet having one or more edges, forming the mesh or screen sheet into an undulating structure and treating one or more of the edges. A flow field for a fuel cell, comprising at least one metal mesh or screen, wherein the at least one metal mesh or screen includes a plurality of peaks and valleys. A fuel cell, comprising a first corrugated mesh or screen positioned within an anode of the fuel cell, a second corrugated mesh or screen positioned within a cathode of the fuel cell, and a membrane positioned between the first corrugated mesh or screen and the second corrugated mesh or screen.