A separator for a fuel cell includes protrusions and gas passage portions. The protrusions each include a contact surface configured to contact a power generation portion. The gas passage portions are each arranged between two adjacent ones of the protrusions. An upstream side and a downstream side are defined with reference to a direction in which reactant gas flows through the gas passage portions. The protrusions each include a downstream end. The contact surfaces of the protrusions each include a first groove extending along an extending direction of the protrusions. The downstream end of each of the protrusions includes a separation surface. The separation surface is continuous with the contact surface on the downstream side and separated from the power generation portion. The separation surface includes a second groove that is continuous with the first groove.

A separator for a fuel cell includes a contact surface configured to contact a power generating unit of the fuel cell. Groove passages are arranged side by side in the contact surface. Reactant gas flows through the groove passages. At least one of the groove passages includes a wavy section that extends in a wavy shape in planar directions of the contact surface. An upstream portion and a downstream portion in a flow direction of the reactant gas in each groove passage are defined as an upstream portion and a downstream portion, respectively. A wavelength of the wavy section is smaller in the downstream portion than in the upstream portion.

A separator for a fuel cell includes a contact surface configured to contact a power generating unit of the fuel cell. Groove passages are arranged side by side in the contact surface. Reactant gas flows through the groove passages. At least one of the groove passages includes a wavy section that extends in a wavy shape in planar directions of the contact surface. An upstream portion and a downstream portion in a flow direction of the reactant gas in each groove passage are defined as an upstream portion and a downstream portion, respectively. A wavelength of the wavy section is smaller in the downstream portion than in the upstream portion.

A fuel cell bipolar flow field plate and a fuel cell stack are provided. The fuel cell bipolar flow field plate includes a first gas channel and a second gas channel. Each of the gas channels has several sub-channels, each of the sub-channels has bending parts, and adjacent sub-channels have opposite flow directions. The sub-channels of the two gas channels form a four-leaf clover type pattern in a reaction area of the fuel cell bipolar flow field plate. A bending angle of each of the bending parts in the four-leaf clover type pattern is within 90 degrees.

A fuel cell bipolar flow field plate and a fuel cell stack are provided. The fuel cell bipolar flow field plate includes a first gas channel and a second gas channel. Each of the gas channels has several sub-channels, each of the sub-channels has bending parts, and adjacent sub-channels have opposite flow directions. The sub-channels of the two gas channels form a four-leaf clover type pattern in a reaction area of the fuel cell bipolar flow field plate. A bending angle of each of the bending parts in the four-leaf clover type pattern is within 90 degrees.

Disclosed is a separator for a fuel cell. The separator includes a separator main body formed in a plate shape such that a first surface thereof forms a reaction surface and a second surface thereof forms a cooling surface, each of which has a reaction area at a center portion thereof and formed with multiple manifold areas through which multiple manifolds to which a reaction gas or a coolant is respectively introduced or discharged pass to opposite sides of the reaction area, and in which a pair of diffusion areas that diffuse the reaction gas or the coolant are formed between the reaction area and the pair of manifold areas, and includes multiple flow path guide gaskets formed on the pair of diffusion areas and configured such that multiple diffusion flow paths dispersed to the reaction area from at least a pair of the manifolds respectively formed on the pair of manifold areas are formed.

A fuel cell that includes one or more fuel cell bipolar plates having a bipolar plate body with an inlet region, an outlet region, a reaction region arranged between and fluidically connected to the inlet region and the outlet region, and one or more microchannel fluid flow networks extending from the inlet region to the outlet region. The microchannel fluid flow networks include a plurality of primary flow microchannels having one or more secondary flow microchannels branching therefrom to facilitate reaction uniformity and fluid flow resistance through the fuel cell.

A fuel cell that includes one or more fuel cell bipolar plates having a bipolar plate body with an inlet region, an outlet region, a reaction region arranged between and fluidically connected to the inlet region and the outlet region, and one or more microchannel fluid flow networks extending from the inlet region to the outlet region. The microchannel fluid flow networks include a plurality of primary flow microchannels having one or more secondary flow microchannels branching therefrom to facilitate reaction uniformity and fluid flow resistance through the fuel cell.

A bipolar plate for a proton exchange membrane fuel cell includes a laminate of carbon fiber reinforced plastic (CFRP) with a first outer ply. The CFRP includes a resin and carbon fibers. The first outer ply is arranged at a first lateral surface of the laminate, wherein the laminate includes a first plurality of carbon nanotubes (CNTs). The first outer ply includes a first groove, wherein the first groove is configured to define a first gas diffusion channel. At least some of the first plurality of CNTs extend through the first outer ply in a direction transversely to the first lateral surface of the laminate.

A bipolar plate for a proton exchange membrane fuel cell includes a laminate of carbon fiber reinforced plastic (CFRP) with a first outer ply. The CFRP includes a resin and carbon fibers. The first outer ply is arranged at a first lateral surface of the laminate, wherein the laminate includes a first plurality of carbon nanotubes (CNTs). The first outer ply includes a first groove, wherein the first groove is configured to define a first gas diffusion channel. At least some of the first plurality of CNTs extend through the first outer ply in a direction transversely to the first lateral surface of the laminate.