Bipolar plate for fuel cells, and production method

A bipolar plate for proton-exchange membrane PEM fuel cells, which are made with a metallic substrate and on their surface with an electrical contact resistance-reducing carbon-based layer, a layer system or a boundary layer which is made of a near-surface sp2-bonded, carbon-based layer which has a carbon fraction ranging from 50% to 100% and which is applied on a metallic substrate surface modified relative to the starting material, and

• a surface region of the metallic substrate is present as edge layer, which is made with nitride or carbon by nitriding or carburizing,
• the metallic substrate has a surface which is in contact with a gas-permeable element within the PEM cells and the surface has elevations or depressions, wherein
• the elevations or depressions on the metallic substrate surface have dimensions and geometrical design such that fibers, with which the gas-permeable element is made as a textile structure, which are
• in touching contact over their periphery with at least 10% of their outer lateral surface, on the metallic substrate surface region in which the depression is present and in which the fibers and the substrate surface touch one another.