Patent ID: 7972748

Claim:
A fuel cell comprising: a membrane electrode assembly (MEA); a source of fresh operating substances; a bipolar plate having: an anode-side gas distributor structure for distributing anode reactants, a cathode-side gas distributor structure for distributing cathode reactants, a guide passage structure for distributing a cooling medium, wherein at least one of the anode-side gas distributor structure and the cathode-side gas distributor structure is divided into at least a first field and a second field, each of the first and second field having an entry port and an exit port for the reactants, the reactants being depleted in the first field between the entry port and the exit port, and an inlet port coupled to the source of fresh operating substances and at least one of the exit port of the first field and the entry port of the second field for introducing fresh operating substances into the at least one of the anode-side gas distributor structure and the cathode-side gas distributor structure so that the fresh operating substances mix with the reactants that are depleted in the first field and form a mixture that passes into the second field.