PROCESS FOR OPERATING A FUEL CELL STACK

摘要

A process is disclosed for operating a fuel cell stack having at least one individual cell, in particular a PEM fuel cell, as well as the use of a structure which is known per se for carrying out a preferred embodiment of this process. In this process, hydrogen or a hydrogen-containing gas is supplied as fuel to an anode chamber of the fuel cell stack, and oxygen or air is supplied as oxidising agent to a cathode chamber of the fuel cell stack. According to the invention, the oxidising agent is at least partially diluted. This makes it possible to adjust such a partial oxygen pressure in the oxidising agent that the voltage supplied by each of the individual cells remains under a critical voltage value. The oxidising agent is preferably diluted with recycled waste cathode gas.