Influence of cathode stoichiometry on operation of PEM fuel cells' stack supplied with pure oxygen

摘要

As a part of ongoing research into the use of fuel cells to power underwater platforms, studies have been conducted to investigate the effect of change in oxygen flow through the proton exchange membrane fuel cell (PEM-FC) cathode channel, to develop a method for controlling this flow. Due to the lack of specific information or studies on the effect of pure oxygen flow through the PEM-FCs cathode channel on the correctness of its work, a series of experiments have been carried out within the framework of in-house research to determine this dependence. The experiment was conducted in series, during which the only change in the operating parameter of the PEM-FC stack was the stoichiometric flow rate of oxygen supplied to the cathode channel of the fuel cells' stack. The research shows that for the PEM-FCs stack fed with pure oxygen, the cathode stoichiometry can be kept at a much lower level comparing to the systems supplied with air. It has been found that the fuel cells' stack fed with pure oxygen will perform well in steady state while reducing the cathode stoichiometry by as much as 40% compared to systems utilising oxidant from atmospheric air.