Effect of humidification and cell heating on the operational stability of polymer electrolyte membrane fuel cell

Abstract

Because of its clean or zero-emission nature, the PEM fuel cell is considered a potential energy conversion device for power production. The performance of the PEM fuel cell is known to be influenced by many parameters, such as operating temperature, pressure, and humidification of the reactants. In addition, the operational stability of the PEM fuel cell under these conditions with the purging of water during its operation should also be studied to understand the performance of the PEM fuel cell. Therefore, this paper brings out the effects of cell humidification and cell heating on the performance, especially the operational stability concerning the liquid water removal of the PEM fuel cell. The experiments are conducted on a single PEM fuel cell with mixed flow distributors operating on different cell temperatures and humidification conditions. At dry feed operation of the PEM fuel cell at ambient condition, the cell utilizes around 80.3% of water generated for its membrane hydration, i.e., self-humidification. When the PEM fuel cell is operated at full humidification (100% RH) on both sides, the membrane is well hydrated, and the cell attains the maximum power density of 0.25 W/cm2, which is 56% more than dry feed operation. The results of the experiments at static current density demonstrate membrane hydration is the significant factor for both stable operation and efficient power output. External purging must periodically be carried out to stabilize the cell due to voltage fluctuations. The major outcome of the current study is to establish the connection between hydration and the stability of the PEM fuel cell.