Experimental Study on the Performance Enhancement of an Air-Cooled Open Cathode Proton Exchange Membrane Fuel Cell With Metallic Bipolar Plate

Abstract

The air-cooled fuel cells are widely used in the portable power supply systems owing to their simple structure, small volume, light weight, and high power density. In this paper, a compact 3 kW air-cooled fuel cell stack consists of 95 single cells with high weight power density is designed, the transient behaviors of the voltage and temperature of each cell are analyzed. The results show that the heat distribution of the air-cooled fuel cell is very uniform, and the temperature difference between the inlet and outlet of cathode air of the fuel cell is lower than 15 °C. The individual cell voltage uniformity percentage variation value Cv reaches 7% when the drop in the loading current is over 25 A. Moreover, the Cv value is greater than 4% when the loading current output exceeds 35A. Thus, a large drop in loading and a high loading current easily increase the Cv value. Long-term continuous operation has a negative influence on the performance of the stack, especially the last fuel cell near the anode outlet. Anode purging can effectively alleviate the uniformity percentage variation in the voltages. The designed air-cooled fuel cell exhibits good performance and strong environmental adaptability.

Keywords: proton exchange membrane fuel cell, air-cooled, Metallic bipolar plate, Dynamic response, Voltage uniformity