Design and performance study of a kilowatt-class PEMFC stack with metal fiber felts as flow fields

Abstract

The study presents a comprehensive design and evaluation of a kilowatt-class proton exchange membrane fuel cell (PEMFC) stack, wherein stainless steel fiber felts are innovatively utilized as flow fields. The impacts of critical operating parameters, namely operating temperature, pressure, and reactant gas relative humidity, on the performance of the 22-cell stack with an active area of 83 cm2 were thoroughly investigated. An analysis of the voltage consistency among individual cells was conducted across varying operating conditions and output currents. The total power output of the PEMFC stack reaches 1183 W under the fundamental operating conditions, where each cell achieves an average voltage of 0.6 V. As the operating temperature and pressure are incremented, the stack’s output power exhibits a noticeable increase. The optimal range for the reactant gas relative humidity is found to be 60–80 %. As the output current increases, the voltages of individual cells gradually decrease and the voltage consistencies tend to deteriorate. The optimal operating conditions for achieving the best voltage consistency vary with current density.