The effects of compression and gas diffusion layers on the performance of a PEM fuel cell

Changes in the performance of a PEM fuel cell are presented as a function o f the compression pressure resulting from torque on the bolts that clamp th e fuel cell. Three types of gas diffusion layers were studied at 202 kPa an d 353 degrees K. An optimum bolt torque was observed when ELAT(R) or a comb ination of CARBEL(R) and TORAY(TM) gas diffusion media were used as diffusi on layers. The optimum is related to the gasket thickness and the measured compression pressure on the diffusion layer. The performance changes may al so be related to changes in the porosity, the electrical contact resistance , and the excluded water at the membrane. (C) 1999 Elsevier Science S.A. Al l rights reserved.