ASSESSMENT OF FUEL CELL'S CONTACT PRESSURE DISTRIBUTION BY MEANS OF DISTRIBUTED FILM SENSORS AND DIGITAL IMAGE CORRELATION TECHNIQUES

The achievement of proper electrochemical performance in proton exchange membrane fuel cells depends on a number of factors, among which the difficulty in obtaining a uniform pressure distribution over the whole fuel cell active area. For a given stacking design, contact pressure levels are usually controlled by selecting an appropriate external clamping pressure on the endplates. Hence, the actual out-of-plane deformation of the endplates is believed to play a critical role. The goal of this study is to investigate this aspect by using an optical full-field measurement technique based on stereoscopic digital images correlation. The preliminary results reported in this paper, obtained by testing a PEMFC with 13 mm thick Cu endplates, shows that the endplates bend noticeably under loading, leading to an uneven distribution of the out-of-plane deformation field.