Abstract
An important problem for medium temperature polymer electrolyte fuel cells (MT PEMFCs) operating in the temperature range 90–140 °C is the short time‐life of proton conducting membranes. Kinetic experiments showed that, for each couple of T–RH values, the water taken up from the membrane reaches a constant value only after long times of equilibration (≥200 h). Taking into account that the enlargements provoked by the water‐uptake remain as permanent deformations when the samples are cooled, it was found that the evolution of the deformations provoked by changes in temperature and RH can be conveniently estimated at 20 °C by determining the water taken up after equilibration in liquid water. By relating the counter‐elastic index of the matrix (nc(m)) to the extent of these deformations, a set of equations were obtained which allowed us to predict their evolution with changes of temperature and relative humidity. A good agreement with experimental values was found. The importance of this discovery for the development of MT PEMFCs is discussed.
Details
Published on: Fuel Cells 2009, 9, 410-420
Authors: G. Alberti, R. Narducci