Experimental Study And Physical Parameters Characterization Of Ion-exchange Membrane

Based on the background of"two carbon",fuel cells have ushered in a period of rapid development,and ion exchange membranes are the essential components of Proton exchange membrane（PEM）fuel cells and Anion exchange membrane（AEM）fuel cells.At present,the ion exchange membranes used by domestic fuel cell automotive companies mainly rely on foreign brands,and their internal physical parameters are not disclosed to the public,which makes it more difficult to develop domestic fuel cell products.In particular,the simulation work lacks empirical formulas for conductivity,hydration,and other relevant physical parameters,which makes it difficult to obtain the relevant characteristic parameters accurately and thus affects the accuracy of simulation results.Therefore,there is an urgent need to carry out research on the characterization methods of physical properties parameters of ion exchange membranes.In this paper,we have built a water diffusion coefficient characterization platform for Alkymer,Orion,Pention and Gore membranes,which can obtain a complete set of empirical equations for the variation of relevant physical parameters with temperature and humidity by measuring the transmembrane transport water flux and combining with the existing characterization methods for hydration and conductivity,thus making up for the difficulties in the simulation work in the context of the rapid update and iteration of membrane materials.In the context of the rapid iteration of membrane materials,the inadequacy of characterization methods and empirical formulas has laid a certain foundation for the localization and development of ion exchange membranes.The main research of this paper includes:（1）We have characterized the physical parameters such as hydration,conductivity,and water diffusion coefficient of Alkymer,Orion,and Pention anion exchange membranes,and designed and built the water diffusion coefficient test platform independently to complete the characterization of each physical parameter of the membranes.（2）Two membranes,Alkymer and Orion,were prepared and assembled into a single cell for variable sensitivity testing.The effects of different temperature,humidity and cathode stoichiometry ratios on the performance of AEMFC were tested,and suggestions for performance optimization were given.（3）The Gore membrane was characterized for relevant physical parameters such as hydration,conductivity,and water diffusion coefficient,and empirical equations were fitted.And based on the Gore film,the MEA was prepared,and the PEMFC polarization curve as well as the EIS test were performed to achieve the ultimate current density above 2.2 A·cm^-2.（4）Combined with the Gore empirical formula obtained from the characterization of this paper,the one-dimensional model was improved,and then the polarization curves and EIS curves obtained from the single-cell experiments of this paper were simulated to accurately calibrate the polarization curves and ohmic losses.