Investigation, modeling, and optimization of parameters affecting sulfonated polyether ether ketone membrane-electrode assembly Aida Karimi a , Milad Shakouri Kalfati a , Soosan Rowshanzamir a,b,* a School of Chemical Engineering, Iran University of Science and Technology, Narmak, Tehran 16846-13114, Iran b Fuel Cell Laboratory, Green Research Centre, Iran University of Science and Technology, Tehran, Iran article info Article history: Received 16 August 2018 Received in revised form 10 October 2018 Accepted 30 October 2018 Available online 29 November 2018 Keywords: Fuel cells Membrane Modeling Optimization Proton exchange membrane fuel cell Sulfonated poly ether-ether ketone abstract A model of a membrane-electrode assembly (MEA) with a Sulfonated Poly Ether-Ether Ketone (SPEEK) membrane is presented and compared with Nafion membrane MEA. The model used the specific hydration and proton conductivity curves developed for SPEEK membrane and accounted for feed-gas momentum and mass transfer, electro-potential in both the electrode and electrolyte fields. The model is first used to obtain and compare the polarization curve of the cell in different water activity of the feed gases for both SPEEK and Nafion. Then, Operating parameters like temperature, pressure, and water mass fraction in feed gases were optimized for maximum power density production of SPEEK membrane using response surface method (RSM). The results indicated that the SPEEK MEA could compete with Nafion in the presence of liquid water at a normal operational temperature (80  C) and surpass it at a higher temperature. Optimization results contribute to guidelines for the practical use of the SPEEK membrane in PEMFCs. Outcomes signified that operating at high temperature is only favorable in high pressure and water content of the anode feed gas, due to the high sensitivity of proton conductivity of SPEEK membrane to the water activity. © 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. Introduction Proton exchange membrane Fuel cells (PEMFCs) have received extensive attention recently as a promising sustainable energy-delivery device [1]. Perfluoro sulfonic acid (PFSA) membranes such as Nafion are the most commonly used membrane as a proton exchange membrane (PEM) since this type of membranes offers excellent chemical and mechanical stability and excellent proton conduction. However, this kind of membrane is costly and have a high amount of feed-gas crossover, hence, finding a low-cost substitute for them has been one of the primary goals of recent studies in this field. Sulfonated Aromatic Polymers (SAP) are attractive among the other alternatives due to their reasonable price, ability to work at higher temperatures and their less feed-gas crossover. Extensive efforts have been made to investigate the manufacturing of a PEM using SAPs. Sulfonated polyether ether ketone which is one of the most distinguished SAPs, having good mechanical and thermal stability and proton conductivity. Numerous studies conducted to investigate synthesis, properties of this membrane as a PEM. * Corresponding author.School of Chemical Engineering, Iran University of Science and Technology, Narmak, Tehran 16846-13114, Iran. E-mail address: rowshanzamir@iust.ac.ir (S. Rowshanzamir). Available online at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/he international journal of hydrogen energy 44 (2019) 1096 e1109 https://doi.org/10.1016/j.ijhydene.2018.10.225 0360-3199/© 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.