Ex situ aging effect on sulfonated poly(ether ether ketone) membrane:Hydration-dehydration cycling and hydrothermal treatment

作     者：Seung-Young Choi Kyeong Sik Jin Seung-Young Choi;Kyeong Sik Jin

作者机构：Polymer&Materials ChemistryDepartment of ChemistryLund UniversitySE-22100Sweden Center for Hydrogen·Fuel Cell ResearchKorea Institute of Science and Technology(KIST)Seoul 02792Republic of Korea Pohang Accelerator LaboratoryPohang University of Science and Technology(POSTECH)PohangKyungbuk 37673Republic of Korea 

出 版 物：《Journal of Energy Chemistry》 (能源化学（英文版）)

年 卷 期：2022年第31卷第7期

页      面：583-592,I0014页

核心收录：

学科分类：0808[工学-电气工程] 07[理学] 070205[理学-凝聚态物理] 08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：Byoungseok Min of Pohang Accelerator Laboratory for SAXS technical support at 4C beamline.All authors have read the manuscript and agreed to its contents 

主　　题：Sulfonated poly(ether ether ketone) Humidity cycle test Ex situ aging Proton exchange membrane Fuel cell 

摘      要：Prolonged hydrothermal treatment for sulfonated poly(ether ether ketone) membranes induces mechanical degradation and developing hydrophilic-hydrophobic phase separation, simultaneously. The enhanced phase separation provides incremental proton conductivity to the membranes, whereas mechanical degradation drastically reduces device stability. On this basis, we describe here the effects of two different ex situ aging processes on sulfonated poly(ether ether ketone) membranes: hydrationdehydration cycling and prolonged hydrothermal treatment. Both aged membranes exhibited enhanced phase separation under the hydrated conditions, as characterized by small angle X-ray ***, when the aged membranes were dried again, the nanostructure of the membranes aged via the hydration-dehydration cycling was recoverable, whereas that of the membranes aged via prolonged hydrothermal treatment was irreversible. Furthermore, the two differently aged membranes showed clear differences in thermal, mechanical, and electrochemical properties. Finally, we implemented both aged membranes in fuel cell application. The sample aged via hydration-dehydration cycling maintained its improved cell performance, whereas the sample aged via hydrothermal treatment showed drastically reduced cell performance after durability test for 50 h.