应用于阴离子交换膜燃料电池的阴离子导电聚合物:通过增强微相分离结构实现互联离子传输通道OA

The performance of anion exchange membrane fuel cells(AEMFCs)is severely constrained by the low OH-conductivity of anion-conductive polymers.Although increasing the ion exchange capacity of these polymers through microstructural design effectively improves the OH-conductivity,it often compromises the mechanical strength.To address this issue,we report enhanced microphase-separated structures in poly(styrene-b-(ethylene-co-butylene)-b-styrene)(SEBS)-based anion-conductive polymers,achieved through the synergy of hydrophilic quaternary ammonium(QA)groups and hydrophobic fluorinated side chains.Specifically,by precisely tuning the fluorine grafting degree of the polymer side chains,highly interconnected nanoscale ion-conducting domains are created,forming a three-dimensional(3D)pathway for efficient ion transport in anion exchange membranes(AEMs).Additionally,the mechanical stability of AEMs is strengthened by minimizing swelling.As a result,the QA-and fluorine-grafted AEM with a molar proportion of 4-fluorophenethylamine-modified blocks to styrene blocks of 30%(denoted as QSEBS-FPh30)achieves a high OH-conductivity of 100.86 mS/cm at 80℃and a moderate tensile strength of 19.89 MPa in a fully hydrated state.The AEMFC utilizing QSEBS-FPh30 exhibits a peak power density of 204.31 mW/cm2 at a current density of 737.29 mA/cm2 and 80℃,which is 1.4 times that of QA-grafted SEBS(QSEBS).These findings underscore the significant role of microphase separation coupled with maximized ionic domain connectivity in enhancing the OH-conductivity of anion-conductive polymers,offering valuable insights for the rational design of high-performance AEMs.