1,2-Dimethylimidazolium-functionalized cross-linked alkaline anion exchange membranes for alkaline direct methanol fuel cells

摘要

The cross-linked and alkali stable alkaline anion exchange membranes (AAEMs) based on 1,2-dimethylimidazolium (proved to be much more stable than C2-unsubstituted imida-zolium cation) were prepared by a hot-pressing method. The properties of these membranes, e.g., water uptake, swelling degree, ion-exchange capacity, conductivity and thermal and chemical stability, were characterized systematically. The swelling degree of the membranes decreases with the decrease of the amount of 1,2-dimethylimidazolium salt, up to 5.8%. The membranes are thermally stable below 200 ℃. Alkaline direct methanol fuel cell (ADMFC) fabricated by using CoO_x/C as the cathode catalyst and PtRu/C as the anode catalyst presents a promising performance with the peak power density of 12.7 mW cm~(-2) at a current density of 45 mA cm~(-2), indicating that the 1,2-dimethylimidazolium-functionalized AAEMs are promising for the application in ADMFCs.