The degradation of anion exchange membranes (AEMs) hindered the practical applications of alkaline membrane fuel cells. This issue has inspired a large number of both experimental and theoretical studies. However,...

The chemical stability of anion exchange membranes (AEMs) greatly affects their practical applications in alkaline membrane fuel cells. Here, highly conductive and dimensionally stable AEMs based on a copolymer with a triphenylmethane backbone (without aryl ether linkages) were prepared via Friedel−Crafts polycondensation. The as-prepared AEMs showed a high hydroxide conductivity (124.2 mS cm −1 at 80 °C) and good alkaline stability in 2 M KOH solution at 60 °C. Furthermore, the AEMs with high ion exchange capacity (IEC: 2.17 mmol g −1 ) displayed high mechanical properties and good dimensional stability. The single H 2 /O 2 fuel cell utilizing the PDMB-Pi-0.7 membrane showed a maximum power density of 212.8 mW cm −2 at a current density of 425.5 mA cm −2 at 60 °C. This study provides a general synthesis strategy for the preparation of stable AEMs with high hydroxide ion conductivity and good dimensional stability for alkaline membrane fuel cells.

The performance of alkaline fuel cells is severely limited by substandard anion exchange membranes (AEMs) due to the lower ionic conductivity compared to the proton exchange membranes. The ionic conductivity of AEMs can be effectively improved by regulating the microphase structure, but it still cannot meet the practical use requirements. Here, enhanced microphase‐separated structures are constructed by the cooperativity of highly hydrophilic dual cations and highly hydrophobic fluorinated side chains. Meanwhile, the introduction of O enhances the flexibility of side chains and facilitates the formation of ion transport channels. The dual piperidinium cation functionalized membrane (PB2Pip‐5C8F) which is grafted with the ultra‐hydrophobic fluorocarbon chain exhibits a high conductivity of 74.4 mS cm−1 at 30 °C and 168.46 mS cm−1 at 80 °C. Furthermore, the PB2Pip‐5C8F membrane achieves the highest peak power density of 718 mW cm−2 at 80 °C under a current density of 1197 mA cm−2 without back pressure. A long‐term life cell test of this AEM shows a low voltage decay rate of 1.68 mV h−1 over 70 h of operation at 80 °C.

C60‐cored star polyfluorenes were synthesized and fully characterized. A high yield (81%) hexakisaddition of C60 was developed by using Prato reaction and bulky fluorene addends. Suzuki polycondensation of the hexakisadducts of C60 carrying six 2‐bromofluorene addends and AB‐type monomer (2‐bromo‐9,9‐dioctylfluorenyl‐4,4,5,5‐tetramethyl‐ [1,3,2]‐dioxaborane) with Pd(PPh3)4 as the catalyst precursor afforded the desired C60‐cored star polyfluorenes. Their three‐dimensional structure can effectively reduce the aggregation of the polyfluorene chains. Annealing studies indicated that the C60‐cored star polyfluorenes are of good color stability. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4696–4706, 2007

The gas permeability of the catalyst layer was increased by 130% after crosslinking due to the high free volume.