Fluorinated Poly(aryl piperidinium) Membranes for Anion Exchange Membrane Fuel Cells

Abstract

Anion-exchange-membrane fuel cells (AEMFCs) are a cost-effective alternative to proton-exchange-membrane fuel cells (PEMFCs). The development of high-performance and durable AEMFCs requires highly conductive and robust anion-exchange membranes (AEMs). However, AEMs generally exhibit a trade-off between conductivity and dimensional stability. Here, a fluorination strategy to create a phase-separated morphological structure in poly(aryl piperidinium) AEMs is reported. The highly hydrophobic perfluoroalkyl side chains augment phase separation to construct interconnected hydrophilic channels for anion transport. As a result, these fluorinated PAP (FPAP) AEMs simultaneously possess high conductivity (>150 mS cm −1 at 80 °C) and high dimensional stability (swelling ratio <20% at 80 °C), excellent mechanical properties (tensile strength >80 MPa and elongation at break >40%) and chemical stability (>2000 h in 3 m KOH at 80 °C). AEMFCs with a non-precious Co-Mn spinel cathode using the present FPAP AEMs achieve an outstanding peak power density of 1.31 W cm −2 . The AEMs remain stable over 500 h of fuel cell operation at a constant current density of 0.2 A cm −2 .

N‐Methylquinuclidinium‐Based Anion Exchange Membrane with Ultrahigh Alkaline Stability

“…It should be noted that it has a low SR between 20 and 80 °C, which is lower than most of the state‐of‐art AEMs (Figure 3d, Figure S7, Supporting Information). [ 8,13,14,20–26 ]…”

Oxidative instability of ionomers in hydroxide-exchange-membrane electrolyzers

“…The aromatic regions of HEM backbones are likely weak sites for oxidation, 40,41,44 therefore a fully sp 3 -hybridized backbone should be more resistant to oxidative damage. These and related polymers have shown promising performance and durability in HEM fuel cells 50,51 and electrolyzers. [52][53][54] Anode PTEs were prepared using Co3O4 catalyst and the PNB ionomer on a woven stainlesssteel substrate.…”

Alkaline Membranes toward Electrochemical Energy Devices: Recent Development and Future Perspectives

“…Hence, the oxidation degradation is an emerging concern. At present, Fenton’s reagent is a widely adopted tool for oxidation stability evaluation. , But it should be pointed out that this tool is not very suitable for assessing the oxidation stability of alkaline membranes used in an alkaline environment. Because it only supports hydroxyl and hydroperoxyl radicals under acidic conditions, while in alkaline environment, more hydroxyl and superoxide radicals are generated.…”