![]() At a temperature of 80 ☌ and maximum hydration, it has been reported to achieve an OH − anion conductivity of 148 mS cm −1. This self-supporting membrane is manufactured from functionalised poly (aryl piperidinium) resin material without mechanical reinforcement. 11–13 Ether-free polybenzimidazoles (PBIs) containing alicyclic and aliphatic segments have been reported to achieve OH − anion conductivity of 108.8 mS cm −1 at 80 ☌ and a peak power density of 785 mW cm −2 at a current density of 1802.9 mA cm −2. Their membrane structure contains no ether group for better hydrolysis stability, better performance at elevated temperatures, and enhanced durability in fuel cells and electrolysers. These AEMs are prepared by superacid catalysis. At a temperature of 80 ☌ and 95% relative humidity (RH), it has been reported to achieve an OH − anion conductivity of 145 mS cm −1. This low-density polyethylene contains covalently bonded benzyl trimethyl-ammonium and cationic head groups. 5,8,9 Attempts to balance the mentioned factors have resulted in the development of several promising AEMs. 3 However, the biggest challenge for the practical application of AEMFCs is concurrently achieving a high power performance and cell durability. This results in lower ionic conductivities than those of commercial PEMs. 3 Unlike –SO 3H groups in proton exchange membranes (PEMs), such as Nafion®, anion-exchange groups do not strongly dissociate, and the electrochemical mobility of OH − in water is lower than that of H +. It is challenging to fabricate AEMs with high OH − ion conductivity and good mechanical properties 3 increasing the ion exchange capacity (IEC) of the membrane improves the ion conductivity but is often accompanied by a drop in the mechanical properties, such as increased swelling and brittleness. 3 A viable fuel cell membrane must display high ion conductivity (≥100 × 10 −3 S cm −1 7), high durability, mechanical/thermal/chemical stability, a robust synthetic route, and cost-effectiveness. One of the biggest challenges in commercialising AEMFCs has always been the anion exchange membrane (AEM). Combining the cheaper catalysts, cheaper cell building materials and reported excellent high-temperature performance can dramatically lower overall fuel cell cost per kilowatt and enable widespread technology commercialisation. 6 demonstrated that, at high temperatures (110 ☌), an AEMFC yielded better performance values than those reported for PEMFCs at the same temperature. AEMs are also alkaline by definition, allowing for cheaper cell components because of the reduced corrosiveness. AEMFCs operate in the same temperature range but can potentially be independent of Pt-group metal-based catalysts. However, their dependency on Pt has necessitated intensified research on anion exchange membrane fuel cells (AEMFCs). 1–4 In the case of portable applications such as in the automotive industry, proton exchange membrane fuel cells (PEMFCs) offer the highest power density, efficiency, and durability. Silence and quick refuelling are especially attractive for automobile use. Not only is the system energy efficient, with no production of CO 2, but the technology also has the added benefits of quietness and rapid refuelling. Fuel cell technology is considered an integral part of an overall effective solution to this problem. Introduction With the growing urgency to address global warming, curbing emissions from human activity is becoming increasingly necessary. The availability of this technique is an essential prerequisite in improving the ionic conductivity and effectively solving the persisting durability challenge facing AEMFCs, thus hastening the possibility of mass commercialisation of fuel cells. These results confirm the viability of micro-Raman spectroscopy in studying the various water-related species in AEMs. All the hydrogen-bonded OH species increased steadily with increasing humidity, while the CH and non-H-bonded OH remained relatively constant. The OH stretching band was deconvoluted into nine unique Gaussian bands. Spectra of pure water, alkaline solutions, and calculations based on density functional theory were used to identify the water species in the AEM. In this paper, different water species inside an anion exchange membrane (AEM), QPAF-4, developed at the University of Yamanashi, were studied for the first time using micro-Raman spectroscopy. Water characterization inside the membrane is one factor that significantly influences the performance of AEMFCs. Unlike PEMFCs, AEMFCs have demonstrated the capability to operate independently of Pt group metal-based catalysts. Anion exchange membrane fuel cells (AEMFCs) hold the key to future mass commercialisation of fuel cell technology, even though currently, AEMFCs perform less optimally than proton exchange membrane fuel cells (PEMFCs).
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