The substantial advancements and availability of new cost-effective materials have drawn significant attention to the anion-exchange membrane fuel cell (AEMFC) technology. The anion exchange membrane (AEM) is a core component in AEMFCs, essential for conducting hydroxide ions and controlling water transport between the fuel cell electrodes. In this study, we apply a numerical model to investigate the relationship and sensitivity of AEMFC performance and its stability to key AEM properties. Our findings show that membrane maximum hydration level (λmax) has the most significant impact on AEMFC lifetime, followed by membrane ion-exchange capacity, water diffusivity, and membrane thickness. We also demonstrate the significance of
Nanoconfined anion exchange membranes (AEMs) play a vital role in emerging electrochemical technologies. The ability to control dominant hydroxide diffusion pathways is an important goal in the design of nanoconfined AEMs. Such control can shorten hydroxide transport pathways between electrodes, reduce transport resistance, and enhance device performance. In this work, we propose an electrostatic potential (ESP) approach to explore the effect of the polymer electrolyte cation spacing on hydroxide diffusion pathways from a molecular perspective. By exploring cation ESP energy surfaces and validating outcomes through prior ab initio molecular dynamics simulations of nanoconfined AEMs, we find that we can achieve control over
Anion exchange membrane fuel cells (AEMFCs) have been regarded as a promising low-cost alternative to proton exchange membrane fuel cells (PEMFCs) due to their potential to utilize platinum group metal (PGM) free catalysts and their recently demonstrated improvement in power density. However, the development of highly active and stable PGM-free electrocatalysts for the hydrogen oxidation reaction (HOR) in alkaline solutions remains a significant challenge. In this study, reactive spray deposition technology (RSDT) is used to fabricate a set of Ni/CeO2/C catalysts, and their activity toward the HOR is investigated as a function of the nanoparticle size. The structural and morphological characterization of as synthesized Ni/CeO2/C catalysts confirms that the RSDT is capable
The availability of durable, high-performance electrocatalysts for the hydrogen oxidation reaction (HOR) is currently a constraint for anion-exchange membrane fuel cells (AEMFCs). Herein, a rapid microwave-assisted synthesis method is used to develop a core–shell catalyst support based on a hydrogenated TiO2/carbon for PtRu nanoparticles (NPs). The hydrogenated TiO2 provides a strong metal-support interaction with the PtRu NPs, which improves the catalyst's oxophilicity and HOR activity compared to commercial PtRu/C and enables greater size control of the catalyst NPs. The as-synthesized PtRu/TiO2/C-400 electrocatalyst exhibits respectable performance in an AEMFC operated at 80 °C, yielding the highest current density (up to 3× higher) within
An ultrathin amine-rich selective layer comprising the fixed-site carrier from polyvinylamine (PVAm) and the mobile carrier with an amino acid salt was successfully coated on top of the polysulfone (PSf) substrate for enhanced CO2-facilitated transport. PVAm with an ultrahigh molecular weight was synthesized via the inverse emulsion polymerization method, which allows the excellent dissipation of the reaction heat and reduces gel formation drastically. Several batches of PVAm with different hydrolysis degrees and molecular weights were successfully synthesized. The mobile carriers of 2-(1-piperazinyl)ethylamine salts of sarcosine (PZEA-Sar) were synthesized and introduced to strengthen the facilitated transport contribution, while cellulose nanocrystals (CNCs)
Despite the recent progress in increasing the power generation of Anion-exchange membrane fuel cells (AEMFCs), their durability is still far lower than that of Proton exchange membrane fuel cells (PEMFCs). Using the complementary techniques of X-ray micro-computed tomography (CT), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) spectroscopy, we have identified Pt ion migration as an important factor to explain the decay in performance of AEMFCs. In alkaline media Pt+2 ions are easily formed which then either undergo dissolution into the carbon support or migrate to the membrane. In contrast to PEMFCs, where hydrogen cross over reduces the ions forming
Considering the worldwide efforts for designing catalysts that are not based on platinum group metals while still reserving the many advantages thereof, this study focused on the many variables that dictate the performance of cathodes used for fuel cells, regarding the efficient and selective reduction of oxygen to water. This was done by investigating two kinds of porous carbon electrodes, modified by molecular cobalt(III) complexes chelated by corroles that differ very much in size and electron-withdrawing capability. Examination of the electronic effect uncovered shifts in the CoII/CoIII redox potentials and also large differences in the affinity of the cobalt center to
The existing gap in the ability to quantify the impacts of resistive losses on the performance of anion-exchange membrane fuel cells (AEMFCs) during the lifetime of their operation is a serious concern for the technology. In this paper, we analyzed the ohmic region of an operating AEMFC fed with pure oxygen followed by CO2-free air at various operating currents, using a combination of electrochemical impedance spectroscopy (EIS) and a novel technique called impedance spectroscopy genetic programming (ISGP). Presented here for the first time in this work, we isolated and quantified the individual effective resistance (Reff) values occurring in the AEMFC
Fuel cell deployable anion exchange membranes (AEMs) constitute some of the cleanest and most affordable electrochemical devices. Elucidation of key design principles underlying these electrolytes requires a fundamental understanding of the effect of different cationic functional groups (FGs) on the performance of an AEM. In this study, we use fully atomistic ab initio molecular dynamics simulations to study the effect of the trimethyl alkyl ammonium (TMA) and imidazolium (IMI) FGs on the hydroxide ions and water diffusivity in AEMs under low hydration conditions using nano-confined structures. The IMI FG was found to be a better chaotropic ion, resulting in a higher water diffusivity.
