Water Transport in Polyelectrolyte Fuel Cells

Alkaline CO2 electrolyzers hold promise for sustainable chemicals and fuels; however, durability challenges, particularly carbonate salt precipitation, hinder their widespread adoption. This study investigates the water and ion transport properties of anion exchange membranes (AEMs) in zero-gap membrane electrode assembly (MEA) configurations, moving beyond the traditional water uptake measurements used in previous CO2 electroreduction literature. The water and potassium transport properties of the three widely used commercial AEMs - PiperION (Versogen), FAA-3 (Fumatech), and Sustainion X37-50RT (Dioxide Materials) - were systematically evaluated using metrics such as water diffusion, transport number, permeability, potassium diffusion, and transference number. Chronopotentiometry was used to identify a critical current density beyond which drying or salt precipitation leads to system failures. Operating at current densities 25% lower than the critical current density significantly extends continuous DC operation from approximately 50 hours to at least 500 hours.Water diffusion and permeability were measured in a liquid-gas cell as a function of membrane thickness. Results indicated Sustainion X37-50RT had the highest water diffusion (3.2 x 10-6 cm2 s-1), followed by PiperION (7.9 x 10-7 cm2 s-1) and FAA-3 (2.9 x 10-7 cm2 s-1). This same trend was observed for water permeation and transport number measurements.Potassium diffusion and transference numbers were measured using a liquid-liquid cell with 0.1M NaHCO3, and 0.1M KHCO3 on each side. Sustainion X37-50RT membranes have the highest potassium diffusion coefficient (6.5 x 10-7 cm2 s-1), followed by FAA-3 (6.0 x 10-8 cm2 s-1) and PiperION (4.5 x 10-8 cm2 s-1). Potassium transference numbers were measured across current densities ranging from 0 to 100 mA cm-2 and held the same trend as the potassium diffusion coefficients.Critical current densities followed the same trend as water diffusion with Sustainion X37-50RT having the highest (180 mA cm-2), followed by PiperION (45 mA cm-2) and FAA-3 (30 mA cm-2). This trend indicates water diffusion to the cathode is crucial to preventing carbonate salt precipitation, especially at increasing current densities. These findings provide fundamental insights for advancing industrial-scale CO2 electrolysis.

Amazing progress has been achieved in the past two years of intensive research on Anion-Exchange Membrane (AEM) Fuel Cells (AEMFCs), bringing this technology significantly closer to the required levels for practical use in automotive (and other) applications. In material-related space, recent studies reported novel techniques for characterizing AEMs for fuel cells [1], as well as robust AEMs with hydroxide conductivities of 300 mS/cm [2]. In addition, new ionomeric materials and functional groups with increasing stability were introduced [3-5], and better Pt-free and PGM-free promising catalysts were developed [6-10]. On the fuel cells front, new AEMFCs based on CRM-free catalysts were successfully demonstrated [11-12], cells with record high power density outputs were obtained [13], materials able to operate under high-temperature AEMFC (HT-AEMFC) operation mode were reported [14], simulated materials and conditions to achieve AEMFC lifetime of 5,000-15,000 hours were theoretical demonstrated [15-16], and cell life time of 2,000 hours of continuous operation was already experimentally proven [17]. Altogether, the research community has made very impressive progress in such a short period of time. Having said that, we are not yet there; several remaining challenges should still be overcome in order to allow this technology to be a serious alternative to the mainstream PEMFC technology. To achieve that goal, we need (A) catalysts with higher activity towards hydrogen oxidation and oxygen reduction reactions to accomplish a full PGM-free (and even CRM-free) AEMFC; (B) a better understanding of carbonation issues while operating AEMFC with ambient air; and, (C) ionomeric materials with higher alkaline stability at higher temperatures. We, at Technion, focus our efforts on these (and other related) research topics, aiming to make a significant impact on the fuel cell research community. The latest achievements of our group in these AEMFC challenging fronts will be presented and discussed during the talk.

An in-depth understanding of liquid water transport in fuel cell gas diffusion layers (GDLs) has the potential to inform the development of novel water management strategies that lead to improved fuel cell performance at high current densities. Several visualization (1-4) and modeling (5, 6) studies have shed light into some of these mechanisms of liquid water transport. However, due to the heterogenous nature of porous materials within the fuel cells, pore-scale modeling and simulations are required for in-depth analysis. Due to recent advancements in visualization techniques, particularly high-resolution synchrotron X-ray (1-4) and neutron (7) micro-computed tomography, the spatial distribution of liquid water within individual GDL pores during fuel cell operation can be resolved. In addition, pore network modeling (8) has been used to simulate and examine pore-to-pore water transport behavior within a wide range of GDL materials. However, we need to combine pore-network simulations with experimental data of realistic fuel cell conditions to study water transport in representative operating conditions in greater detail. In this study, we combined 3-D computed tomography and pore network modeling to expand on our understanding of liquid water transport within gas diffusion layers of operating fuel cells. First, we used synchrotron X-ray tomography to examine the micron-scale GDL porous structure and in-operando 3-D liquid water distribution using a custom fuel cell specialized for imaging. Then, we simulated water transport within the examined GDL structure using pore network modelling. We then compared the 3-D experimental results to our simulations to gain a deeper understanding of realistic inlet conditions for liquid water transport within the GDL. The study demonstrates a robust strategy to probe, understand, and predict liquid water transport within the complex porous structures in PEM fuel cells. References S. J. Normile, D. C. Sabarirajan, O. Calzada, V. De Andrade, X. Xiao, P. Mandal, D. Y. Parkinson, A. Serov, P. Atanassov and I. V. Zenyuk, Meter. Today Energy., 9 (2018).J. Eller, J. Roth, F. Marone, M. Stampanoni and F. N. Büchi, J. Electrochem. Soc., 164, 2 (2017).S. S. Alrwashdeh, I. Manke, H. Markötter, M. Klages, M. Göbel, J. Haußmann, J. Scholta and J. Banhart, ACS Nano., 11, 6 (2017).P. Krüger, H. Markötter, J. Haußmann, M. Klages, T. Arlt, J. Banhart, C. Hartnig, I. Manke and J. Scholta, J.Power Sources., 196, 12 (2011).C. Y. Wang, Chem. Rev., 104 (2004).P. P. Mukherjee, Q. J. Kang and C. Y. Wang, Energy Environ. Sci., 4, 2 (2011).J. M. LaManna, Y. Yue, T. A. Trabold, J. D. Fairweather, D. S. Hussey, E. Baltic and D. L. Jacobson, Meet. Abstr. - Electrochem.Soc., 32 (2017).J. Gostick, M. Aghighi, J. Hinebaugh, T. Tranter, M. A. Hoeh, H. Day, B. Spellacy, M. H. Sharqawy, A. Bazylak, A. Burns, W. Lehnert and A. Putz, Comput. Sci. Eng., 18, 4 (2016).

Effects of fabrication parameters of membrane–electrode assembly for high-performance anion exchange membrane fuel cells

True driving force and characteristics of water transport in osmotic membranes

Anion exchange membrane fuel cells (AEMFCs) have recently attracted significant attention as low-cost alternative fuel cells to traditional proton exchange membrane fuel cells because of the possible use of platinum-group metal-free electrocatalysts. Over the past decade, new materials dedicated to the alkaline medium, such as anion exchange membranes (AEMs) and anion exchange ionomers (AEIs), have been developed and studied in AEMFCs. However, only a few AEMs and AEIs are commercially available, and there are no ready-to-use membrane electrodes assemblies (MEAs) with the desired AEMs and AEIs. Consequently, the need to manufacture in-house CCMs or GDEs becomes a reality that we must face.This work deals with the influence of ionomer content on the prepared MEAs with the commercial anion exchange membrane and ionomer from Aemion™ Ionomr Innovations AF1–HNN8–2 and AP1–ENN8/HNN8 respectively and by varying the support (gas diffusion layer or membrane). The prepared MEAs were characterized morphologically by SEM and profilometry, as well as electrochemically by AEMFC polarization curves and cyclic voltammetry. In addition, an attempt to investigate water management was made with and without a reference electrode in the cell to understand the behavior of water in an operating AEMFC. Our results show that CCM-based MEAs can undergo deformation during the anion conversion step, leading to weakening of the membrane and hence faster degradation in the fuel cell. On the contrary, no deformation was observed for the GDEs during the anionic conversion, although the results are poorer due to (i) poor interface contact between membrane and GDE that depends on ionomer ratio in the ink and (ii) a high overpotential at the anode due to the production of water that cannot be effectively evacuated.

The solution-diffusion model for water transport in reverse osmosis: What went wrong?

Since the 21st century, energy and environmental issues have become the focus of global attention. Traditional fossil energy resources such as oil and natural gas are drying up. Meanwhile, a large number of harmful gases and other pollutants would be produced in the use of traditional energy, which has a serious damage to the environment and climate. With the rapid increase of energy consumption and the need of environmental protection, the demand for clean and efficient energy is growing. Fuel cell (FC) is considered as one of the most promising energy conversion technologies that can replace conventional fossil fuels, and it is also an important choice in the use of hydrogen, methanol, ethanol and other renewable energy. As a new energy with great potential, FC can reduce the energy crisis and environmental pollution effectively by directly converting the chemical energy of the external input fuel into electrical energy and continuously supplying power to the outside. Ion exchange membrane (IEM) is an important component of FC, which is responsible for transferring ions and forming a complete FC circuit. According to the types of conducting ions, IEM can be divided into proton exchange membrane (PEM) and anion exchange membrane (AEM), which are applied to proton exchange membrane fuel cell (PEMFC) and alkaline anion exchange membrane fuel cell (AAEMFC), respectively. Compared with PEMFC, AAEMFC has the advantages of using non noble metal catalyst, high electrode reaction reactivity, and low fuel purity requirements and so on. However, the commercial AEM with organic cations often has low ionic conductivity and poor alkali and dimensional stability, which seriously hinders its development and application in AAEMFC. Therefore, it is urgent to design and develop new high-performance AEM materials. In order to improve the conductivity, alkali stability and dimensional stability of AEMs, a novel reactive bisphenol monomer with pendant dimethylphenoxybenzene group, 1,1-bis (4-hydroxyphenyl)-1-(4-(3,5-dimethylphenoxy) phenyl) phenyl-2,2,2-trifluoroethane ( 2 ), was synthesized based on molecular design using 4-fluoro-2,2,2-trifluoroacetophenone, 3,5-dimethylphenol and phenol as starting materials by a two-step organic reaction. Then, two series of poly(aryl ether sulfone) anion exchange membranes (2-PAES-QA- xx and 2-PAES-Im- xx ) with comb structure were prepared through aromatic nucleophilic copolycondensation, bromination and quaternization reaction based on monomer 2 . The structures of the active bisphenol monomer, the poly(aryl sulfone) containing methyl groups, the brominated poly(aryl ether sulfone)s and the ionized polymers were characterized systematically by nuclear magnetic resonance spectroscopy, respectively. The water uptake, swelling ratio, ionic conductivity, thermal stability, mechanical properties, and alkaline resistance stability of the prepared 2-PAES-QA- xx and 2-PAES-Im- xx membranes were studied in detail. The relationship between the structure and properties of different types of AEMs is further compared. The obtained AEMs showed good overall performance, and the OH– conductivity of these membranes at 60°C is 35.9–51.6 and 32.6–44.9 mS/cm, respectively. The IEC values of the representative 2-PAES-QA-60 and 2-PAES-Im-60 maintained at 79.7% and 88.5% of the initial values after immersion in 4 mol/L NaOH at 80°C for 336 h, respectively. This work provides a new strategy for the design and preparation of comb-type AEM materials.

Next-generation cost-effective anion exchange membrane (AEM) fuel cells (AEMFCs) and AEM water electrolyzers (AEMWEs) have emerged as promising alternatives to costly proton exchange membrane (PEM) fuel cells and water electrolyzers due to the possibility of utilizing platinum-group-metal (PGM)-free catalysts and phasing out unsustainable perfluorosulfonic acid polymers. Anion exchange polyelectrolytes (AEPs), which can be utilized as AEMs or ionomers, are pivotal materials in AEM devices. Despite extensive exploration in the past decade, the application of AEPs has been significantly impeded by their poor ionic conductivity, insufficient alkaline stability, and unfavorable mechanical properties. Therefore, developing highly conductive and robust AEPs is critical to the success of AEMFCs and AEMWEs. (i) Our group has developed a series of highly conductive and durable poly(aryl-co-aryl piperidinium) (c-PAP) AEPs to address the aforementioned issues. c-PAP AEMs and ionomers enable outstanding OH- conductivity (>160 mS cm-1 at 80 °C), alkaline stability (1 M NaOH at 80 °C > 2000 h), dimensional stability, and mechanical properties (tensile strength > 80 MPa), giving them all the properties required for applications in AEM devices. (ii) Based on c-PAP AEMs and ionomers, we have developed high-performance AEMFCs and AEMWEs, as well as provided insights into the ionomer research and the design of membrane electrode assemblies. Typically, c-PAP AEMFCs reached the topmost peak power densities (PPDs) of 2.7 W cm-2 at 80 °C in H2-O2 along with 1000 h cell durability. Moreover, cathode-dried AEMWEs achieved a record-breaking current density of 17 A cm-2 in 1 M KOH, and the cell can be run stably at a 1.5 A cm-2 current density for over 2000 h. The remarkable performances achieved by this new class of c-PAP AEPs identify them as the most promising candidates for practical applications in AEMFCs and AEMWEs. In this account, we will elaborate on our strategies and methodologies associated with c-PAP AEPs and AEM devices, covering the screening and identification of highly durable cation head groups and molecular-engineering approaches to design c-PAP AEMs and ionomers. Moreover, we underscore our strategy in terms of developing highly efficient and durable AEMFCs and AEMWEs. We also elucidate different approaches for further enhancing the ion conductivity and mechanical stability of c-PAP AEMs, including the design of backbones and side chains, cross-linking, and reinforcement. We firmly believe that our series of studies has made substantial contributions to the fields of AEM, ionomers, AEMFCs, and AEMWEs, which have advanced AEM technology to be on par with PEM technology, opening a new avenue for commercialization of AEMFCs and AEMWEs.

Low cost and high durability are considered as the main challenges in mass scale commercialization of the low temperature fuel cells. Anion exchange membrane fuel cells (AEMFC’s) have attracted tremendous attention because of their promising characteristics to overcome some of the critical problems associated with proton exchange membrane fuel cells. The main advantages of AEMFC´s are possibility of using cheaper non-noble metal catalyst, lower crossover of cationic redox couples, facile reaction kinetics. In recent years, nitrogen-doping of carbon materials has been used to achieve active non-platinum catalyst.1,2 However it has been reported that the presence of transition metals such as Co or Fe can further enhances the electrocatalytic properties of N-doped carbons.3 The main goal of this study was to develop highly active transition metal-nitrogen co-doped catalyst as alternative cathode material to Pt/C in AMFC. A simple synthesis method was used to receive nitrogen doped multi-walled carbon nanotube supported CoCl2 catalyst material (Co/N-MWCNT). MWCNT treated in a concentrated HNO3-H2SO4 mixture were used as carbon support. MWCNTs were first dispersed in ethanol by sonication, after which dicyandiamide as the nitrogen source and Co salt were added along with a dispersing agent. The mixture was then heat-treated at 800 °C for 2 h in a tube furnace. Polished glassy carbon electrodes were modified with a dispersion containing the resulting materials and Tokuyama OH−ionomer AS-04. The rotating disk electrode (RDE) measurements were performed in 0.1 M KOH. The stability of the catalysts were also tested using RDE method. The structural and compositional properties of the catalyst material were defined by X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The oxygen reduction reaction (ORR) has been studied on Co/N/MWCNT electrocatalyst modified GC electrodes in 0.1 M KOH using the RDE method. The fuel cell performance of Co/N/MWCNT cathode catalyst material was investigated by fabricating membrane-electrode assemblies (MEAs) using Tokuyama membrane (# A201). The RDE results indicated excellent electrocatalytic properties of Co/N-MWCNT material toward oxygen electroreduction in alkaline media. The comparative study of Co/N-MWCNT with commercial Pt/C catalyst showed fair catalytic activity of our non-platinum catalyst in 0.1M KOH and significant enhancement of the ORR was observed in comparison to unmodified MWCNTs. The number of electrons transferred per oxygen molecule (n) at different potentials for the Co/N-MWCNT modified GC electrode was calculated from the KouteckyLevich equation. The value of n for the Co/N-MWCNT material was 4 over the whole range of potentials studied. The fuel cell performance was investigated with Co/N-MWCNT cathode catalyst and Tokuyama A201 anion exchange membrane. AEMFC performance was evaluated and compared at different temperatures up to 50 ⁰C. Maximum power density with H2/O2 gases at ambient pressure was ~115 mWcm-2. The fuel cell perfomance of the Co/N-MWCNT catalyst was also compared with the perfomance of the commercial Pt/C and cobalt phthalocyanine modified MWCNT catalysts (Fig.1).

The understanding of water transport in graphene oxide (GO) membranes stands out as a major theoretical problem in graphene research. Notwithstanding the intense efforts devoted to the subject in the recent years, a consolidated picture of water transport in GO membranes is yet to emerge. By performing mesoscale simulations of water transport in ultrathin GO membranes, we show that even small amounts of oxygen functionalities can lead to a dramatic drop of the GO permeability, in line with experimental findings. The coexistence of bulk viscous dissipation and spatially extended molecular friction results in a major decrease of both slip and bulk flow, thereby suppressing the fast water transport regime observed in pristine graphene nanochannels. Inspection of the flow structure reveals an inverted curvature in the near-wall region, which connects smoothly with a parabolic profile in the bulk region. Such inverted curvature is a distinctive signature of the coexistence between single-particle zero-temperature (noiseless) Langevin friction and collective hydrodynamics. The present mesoscopic model with spatially extended friction may offer a computationally efficient tool for future simulations of water transport in nanomaterials.

Controlling the synthesis parameters during radiation-induced grafting (RIG) is a key feature to design anion-exchange membranes (AEMs) with enhanced properties that lead to high performances and stability. The present study provides a systematic investigation of the effect of RIG methods on physicochemical properties of LDPE-based AEMs with similar degree of grafting (DoG) and ion exchange capacity (IEC). The LDPE films were grafted with 4-vinylbenzyl chloride using two methods: i) pre-irradiation (PIM), using electron-beam (EB), and ii) simultaneous (SM), using gamma-ray (γ), both in air atmosphere and with different absorbed doses. The AEMs grafted by SM were irradiated with 20, 25, and 30 kGy, while the ones grafted by PIM were irradiated with doses of 30, 70, and 100 kGy. Samples grafted by the two different methods have the same molecular structure, but distinct physicochemical properties due to markedly differences in the degree of crosslinking. The studies have shown that grafting step directly influences the internal structure and morphology of AEMs. Multi-technique characterization demonstrated that RIG method determines the mechanical properties, water transport, and the distribution of ionic groups in AEMs. These characteristics have direct impact on fuel cell performance, anion-conductivity, and AEM stability.Figure 1 shows the polarization curves of anion-exchange membrane fuel cells (AEMFCs) operating at 80 °C with AEMs grafted by PIM and SM. Comparing AEMFCs performances containing AEMs with similar IECs from the two different grafting methods, it is possible to notice that AEMs synthesized by PIM, in general, promote better fuel cell performances than the corresponding ones prepared by SM. The main differences in the polarization curves are evidenced in the ohmic and the mass transport limiting regions. This result suggests that water management is enhanced in AEMs synthesized by PIM compared to the SM-AEMs. A membrane that allows rapid back diffusion of liquid water from the anode to the cathode, should reduce the current losses due to mass transport limitations.The gel content results confirmed the presence of more crosslinking in membranes synthesized by PIM than in the ones synthesized by the SM. As a consequence of that, enhanced mechanical properties were found for PIM-AEMs, indicating polymer backbone reinforcement due to high degree of crosslinking. Small-angle X-ray scattering measurements have confirmed that the microstructure of PIM and SM AEMs are different and this feature is directly related to ion conduction and water transportation.Figure 1. AEMFCs performances at 80 °C with LDPE-based AEMs grafted by the pre-irradiation method and by the simultaneous method. H2 anode gas flow=0.8 L min-1, O2 cathode gas flow=0.5 L min-1, both supplied unpressurized with optimal dewpoint temperatures ranging from 77 to 80 °C. AEMs are referred according to the grafting method and absorbed dose. 30 and 70-EB-PIM refer to the samples irradiated with 30 and 70 kGy, respectively, in the EB accelerator and grafted by the pre-irradiation method. 20 and 25-γ-SM refer to AEMs irradiated with 20 and 25 kGy, respectively, by γ-rays and grafted by the simultaneous method. Figure 1

With the recent developments of high-performance anion-exchange membranes (AEM), there has been an increased interest towards studying various electrochemical reactions such as ethanol electrooxidation, hydrogen oxidation reactions and oxygen reduction reactions in AEM fuel cells (AEMFC). This increased attention has been attributed to the faster electro oxidation kinetics, increased stability and lower poisoning of the catalysts in alkaline media. And since AEMFCs are not limited to platinum - unlike in proton exchange membrane fuel cells (PEMFCs) with highly acidic environments - intensive efforts towards developing alternatives such as palladium (Pd) and Pd-based alloys are currently underway.1 , 2 Various studies have shown the enhanced stability and higher activities of Pd-based catalysts compared to Pt in alkaline medium using potentiodynamic and potentiostatic techniques. However, there are only a limited number of studies that have investigated the performance of Pd-based electrocatalysts in AEMFCs. Also, majority of these studies have demonstrated relatively low performances in AEMFCs, mainly due the complications associated with forming the triple-phase boundary (TPB) structure in the membrane layer, where reactions are taking place in the electrolyte, gaseous fuel and electrode interface. The density of the TPB, along with the intrinsic activities of the catalysts can play an important role in determining the overall performance of AEMFCs. Moreover, Pd-based are usually synthesized using surfactants, organic stabilizers or reducing agents, that can get adsorbed onto the surface of Pd and inhibit ionomer-catalyst-fuel interactions in the TPB. To mitigate the limitations associated with TPB structure and subpar catalyst activities, macroporous three-dimensional Graphene nanosheet (3D-GNS) supports with controlled morphologies and porosities were fabricated by utilizing silica sacrificial templates.3 The sacrificial templates were then etched to leave a network of porous channels within its matrix, and utilized as supports for Pd nanoparticles. The porous structure of these highly graphitized 3D-GNS supports can facilitate mass-transport kinetics by enabling the ionomer and polymer electrolyte getting the reactants to get catalyzed by Pd nanoparticles. Also, to enhance ionomer-nanoparticle interactions, the Pd nanoparticles of an average size of 3-5 nm were synthesized using a previously established surfactant-free soft alcohol reduction method.4 In this study, anion exchange catalyst-coated membranes (CCMs) were prepared using Pd nanoparticles supported on both commercial carbon blacks (Vulcan) and 3D-Graphene supports as both cathode and anode catalyst in H2/O2 fed AEMFCs. The Pd catalyst inks were prepared by mixing the dispersed Pd-catalyst in an optimized solution of isopropyl alcohol and quaternary ammonium-functionalized AS4 ionomer. The inks were then applied onto an anion exchange membrane (A201, Tokuyama) with an active area of 5 cm2. The CCMs was then hydrated in 0.5 M KOH for 24 hours, followed by rinsing in de-ionized water for 24 hours. It was then sandwiched between gas diffusion layers and annealed with gaskets by pressing under 500 psi for 5 minutes. The cell was then assembled and activated by operating at 0.3V at 60ºC for 10 minutes under humidified O2 and H2, followed by the measuring the polarization curves. Preliminary results show that Pd nanoparticles synthesized using surfactant-free method SARM and deposited on commercial carbon supports have and OCV of 0.95 V and a peak power output of 200 mWcm-2. These results already show the promising potential of using surfactant-free non-alloyed monometallic Pd nanoparticles. Further tests will also be performed to show the effect of porous 3D-Graphene supports towards modifying the TPB interphase and its effects on MEA performance in both Ethanol/O2 and H2/O2 fed AEMFCs. The results from this study will not only contribute towards the development of Pt-free oxidative and reductive electrocatalysts, but also lead to further advancements in AEMFC technology that will enable it to operate with other fuels such as methanol and hydrazine.

Aiming the water transport issues of anion exchange membrane fuel cells by introducing hydrophobic carbon nanotube diffusion layer

Fuel cells have lately received growing attention since they allow the use of non-precious metals as catalysts, which reduce the cost per kilowatt of power in fuel cell devices to some extent. Until recent years, the major barrier in the development of fuel cells was the obtainability of highly conductive anion exchange membranes (AEMs). On the other hand, improvements show that newly enhanced anion exchange membranes have already reached high conductivity levels, leading to the suitable presentation of the cell. Currently, an increasing number of studies have described the performance results of fuel cells. Much of the literature reporting cell performance is founded on hydrogen‒anion exchange membrane fuel cells (AEMFCs), though a growing number of studies have also reported utilizing fuels other than hydrogen—such as alcohols, non-alcohol C-based fuels, and N-based fuels. This article reviews the types, performance, utilized membranes, and operational conditions of anion exchange membranes for fuel cells.