Abstract The primary function of the ionomers that are incorporated into fuel cell electrode catalyst layers is to provide pathways for ion transport between active sites and electrolyte. This influenced by many variables, including ion‐exchange capacity, water uptake, molecular weight. In anion exchange membrane cells (AEMFCs), controlling ionomer uptake particularly important tailoring this property in each an consideration when looking maximize performance. study, three poly(norbornene)...

Alkaline fuel cells and electrolyzers are of interest because they have potential advantages over their acid counterparts. High-conductivity anion conducting membranes were analyzed used in alkaline hydrogen/oxygen cells. The composed reinforced block copolymers poly(norbornenes) with pendant quaternary ammonium head-groups. It was found that light cross-linking provided excellent mechanical stability allowed very high ion exchange capacity polymers to be without penalty excessive water...

High ionic conductivity membranes can be used to minimize ohmic losses in electrochemical devices such as fuel cells, flow batteries, and electrolyzers. Very high hydroxide was achieved through the synthesis of a norbornene-based tetrablock copolymer with an ion-exchange capacity 3.88 meq/g. The were cast thin polymer reinforcement layer lightly cross-linked N,N,N',N'-tetramethyl-1,6-hexanediamine. norbornene had 212 mS/cm at 80°C. Light cross-linking helped control water uptake provide...

Cross-linked (XL) anion-exchange membranes (AEMs) synthesized by vinyl addition polymerization of norbornene were prepared for use in membrane electrochemical devices, including fuel cells and electrolyzers. Tetrablock copolymers composed an all-hydrocarbon backbone with a very high ion-exchange capacity (IEC), 3.46 mequiv/g, synthesized. Light cross-linking was found to be adequate providing critical control over unwanted water uptake. This enabled IEC membranes. Without light...

A systematic comparison between random and block copolymer membrane properties showed the suitability of membranes.

A series of cross-linked (XL) anion-exchange membranes (AEMs) were synthesized on the basis ring opening metathesis polymerization (ROMP) norbornene monomers (rPNB). Poly(bromopropyl norbornene)-block-poly(butyl norbornene) diblock copolymers and poly(bromopropyl homopolymers have an all-hydrocarbon backbone a high ion-exchange capacity (IEC), up to 4.73 mequiv/g. N,N,N′,N′-Tetramethyl-1,6-hexanediamine (TMHDA) was used as cross-linking agent control water uptake mechanical instability. The...

Water electrolysis using an anion conductive, solid polymer electrolyte is attractive method for point-of-use hydrogen production. Recent advances in catalysts and exchange membranes (AEM) have made alkaline devices increasingly competitive with their acidic counterparts. However, less attention has been paid to the conductive ionomers (ACI) used fabrication of electrodes AEM electrolyzers. The ACI contributes ion conduction between catalyst bulk serves as a binder adhering gas diffusion...

Green hydrogen produced through anion exchange membrane water electrolysis is a promising, low-cost chemical storage solution for intermittent renewable energy sources. Low-temperature using membranes (AEM) combines the benefits of established technologies based on alkaline and proton electrolysis. The conductive ionomers (ACI) used in AEM electrolyzer (AEMEL) electrodes has been investigated. ACI serves two primary purposes: (i) facilitate hydroxide conduction between catalyst bulk...

Multiblock copolymers with different number of head-group tethers were compared as AEMs for high ionic conductivity and good alkaline stability.

Direct borohydride fuel cells (DBFCs) can operate at double the voltage of proton exchange membrane (PEMFCs) by employing an alkaline NaBH4 feed and acidic H2O2 oxidant feed. The pH-gradient-enabled microscale bipolar interface (PMBI) facilitates creation maintenance environment anode cathode for oxidation peroxide reduction reactions. However, given need to dissociate water ensure ionic conduction, PMBI be efficient only when anion ionomer (AEI) moieties enable fast transport...

The design of new anion exchange ionomers for use in electrochemical devices is a critical step improvement anionic fuel cells and electrolyzers. Although these materials share some targeted goals with membranes (AEMs), there are several different property requirements. Since used within electrode layers, they do not serve as primary separator air. Rather, act transport facilitator the where high degree mass required. In this study, series synthesized tested hybrid AEM These based on which...

Anion exchange membrane fuel cells (AEMFCs) have been widely touted as a low-cost alternative to existing proton cells. However, AEMFCs operating on air suffer from severe performance penalty caused by carbonation exposure CO 2 . Many approaches removing the cathode inlet would consume valuable energy and complicate systems-level balance-of-plant. Therefore, this work focuses an electrochemical solution where removal still generate power, but not expose entire AEMFC stack conditions. Such...

Correction for ‘Poly(norbornene) anion conductive membranes: homopolymer, block copolymer and random properties performance’ by Mrinmay Mandal <italic>et al.</italic>, <italic>J. Mater. Chem. A</italic>, 2020, DOI: 10.1039/d0ta04756b.

Electrochemical devices, such as fuel cells and electrolyzers, which operate under alkaline conditions, are of interest because they have reduced platinum usage certain performance advantages. New improved anion conducting membranes (AEM) been developed. It is desirable for AEMs to high molecular weight low oxygen or permeability. The ionomers used make the electrodes electrolyzers share some properties with membranes, chemical stability ionic conductivity. However, differ from in other...

Fuel cells based on alkaline exchange membranes (AEM) have garnered increased interest because of their inherent advantages over traditional proton (PEM). High pH operating conditions allow for more facile reaction kinetics, reduced platinum-group metal catalyst, and fuel crossover issues. Moreover, these materials can be made from inexpensive precursors which further drive down the cost membrane electrode assemblies (MEA) cells. In this study, a variety block copolymer AEMs vinyl addition...

Anion-exchange membranes (AEMs) have widespread applications in electrochemical devices. The development of AEMs with long-term alkaline stability and high hydroxide ion conductivity is currently interest. use non-precious catalysts, facile reaction kinetics reduced fuel crossover are some the benefits over proton-exchange (PEMs). However, present limitations include low ionic conductivity, poor at pH, water uptake. A series multiblock copolymers based on vinyl addition ring-opening...

The conductivity and physical properties of the ion conductive channels in a multiblock copoly(arylene ether) polymer was quantitatively measured as function (i) number tethered head-groups per repeat unit (ii) type cation head-groups. Multiblock ether)s with 1, 2, 3 4 alkyl chain quaternary ammonium on each hydrophilic were synthesized via polycondesation, Friedel-Crafts, reduction reactions, Figure 1. effect ionic groups exchange capacity (IEC), morphology anion membranes investigated. As...

While research and development has been focused primarily on proton exchange membrane (PEM) devices in recent decades, based anion membranes (AEM) have garnered increased interest as a potential cost-saving alternative. To be viable for use electrochemical devices, AEMs must good long-term alkaline thermal stability, high hydroxide ion conductivity, lower water uptake, molecular weight, low oxygen or fuel permeability. Polar groups the polymer backbone are susceptible to nucelophilic attack...

Alkaline exchange membrane (AEM) fuel cells are an alternative to more conventional proton (PEM) and electrolyzers. In recent years, anion conducting polymer membranes have achieved stability ionic conductivity competitive with Nafion. Lightly cross-linked AEMs based on vinyl addition polymerized norbornene record-high hydroxide (212 mS/cm) &lt;1% performance degradation over 1,200 hours in 1 M NaOH at 80 °C. Composite versions of these also been used construct electrode assemblies for...

Alkaline exchange membranes (AEM) fuel cells and electrolyzers are potentially cost-saving alternatives to traditional proton membrane (PEM) devices. Recently, anion conducting polymer have achieved ionic conductivity chemical stability comparable Nafion, the current state of art in PEM technology. Phase segregation is an effective way achieving high hydroxide mobility. An all-carbon backbone with light cross-linking a long, alkyl tether for cation head-group means limiting unwanted water...

Block copolymer, anion-exchange membranes (AEM) were synthesized using the vinyl-addition polymerization and ring-opening metathesis of norbornene monomers. The intended use is for electrochemical devices operating at high pH including fuel cells, electrolyzers, flow batteries. focus this talk on impact very conductivity AEM with low water uptake device performance. molecular weight monomers enabled design ion exchange capacity (IEC) membranes, up to 4.73 meq/g. A wide variety are available...

Anion-exchange membranes (AEMs) are used in electrochemical energy storage and conversion devices such as batteries, fuel cells, electrolyzers. The development of AEMs with long-term alkaline stability high anion conductivity (i.e. hydroxide, carbonate bicarbonate) is current interest. benefits over proton-exchange membrane (PEM) include the use non-precious catalysts, facile reaction kinetics, reduced crossover. However, issues low ionic conductivity, poor at pH, water uptake need to be...

Hydrogen today is mainly produced by steam reforming natural gas or other fossil fuels. However, this method produces low purity hydrogen with a high concentration of carbonaceous species and ultimately does not relieve dependencies on fuels reduce harmful greenhouse gasses. production from water electrolysis low-carbon carbon-free alternative to can be utilized as chemical means storing excess energy intermittent sources such wind solar. Solid polymer electrolyte based anion exchange...