Anion exchange membranes (AEMs) find widespread applications as an electrolyte and/or electrode binder in fuel cells, electrodialysis stacks, flow and metal-air batteries, electrolyzers. AEMs exhibit poor stability alkaline media; their degradation is induced by the hydroxide ion, a potent nucleophile. We have used 2D NMR techniques to investigate polymer backbone (as opposed cation stability) of AEM media. report mechanism behind peculiar, often-observed phenomenon, wherein demonstrably...

The development of alkaline fuel cells over the past decade has led to exciting developments in low resistant and stable anion exchange membranes (AEMs). This Review highlights new material chemistries macromolecular designs that have fueled AEMs with ionic conductivities greater than 100 mS cm–1, while demonstrating stability for extended periods base bath solutions 1 M potassium (or sodium) hydroxide at temperature 80 °C or greater. AEM (AEMFCs) power density values exceed W cm–2 hydrogen...

Hydrogen holds great promise as a clean energy resource to help the global carbon-free goal. Green hydrogen production from renewable energy-powered water electrolysis can decarbonize hard-to-abate industries and transport applications. Ion-exchange membranes are an essential component of membrane-based electrolysis, enabling high efficiency through zero-gap configuration. While perfluorosulfonic acids standard polymer electrolyte membrane material, research efforts for alternatives have...

Polysulfone (PSF) backbones were functionalized with reactive chloromethyl groups for preparing thin film anion exchange membranes (AEMs) fixed benzyl quaternary cations. Three different cation chemistries of varying basicity evaluated: 1,4-dimethylpiperazinium (DMP+), trimethylammonium (TMA+), and trimethylphosphonium (TMP+). The water uptake, ionic conductivity, stability in alkaline media these AEMs assessed both chloride hydroxide counteranions. results obtained revealed that the value...

Solid-state alkaline water electrolysis using a pure feed offers several distinct advantages over liquid electrolyte and proton exchange membrane electrolysis. These include larger array of electrocatalyst available for oxygen evolution, no management, the ability to apply differential pressure. To date, there have been only handful reports on solid-state electrolyzers anion membranes (AEMs), that investigate loss in system performance time. In this work, electrolyzer was successfully...

A fluorescent molecular probe, 6-carboxy fluorescein, was used in conjunction with situ fluorescence spectroscopy to facilitate real-time monitoring of degradation inducing reactive oxygen species within the polymer electrolyte membrane (PEM) an operating PEM fuel cell. The key requirements suitable probes for ROS are presented. utility using free radical scavengers such as CeO 2 nanoparticles mitigate induced demonstrated. addition uncatalyzed membranes resulted close 100% capture generated...

Fuel cells based on the anodic exchange membranes (AEMFC) can operate a variety of fuels and generate high power densities at moderate operating temperatures. The real advantage AEMFC use in polymer-electrolyte membrane fuel is absence expensive noble metal catalysts electrodes. However, systems have their own set challenges, as related to materials processing schemes, which require innovative engineering solutions. Key among these are conductivity durability anion-exchange membrane,...

A polysulfone-based anion exchange membrane functionalized with quaternary benzyl trimethylammonium groups (PSF-TMA+) demonstrated a 40-fold reduction in vanadium(IV) permeability when compared to Nafion® membrane. Comprehensive 2D NMR (COSY and heteronuclear quantum correlation spectroscopy) studies verified that PSF-TMA+ remained chemically stable even after exposure 1.5 M vanadium(V) solution for 90 days. Excellent energy efficiencies (85%) were attained sustained over several...

Alkaline fuel cells containing anion exchange membrane electrolytes (i.e., solid-state alkaline - SAFCs) promise to provide high power densities without platinum group metal catalysts. In the past decade, SAFC performance has improved substantially due improvements in electrode binders that facilitate good membrane-electrode contact and ionic conductivity layer. However, (in)stability of AEMs is a long-standing challenge currently precludes commercialization this technology. To date, there...

Low temperature anion exchange polymer electrolyte membrane (AEM) based fuel cells and electrolyzers have been successfully shown to convert hydrogen oxygen electricity (and vice-versa) with high efficiencies energy densities non-precious group metals. However, a significant challenge realizing these technologies is the poor alkaline stability of AEMs. In this work, we present results our multi-faceted approach better understand AEM degradation in media. Several two-dimensional (2D) NMR...

Membrane capacitive deionization (MCDI) has emerged as an effective and energy efficient desalination technology for treating brackish water streams used in numerous industrial processes. Most material research studies on MCDI focus improving the porous electrodes or using flowing electrode architectures, little emphasis is given to rationale design of ion-exchange membranes (IEMs) MCDI. In this work, ionic conductivity, permselectivity, thickness three different IEM chemistries...

Electrochemical properties of most supercapacitor devices degrade quickly when the operating temperature deviates from room temperature. To exploit potential rGO in supercapacitors at extreme temperatures, a resilient electrolyte that is functional over wide range also required. In this study, we have implemented flexible, low-resistant solid-state membrane (SSEM) into symmetric electrodes to realize operate −70 220 °C. The SSEM consists polycation–polybenzimidazole blend doped with...

Ion conducting block copolymers can overcome traditional limitations of homopolymer electrolytes by phase separating into nanoarchitectures that be simultaneously optimized for two or more orthogonal material properties such as high ionic conductivity and mechanical stability. A key challenge in understanding the ion transport these materials is difficulty extracting structure-function relationships without having complete knowledge all nanoscale pathways bulk samples. Here we demonstrate a...

Intermediate-temperature polymer electrolyte membrane fuel cells (IT-PEMFCs), operating with phosphoric acid (H3PO4) doped polybenzimidazole (PBI), are severely limited by H3PO4 evaporation at high temperatures and poor resiliency in the presence of water. Polycations (PCs), on other hand, provide good retention due to strong ion-pair interactions but have low conductivity lower ion-exchange capacity when compared PBI. In this work, a class PC–PBI blends was prepared, optimal blend (50:50...

Thermally regenerative batteries (TRBs) is an emerging platform for extracting electrical energy from low-grade waste heat (T < 130 °C). TRBs using ammonia-copper redox couple can store waste-heat in a chemical form that be later discharged to upon demand. Previous thermally ammonia battery (TRAB) demonstrations suffered poor conversion efficiency when benchmarked against thermoelectric generators (TEGs). In this work, we report the highest power density date TRAB (280 W m–2 at 55 °C) with...

Conventional hydrogen separations from reformed hydrocarbons often deploy a water gas shift (WGS) reactor to convert CO CO2, followed by adsorption processes achieve pure hydrogen. The purified is then fed compressor deliver at high pressures. Electrochemical pumps (EHPs) featuring proton-selective polymer electrolyte membranes (PEMs) represent an alternative separation platform with fewer unit operations because they can simultaneously separate and compress continuously. In this work,...

Per- and polyfluoroalkyl substances (PFASs) pose a significant health threat to humans at trace levels. Because of its ubiquity across the globe, there have been intense efforts rapidly quantify PFASs in environment while also mitigating their release. This work reports an electrochemical sensor with selective perfluorinated anion exchange ionomer (PFAEI) coating for direct sensing perfluorooctanoic acid (PFOA)-a type PFAS. Notably, operates without need redox probes has limit detection...

Aromatic acids, such as p-coumaric acid, are valuable chemical intermediates that used in the specialty industries because they precursors to phenylpropanoid compounds. The separation of acid from fermentation broths is a critical step biochemical production process and more broadly circular carbon economy. Electrodeionization (EDI) has been applied toward separations low-carbon chain but purifying challenging due fouling irreversible binding with ion-exchange membranes resins. Here, we...

Plasma protein therapies are used by millions of people across the globe to treat a litany diseases and serious medical conditions. One challenge in manufacture plasma is removal salt ions (e.g., sodium, phosphate, chloride) from solution. The conventional approach remove use diafiltration membranes tangential flow filtration) ion-exchange chromatography. However, resins within chromatographic column as well filtration subject fouling protein. In this work, we investigate membrane capacitive...

A perfluorinated anion exchange membrane with a 1,4-dimethylpiperazinium cation demonstrated better hydroxide ion conductivity and three-fold reduction in water uptake compared to hydrocarbon AEM the same cation. The was stable over 30 days 2 M KOH at 60 °C good fuel cell performance.

The alkaline stability of poly(arylene ether) backbones in anion exchange polymer electrolyte membranes (AEMs) derivatized with quaternary benzyl N, N- dimethylhexylammmonium (DMH+) and trimethylammonium (TMA+) cation groups were investigated poly(2,6-dimethyl 1,4-phenylene) oxide (PPO) Udel polysulfone (PSF) polymers. Previous studies have demonstrated that ammonium phosphonium trigger backbone degradation commercially available ether)-based AEMs, despite the base polymers being resilient...

Porous separators are key components for lithium-ion batteries (LIBs) and they have drawn considerable attention because of their vital role in governing battery cost performance (e.g., power density, safety, longevity). Here, zirconia-coated were fabricated via a facile biomineralization process with the aim to improve commercialized polypropylene separators. The as-prepared organic-inorganic composite show excellent thermal stability, even at melting temperature (160 °C) polypropylene....