Aryl ether-free polymer electrolytes for electrochemical and energy devices

Chemical Society Reviews, Journal Year: 2024, Volume and Issue: 53(11), P. 5704 - 5780

Published: Jan. 1, 2024

This review provides a depth of knowledge on the synthesis, properties and performance aryl ether-free anion exchange polymer electrolytes for electrochemical energy devices.

Language: Английский

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Nickel-Based Anode Catalysts for Efficient and Affordable Anion-Exchange Membrane Fuel Cells

Accounts of Chemical Research, Journal Year: 2023, Volume and Issue: 56(12), P. 1445 - 1457

Published: May 11, 2023

ConspectusLow-temperature ion-exchange membrane hydrogen fuel cells, as zero-emission power sources, can largely preserve the merits of gasoline engines, including rapid fueling, extended cruising range, and low maintenance cost. To enable widespread prevalence fuel-cell automobiles, U.S. Department Energy (DOE) has set a long-term system cost target US$30 kW-1. Over past decades, proton-exchange cell (PEMFC) technology developed rapidly, resulting in first commercial sales fuel-cell-powered vehicles. Although there been great success, mass market penetration PEMFCs is currently hindered by excessive reliance on expensive platinum group metal (PGM) catalysts. Anion-exchange cells (AEMFCs), because alkaline environment that permits use PGM-free catalysts, have become an alternative with inherent advantages. Thus far, significant progress made exploration catalysts for oxygen reduction reaction at AEMFC cathode, some which shown intrinsic catalytic properties comparable to PGM However, development anodic oxidation (HOR) lagged behind, presumably owing its sluggish kinetics alkali. In media, HOR about 2 orders magnitude slower than acid, demands higher loadings reach similar performance PEMFCs. Since Raney nickel (Ni) was explored catalysis 1960s, research Ni-based begun now flourishing, primarily thanks their favorable adsorption energies key intermediates (e.g., Ni-Had Ni-OHad). At present, number strategies improve performances materials, such alloying, Ni nitridation, alloy amorphization, yield cost-effective rival or even exceed activity stability counterparts.In this Account, we describe our recent endeavors toward efficient practical anodes. First, briefly highlight important why materials are appealing catalysis. Critical innovations design nanostructured bulky were then discussed, showing promise catalyze traditionally relied PGMs. demonstrate utility, elaborately designed under realistic conditions examined, along initial effort develop CO-tolerant anode. We conclude outlining future directions allow access next-generation advanced AEMFCs.

Language: Английский

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Dynamic Electrodeposition on Bubbles: An Effective Strategy toward Porous Electrocatalysts for Green Hydrogen Cycling

Accounts of Chemical Research, Journal Year: 2023, Volume and Issue: 56(12), P. 1421 - 1432

Published: May 25, 2023

ConspectusClosed-loop cycling of green hydrogen is a promising alternative to the current hydrocarbon economy for mitigating energy crisis and environmental pollution. It stores from renewable sources like solar, wind, hydropower into chemical bond dihydrogen (H2) via (photo)electrochemical water splitting, then stored can be released on demand through reverse reactions in H2-O2 fuel cells. The sluggish kinetics involved half-reactions evolution reaction (HER), oxygen (OER), oxidation (HOR), reduction (ORR) limit its realization. Moreover, considering local gas-liquid-solid triphase microenvironments during H2 generation utilization, rapid mass transport gas diffusion are critical as well. Accordingly, developing cost-effective active electrocatalysts featuring three-dimensional hierarchically porous structures highly desirable promote conversion efficiency. Traditionally, synthetic approaches materials include soft/hard templating, sol-gel, 3D printing, dealloying, freeze-drying, which often need tedious procedures, high temperature, expensive equipment, and/or harsh physiochemical conditions. In contrast, dynamic electrodeposition bubbles using situ formed templates conducted at ambient conditions with an electrochemical workstation. whole preparation process finished within minutes/hours, resulting employed catalytic electrodes directly, avoiding use polymeric binders Nafion consequent issues limited catalyst loading, reduced conductivity, inhibited transport.In this Account, we summarize our contributions toward advanced cycling. These electrosynthesis strategies potentiodynamic that linearly scans applied potentials, galvanostatic fixes currents, electroshock quickly switches potentials. range transition metals alloys, nitrides, sulfides, phosphides, their hybrids. We mainly focus porosity design by tuning parameters tailor behaviors bubble co-generation thus interface. Then, electrocatalytic applications HER, OER, overall splitting (OWS), biomass (to replace OER), HOR introduced, special emphasis porosity-promoted activity. Finally, remaining challenges future perspective also discussed. hope Account will encourage more efforts attractive research field various carbon dioxide/monoxide reduction, nitrate methane oxidation, chlorine evolution, others.

Language: Английский

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The need for ion-exchange membranes with high charge densities

Journal of Membrane Science, Journal Year: 2023, Volume and Issue: 677, P. 121608 - 121608

Published: March 23, 2023

Language: Английский

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Quaternary Ammonium-Functionalized Polyethylene-Based Anion Exchange Membranes: Balancing Performance and Stability

ACS Energy Letters, Journal Year: 2023, Volume and Issue: 8(5), P. 2365 - 2372

Published: April 21, 2023

Anion exchange membrane water electrolyzers (AEMWEs) and fuel cells (AEMFCs) require an anion (AEM) with high hydroxide ion conductivity chemical stability to oxidative alkaline conditions. Herein the conductivities of 17 quaternary ammonium-functionalized polyethylene-based AEMs were measured over time understand influence ammonium functional groups on AEM performance. The piperidinium-based containing a β-methyl in backbone resulted 41 mS/cm at 22 °C highest 95% retention after 30 days 1 M KOH 80 °C. In cell tests, increasing capacity led increased performance from peak power density 0.7 1.0 W/cm2, enabling it compete other state-of-the-art optimization.

Language: Английский

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