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• Composite sulfur host coupled with porous current collector for Li-S batteries. • Fe single-atom decorated hollow mesoporous carbon spheres. • Composited with free-standing carbon cloth supported CoS X nanowire arrays. • High initial capacity of 1430 mAh g −1 at 0.1 C and 588 mAh g −1 maintained at 2 C. • Ultralow capacity decay rate of 0.029 % per cycle over 600 cycles at 1 C. Lithium-sulfur batteries (LSBs) are a promising next generation electrochemical energy storage device. Its commercialization however is hindered by several technical challenges, particularly shuttling of polysulfides. A composite sulfur host, coupled with a porous current collector, was developed to mitigate the shuttling problem. Iron single atom (SAFe) decorated hollow mesoporous carbon spheres (HMCS), composited with cobalt sulfide nanowire arrays supported on free-standing carbon cloth (S-Co@CC), were fabricated as a high-performance sulfur host for LSBs. The sulfur host combines the high electrical conductivity and physical confinement capability of HMCS, the excellent polysulfides chemisorption capability of cobalt sulfide nanowire arrays, and the high catalytic efficiency of iron single atoms toward polysulfide conversion reactions, to achieve a high-performance LSB. The S-Co@CC/SAFe-HMCS based LSB exhibited a high initial specific capacity of 1430 mAh g −1 at 0.1 C. For cycling stability, a specific capacity of 578 mAh g −1 was maintained after a 600-cycle operation at 1 C, achieving an ultralow average capacity decay rate of 0.029 % per cycle. The design of composite sulfur hosts, combining all functional components in one, proves to be an effective strategy to advance the development of high-performance LSBs. Iron single-atom (SAFe) decorated hollow mesoporous carbon spheres (HMCS) composited with freestanding carbon cloth supported cobalt sulfide nanowire arrays (S-Co@CC) were fabricated as a highperformance sulfur host for Li-S batteries. [Display omitted] [ABSTRACT FROM AUTHOR]

Cost-effective highly efficient and stable catalysts and alkali-resistant anion exchange membranes (AEMs) are critical for practical applications of anion exchange membrane water electrolyzers (AEMWEs). Here, bifunctional non-precious FeCoNiCuMo high entropy alloys (HEAs), electrochemically deposited on nickel mesh as an anode (FeCoNiCuMo/NM) and on carbon paper as a cathode (FeCoNiCuMo/CP), together with a NiFe layered double hydroxide (LDH) loaded AEM (AEM/LDH), were developed for high performance AEMWEs. The AEMWE thus fabricated delivered an ultrahigh current density of 1777 mA cm−2 at 2 V and exhibited remarkable stability with a less than 0.1% cell voltage increase after a 100-hour operation at 100 mA cm−2 at 50 °C, largely outperforming those of the precious metal based AEMWE, composed of IrO 2 /NM as the anode and Pt/C/CP as the cathode, 1231 mA cm−2@2 V and 4.57% increase in cell voltages. Composition of the alkali-resistant, hydrophilic, and water electrolysis active NiFe LDH into the AEM improved not only the electrolyte uptake and operational stability, but also the efficiency of the AEMWE, with a 10% boost in current density achieved at 2 V and a reduction in cell voltage increases from 2.94% to 0.0951%. The present development demonstrates the practicality of AEMWEs toward green hydrogen production. [Display omitted] • Bifunctional non-precious FeCoNiCuMo high entropy alloy catalysts for AEMWE. • Highly alkali-resistant NiFe LDH loaded anion exchange membranes for AEMWE. • Achieve ultrahigh current density of 1777 mA cm−2 at 2 V. • Less than 0.1% cell voltage increase after 100-hour operation at 100 mA cm−2. [ABSTRACT FROM AUTHOR]