4 research outputs found

    High Chaos Induced Multiple-Anion-Rich Solvation Structure Enabling Ultrahigh Voltage and Wide Temperature Lithium-Metal Batteries

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    The optimal electrolyte for ultrahigh energy density (>400 Wh/kg) lithium-metal batteries with a LiNi0.8Co0.1Mn0.1O2 cathode is required to withstand high voltage (≥4.7 V) and be adaptable over a wide temperature range. However, the battery performance is degraded by aggressive electrode–electrolyte reactions at high temperature and high voltage, while excessive growth of lithium dendrites usually occurs due to poor kinetics at low temperature. Accordingly, the development of electrolytes has encountered challenges in that there is almost no electrolyte simultaneously meeting the above requirements. Herein, a high chaos electrolyte design strategy is proposed, which promotes the formation of weak solvation structures involving multiple anions. By tailoring a Li+-EMC-DMC-DFOB–-PO2F2–-PF6– multiple-anion-rich solvation sheath, a robust inorganic-rich interphase is obtained for the electrode–electrolyte interphase (EEI), which is resistant to the intense interfacial reactions at high voltage (4.7 V) and high temperature (45 °C). In addition, the Li+ solvation is weakened by the multiple-anion solvation structure, which is a benefit to Li+ desolventization at low temperature (−30 °C), greatly improving the charge transfer kinetics and inhibiting the lithium dendrite growth. This work provides an innovative strategy to manipulate the high chaos electrolyte to further optimize solvation chemistry for high voltage and wide temperature applications

    Transition-Metal-Free Cleavage of C–C Triple Bonds in Aromatic Alkynes with S<sub>8</sub> and Amides Leading to Aryl Thioamides

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    A novel transition-metal-free cleavage reaction of C–C triple bonds in aromatic alkynes with S<sub>8</sub> and amides furnishes aryl thioamides in moderate to excellent yields. The remarkable features of this thioamidation include the metal-free cleavage of C–C triple bond, mild reaction conditions, as well as wide substrate scope that is particularly compatible with some internal aromatic alkynes and acetamides

    Entropy-Driven Enhancement of the Conductivity and Phase Purity of Na<sub>4</sub>Fe<sub>3</sub>(PO<sub>4</sub>)<sub>2</sub>P<sub>2</sub>O<sub>7</sub> as the Superior Cathode in Sodium-Ion Batteries

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    Na4Fe3(PO4)2(P2O7) (NFPP) is regarded as a promising cathode material for sodium-ion batteries (SIBs) owing to its low cost, easy manufacture, environmental purity, high structural stability, unique three-dimensional Na-ion diffusion channels, and appropriate working voltage. However, for NFPP, the low conductivity of electrons and ions limits their capacity and power density. The generation of NaFeP2O7 and NaFePO4 inhibits the diffusion of sodium ions and reduces reversible capacity and rate performance during the manufacturing process in synthesis methods. Herein, we report an entropy-driven approach to enhance the electronic conductivity and, concurrently, phase purity of NFPP as the superior cathode in sodium-ion batteries. This approach was realized via Ti ions substituting different ratios of Fe-occupied sites in the NFPP lattice (denoted as NTFPP-X, T is the Ti in the lattice, X is the ratio of Ti-substitution) with the configurational entropic increment of the lattice structures from 0.68 R to 0.79 R. Specifically, 5% Ti-substituted lattice (NTFPP-0.05) inducing entropic augmentation not only improves the electronic conductivity from 7.1 × 10–2 S/m to 8.6 × 10–2 S/m but also generates the pure-phase of NFPP (suppressing the impure phases of the NaFeP2O7 and NaFePO4) of the lattice structure, which is validated by a series of characterizations, including powder X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT). Benefiting from the Ti replacement in the lattice, the optimal NTFPP-0.05 composite shows a high first discharge capacity (118.5 mAh g–1 at 0.1 C), superior rate performance (70.5 mAh g–1 at 10 C), and excellent long cycling life (1200 cycles at 10 C with capacity retention of 86.9%). This research proposes a new entropy-driven approach to improve the electrochemical performance of NFPP and reports a low-cost, ultrastable, and high-rate cathode material of NTFPP-0.05 for SIBs

    <i>o</i>‑Semiquinone Radical and <i>o</i>‑Benzoquinone Selectively Degrade Aniline Contaminants in the Periodate-Mediated Advanced Oxidation Process

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    Advanced oxidation processes (AOPs) often employ strong oxidizing inorganic radicals (e.g., hydroxyl and sulfate radicals) to oxidize contaminants in water treatment. However, the water matrix could scavenge the strong oxidizing radicals, significantly deteriorating the treatment efficiency. Here, we report a periodate/catechol process in which reactive quinone species (RQS) including the o-semiquinone radical (o-SQ•–) and o-benzoquinone (o-Q) were dominant to effectively degrade anilines within 60 s. The second-order reaction rate constants of o-SQ•– and o-Q with aniline were determined to be 1.0 × 108 and 4.0 × 103 M–1 s–1, respectively, at pH 7.0, which accounted for 21% and 79% of the degradation of aniline with a periodate-to-catechol molar ratio of 1:1. The major byproducts were generated via addition or polymerization. The RQS-based process exhibited excellent anti-interference performance in the degradation of aniline-containing contaminants in real water samples in the presence of diverse inorganic ions and organics. Subsequently, we extended the RQS-based process by employing tea extract and dissolved organic matter as catechol replacements as well as metal ions [e.g., Fe(III) or Cu(II)] as periodate replacements, which also exhibited good performance in aniline degradation. This study provides a novel strategy to develop RQS-based AOPs for the highly selective degradation of aniline-containing emerging contaminants
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