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Severe Zn dendrite growth and side reactions greatly limit the application of aqueous zinc-ion batteries. Herein, we design a layer of polyionic liquid (PCAVImBr) film with a tunable pore size and charge density on the Zn anode to endow homogenized distribution of an electronic field, acerated Zn 2+ permeation, and inhabitation of water entry. Such an optimal combination is achieved via a polymerization induced phase separation strategy, where the enhanced cross-linking density arrests the phase separation in a shallow depth and vice versa. Furthermore, the Zn@PCAVImBr electrode has good plating/stripping reversibility, which retains a 99.6% CE efficiency after 3000 cycles. The symmetric cells can achieve a cycle life of more than 2400 h at different current densities. It is worth mentioning that the NVO//Zn@PCAVImBr full cell can still reach a 91.2% capacity retention after nearly 4000 cycles at a high current of 10 A g -1 , and provides new insights for the future research of zinc-ion battery anodes.

We used atomistic simulations and compared the prediction of three different implementations of force fields, namely, the original full partial charge system, the scaled partial charge system, and the Drude oscillator polarizable force field and its effect on the structural and dynamic properties of a polymeric ionic liquid, poly(1-butyl-3-methyl-imidazolium hexafluorophosphate). We found that both the scaled and the polarizable force field models yield comparable predictions of structural and dynamic properties, although the scaled charge model artificially lowers the first-neighbor peak of the radial distribution function and therefore leads to a slight reduction in density. The full charge model was not accurate in its prediction of the dynamic properties but could reproduce the structural properties. With a refined analysis method for the ion-hopping mechanisms, we found that all three methods produce very similar conclusions, namely, that the mobile anion is associated with three cations from two distinct polymer chains and that the fractions of inter- and intramolecular hopping events are comparable. Our results demonstrate that the scaled charge force fields provide a computationally efficient means to capture polarizability effects on both the structural and dynamic properties of polymeric ionic liquid systems.

Due to high volatility and water solubility, 2,4-dichlorophenoxyacetic acid (2,4-D) can easily enter into the atmosphere and water bodies by volatilization, drift, leaching, or runoff, which results in potential threats to the environment and human health. The physicochemical properties of pesticides can be regulated by preparing their ionic liquids. In this work, a series of dicationic ionic liquids (DILs) of 2,4-D were prepared to reduce its environmental risk and enhance herbicidal activity. The solubility, octanol-water partition coefficient, surface tension, and volatilization rate results of DILs showed that these properties could be optimized by choosing appropriate countercations. Compared to 2,4-D ammonium salt, DILs have lower volatility, water solubility, and surface tension as well as higher lipophilicity. Benefiting from optimized physicochemical properties, DILs HIL8-12 exhibited better herbicidal activity against three typical broadleaf weeds than 2,4-D ammonium salt, and their fresh weight inhibition rates increased by 2.74-46.84%. The safety assessment experiment indicated that DILs were safer to wheat than commercialized forms of 2,4-D. The DILs could reduce the environmental risk of 2,4-D caused by high volatility and water solubility and would be potential alternatives to its commercialized formulations.

Innovative valorization of naturally abundant and renewable lignocellulosic biomass is of great importance in the pursuit of a sustainable future and biobased economy. Ionic liquids (ILs) as an important kind of green solvents and functional fluids have attracted significant attention for the catalytic transformation of lignocellulosic feedstocks into a diverse range of products. Taking advantage of some unique properties of ILs with different functions, the catalytic transformation processes can be carried out more efficiently and potentially with lower environmental impacts. Also, a new product portfolio may be derived from catalytic systems with ILs as media. This review focuses on the catalytic chemical conversion of lignocellulose and its primary ingredients (i.e., cellulose, hemicellulose, and lignin) into value-added chemicals and fuel products using ILs as the reaction media. An outlook is provided at the end of this review to highlight the challenges and opportunities associated with this interesting and important area.

The development of meaningful ways to transfer biomass into useful materials, more efficient energy carriers, and/or carbon storage deposits is a profound challenge of our days. Herein, an ionothermal carbonization (ITC) method, via treating natural resources (glucose, cellulose, and sugar cane bagesse) in nonmetal ionic liquids (ILs) at ∼200 °C, is established for the fabrication of porous heteroatom-doped carbon materials with high yield. Commercial ILs with bulky bis(trifluoromethylsulfonyl)imide anion or cross-linkable nitrile group were found to be efficient and recyclable templates for porosity control, leading to exciting nanoarchitectures with promising performance in oxygen reduction reaction. The optimized ILs (12 mL) can dissolve and directly convert up to 15 g of glucose into porous carbon materials (SBET: 272 m(2)/g) one time. This ITC method relies on the synergistic use of structure-directing effect, good biomass solubility, and excellent thermal stability of ILs, and provides a sustainable strategy for exploiting biomass.

The basicity of ionic liquids (ILs) underlies many important IL-based processes including the dissolution and conversion of cellulose, the capture of CO2, and metal catalysis. In this work, we have disclosed the nature of the basicity of ILs, i.e., the difference between the basicity of IL and the basicity of the molecular solvent and inorganic salt, through a quantitative electrostatic and electronic analysis of the molecular surface for the first time. The results reveal one of the distinctive properties of ILs (enhanced basicity over molecular solvents and inorganic salts with the same basic site) stemming from their special electrostatic environment and microstructure. The enhancement is significant, from either the electrostatic aspect or the covalent aspect of basicity. The peculiar electrostatic environment of ILs leads to stronger basicity than similar molecular solvents, and the relatively freer microstructure of ILs contributes to the enhancement of basicity over their inorganic analogues. These results are highly instructive for better understanding the unique value of ILs and designing novel ILs to improve the efficiency of basicity-related processes.

In order to expand our understanding of a potential zinc-basedbattery electrolyte, we have characterized the physical and transportproperties of the ionic liquid (IL) 1-butyl-1-methylpyrrolidiniumdicyanamide ([C4mpyr][dca]) containing various levels ofboth Zn2+and H2O. Detailed measurements ofdensity, viscosity, conductivity, and individual anion and cationdiffusion coefficients using pulsed-field-gradient (PFG) NMR combinedwith NMR chemical shifts and spin–lattice relaxation (T1) NMR experiments provide insights into themotion and chemical environment of all molecular species. We findthat the various techniques for probing ion transport and dynamicsform a coherent picture as a function of electrolyte composition.Zn2+addition causes a moderate reduction in the self-diffusionof the IL anion and cation, whereas the addition of H2Oincreases ion mobility by increasing the liquid’s overall fluidity.Temperature-dependent 13C T1experiments of the dca carbon analyzed using Bloembergen–Purcell–Poundfits show monotonic slowing of anion dynamics with Zn2+addition, suggesting increased Zn2+/dca–association. T1experiments show minimalchange in the spin–lattice relaxation of cation or anion uponH2O addition, suggesting that H2O is playingno significant role in Zn2+speciation. Finally, we employa novel electrophoretic NMR technique to directly determine the electrophoreticmobility of the C4mpyr cation, which we discuss in thecontext of impedance-based conductivity measurements. [ABSTRACT FROM AUTHOR]

High methane dissolution capacity in a liquid is important for methane storage and transformation. In this work, methane solubility in different ionic liquids (ILs) was studied and was found associated with IL's structural and physical properties. In imidazolium-based ILs, ILs containing C-F and long alkyl chain showed high methane solubility mainly due to lower surface tension and molar density. Reducing the surface tension of solvent by adding 0.16 mol of trimethyl-1-propanaminium iodide (FC-134) with respect to [Bmim][NTf2] increased methane solubility by 39.3%. In situ high-pressure attenuated total reflection Fourier transform infrared spectroscopic results indicated a reversible process of methane dissolution in the ILs. The antisymmetric C-H stretching band of dissolved methane in ILs showed highly prominent rotational-vibrational bands with high intensity and narrow half-peak width compared to gaseous methane. Induced interaction between methane and IL resulted in increased dipole variation strength and reduced methane molecular symmetry. The constant antisymmetric C-H stretching peak at 3016.85 cm-1 revealed an unconstrained methane rotation in the stable physical and chemical environment of IL. Methane insertion into the IL's intranetwork space needs activation energy to overcome the interaction of cation-anion network. Kinetic analysis of methane in [Bmim][NTf2] and [Bmim][HSO4] at different temperatures indicated that methane dissolution in these two ILs was a reversible first-order and very weak endothermic process and that methane dissolution required high activation energy in ILs with stronger cation-anion interaction. [ABSTRACT FROM AUTHOR]

Ionic liquids have been widely studied as effective reaction media for the conversion of glucose or cellulose to 5-hydroxymethhylfurfural (5-HMF). However, the recovery of 5-HMF from ionic liquids, typically carried out by extraction, has been encountered with very low extraction efficiency, which limited the reusability of the solvents. Through this work, based on the model biphasic system that consists of 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) as the ionic liquid phase and methyl isobutyl ketone (MIBK) as the extractant phase, the dominant force that suppresses the extraction efficiency of 5-HMF was identified as being the strong hydrogen bonding between 5-HMF and [BMIM]Cl. Solvent mediation with functional promoters have been established as a new strategy to shift this force, resulting in improved extraction efficiency of 5-HMF from the ionic liquid. For example, with ethanol as a promoter, the distribution coefficient of 5-HMF was about 10 times higher than that without a promoter. [ABSTRACT FROM AUTHOR]