Effect of the anionic composition of sulfolane based electrolytes on the performances of lithium-sulfur batteries

In lithium-sulfur batteries,cell design,specifically electrolyte design,has a key impact on the battery performance.The effect of lithium salt anion donor number(DN)(DN[PF_(6)]^(-)=2.5,DN[N(SO_(2)CF_(3))_(2)]^(-)=5.4,DN[ClO_(4)]^(-)=8.4,DN[SO_(3)CF_(3)]^(-)=16.9,and DN[NO_(3)]^(-)=21.1)on the patterns of lithium-sulfur batteries and lithium metal electrode performances with sulfola ne-based electrolytes is investigated.An increase in DN of lithium salt anions leads to an increase in the depth and rate of electrochemical reduction of sulfur and long-chain lithium polysulfides and to a decrease in those for medium-and short-chain lithium polysulfides.DN of lithium salt anions has weak effect on the discharge capacity of lithium-sulfur batteries and the Coulomb efficiency during cycling,with the exception of LiSO_(3)CF_(3)and LiNO_(3).An increase in DN of lithium salt anions leads to an increase in the cycling duration of lithium metal anodes and to a decrease in the presence of lithium polysulfides.In sulfolane solutions of LiNO_(3)and LiSO_(3)CF_(3),lithium polysulfides do not affect the cycling duration of lithium metal anodes.

Hierarchical intercalation of tetrafluoroborate anion into graphite electrode from sulfolane

The anion storage behavior of graphite positive electrode in a dual-ion battery is closely related to the solvation of anion in the corresponding electrolyte solution.The classical electrolyte solutions of Li BF_(4)^(-)sulfolane(SL)have long been recognized in the community of lithium batteries and still appear promising in dual-ion batteries.Nevertheless,the solvation of BF_(4)^(-)by SL has seldom been addressed before.In this study,the solvation states of SL-BF_(4)^(-)are adjusted by varying LiBF_(4)concentration or introducing auxiliary salts of LiPF_6or SBPBF_(4)(SBP:spiro-(1,1')-bipyrrolidinium)in the electrolyte solutions of Li/graphite dualion cells.The electrochemical storage processes of SL-BF_(4)^(-)anions in graphite electrodes are investigated through in situ X-ray diffraction measurements.Two kinds of graphite intercalation compounds(GICs)with contrastive intercalation gallery heights(IGHs)have been discovered,which are ascribed to the storage of different kinds of SL-BF_(4)^(-)anions in graphite electrode.The interactions between ions and SL in the electrolyte solutions are characterized by Fourier transform infrared spectroscopy and then correlated with the performance of Li/graphite cells.

Sulfolane-Graphite Incompatibility and Its Mitigation in Li-ion Batteries

The non-flammability and high oxidation stability of sulfolane(SL)make it an excellent electrolyte candidate for lithium-ion batteries(LIBs).However,its incompatibility with graphitic anode prevents the realization of these advantages.To understand how this incompatibility arises on molecular level so that it can be suppressed,we combined theoretical calculation and experimental characterization and reveal that the primary Li^(+) solvation sheath in SL is depleted of fluorine source.Upon reduction,SL in such fluorine-poor solvation sheath generates insoluble dimer with poor electronic insulation,hence leading to slow but sustained parasitic reactions.When fluorine content in Li^(+)-SL solvation sheath is increased via salt concentration,a high stability LiF-rich interphase on graphite can be formed.This new understanding of the failure mechanism of graphite in SL-based electrolyte is of great significance in unlocking many possible electrolyte solvent candidates for the high-voltage cathode materials for next-generation LIBs.

Measurement and correlation of liquid-liquid equilibrium for the ternary system(water+1,2-dichloroethane+sulfolane)at 288.15,298.15,and 308.15 K

Sulfolane is an important aprotic polar solvent.Liquid-liquid equilibrium(LLE)data for the ternary systems of water+1,2-dichloroethane+sulfolane were measured at temperatures of 288.15,298.15 and 308.15 K under the atmospheric pressure.The distribution coefficient and selectivity were determined from the measured LLE data,which showed that 1,2-dichloroethane is a suitable extractant for the recovery of sulfolane from its aqueous solution.The nonrandom two-liquid(NRTL)model and the universal quasi-chemical(UNIQUAC)model were utilized to correlate the experimental LLE data.The low values of RMSD indicated that the ternary system could be fitted well by the NRTL and UNIQUAC models.The consistency of the binary interaction parameters for the two thermodynamic models obtained was confirmed by the topological information contained in the Gibbs energy of mixing function(G^(M)/RT).

Excess Molar Volumes and Viscosities of Binary Mixtures of p-Xylene with Cyclohexane, n-Heptane, n-Octane, Sulfolane, N-Methyl-2-pyrrolidone and Acetic Acid at 303.15 K and 323.15 K and Atmospheric Pressure

Experimental data on density and viscosity at 303.15K and 323.15K are presented for the binary mixtures of p-xylene with cyclohexane, n-heptane, n-octane, sulfolane, N-methyl-2-pyrrolidone and acetic acid.From these data, the excess molar volume and deviations in viscosity have been calculated. The computed quantities have been fitted to the Redlich-Kister Equation to derive coefficients and estimate the standard error values. Results are discussed in terms of intermolecular interactions.

Densities, Viscosities and Related Properties for Binary Mixtures of Sulfolane + p-Xylene, Sulfolane + Ethylbenzene in the Temperature Range from 303.15K to 353.15K

Densities and viscosities of the binary systems of sulfolane + ethylbenzene, sulfolane + p-xylene have been experimentally determined in temperature interval 303.15-353.15 K and at atmospheric pressure for the whole composition range. The excess molar volumes and viscosity deviations were computed. The computed quantities have been fitted to Redlich-Kister equation. Excess molar volumes and viscosity deviation show a systematic change with increasing temperature. Two mixtures exhibit negative excess volumes with a minimum which occurs approximately at x = 0.5. The effect of the size, shape and interaction of components on excess molar volumes and viscosity deviations is discussed.

Synthesizing an inorganic-rich solid electrolyte interphase by tailoring solvent chemistry in carbonate electrolyte for enabling high-voltage lithium metal batteries

High-voltage(>4.0 V)lithium metal battery(LBM)is considered to be one of the most promising candidates for next-generation high-energy batteries.However,the commercial carbonate electrolyte delivers a poor compatibility with Li metal anode,and its organic dominated solid electrolyte interphase(SEI)shows a low interfacial energy and a slow Li^(+)diffusion ability.In this work,an inorganic LiF-Li_(3)N rich SEI is designed to enable high-voltage LBM by introducing nano-cubic LiF and LiNO_(3)into1 M LiPF_(6)ethylene carbonate(EC)/dimethyl carbonate(DMC)(v:v=1:1)electrolyte.Specifically,the unique nano-cubic structure of as-synthetized LiF particles achieves its high concentration dissolution in carbonate electrolyte to enhance the interfacial energy of SEI.In addition,tetramethylene sulfolane(TMS)is used as a carrier solvent to dissolve LiNO_(3)in the carbonate electrolyte,thereby deriving a Li_(3)N-rich SEI.As a result,the as-designed electrolyte shows a high average Li plating/striping CE of 98.3%after 100 cycles at 0.5 m A cm^(-2)/0.5 mA h cm^(-2).Furthermore,it also enables the ultrathin Li(~50μm)‖LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM,4.4 mA h cm^(-2))full cell to deliver a high-capacity retention of 80.4%after 100 cycles with an outstanding average CE of 99.7%.Notably,the practical application prospect of the modified electrolyte is also estimated in LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)‖Li pouch cell with an energy density of 261.2 W h kg^(-1).This work sheds light on the internal mechanism of Li^(+)transport within the inorganic dominated SEI and provides a simple approach to stabilize the high-voltage LMBs.

Selection of extractive agent for mixture chlorobenzene and measurement of VLE data for m-dichlorobenzene-p-dichlorobenzene -o-dichlorobenzene -diphenylamine

Extractive agents of extractive distillation separation for mixtures of dichlorobenzene were analyzed and compared, gas-liquid equilibrium data （VLE data） was measured for dichlorobenzene and diphenylamine, the appropriate extractive agent was selected by relatively volatility, the temperature was studied on the effect of extractive separation. VLE data was measured for dichlorobenzene, the parameters were simulated in Wilson equation. The infinite dilute activity coefficient of dichlorobenzene in diphenylamine were measured by chromatogram apparatus, the model parameters were correlated by the single parameter method for dichlorobenzene and diphenyl -amine, VLE data of m-dichlorobenzene-p- dichlorobenzene -o-dichlorobenzene-diphenylamine system was measured and calculated by six part model parameters. The results of correlation and experiment were provided a basis for study of extractive distillation simulation and experiment in this work.

芳烃抽提装置无油污水零排放的优化措施及效果

本文针对Sulfolane工艺的芳烃抽提装置污水排放问题,提出了负压劣质溶剂再生工艺、溶剂比设计操作、电动真空泵设计、系统水内闭循环、蒸汽凝液循环利用等优化措施来解决装置无油污水零排放的技术难题,并对优化后的节资、节能、环保等效果做了简述。

Functionalizing the interfacial double layer to enable uniform zinc deposition

Due to the unsatisfactory electrode/electrolyte interface,the metallic Zn dendrites and corrosion are easily induced,severely hindering the applications of zinc-ion batteries(ZIBs).Herein,a strategy that engineers the interfacial double layer by an extremely low concentration of sulfolane is proposed to tune the Zn stripping/plating behavior.It is revealed that the highly-polar sulfolane can predominately occupy the inner Helmholtz layer over water,and then regulate the upcoming Zn2+to directly deposit downward.Simultaneously,the widened Helmholtz layer can weaken the electric field intensity,which will generate more nucleation sites and reduce the nuclei radius,thereby promoting uniform zinc deposition as well.Moreover,corrosion byproducts can be inhibited since fewer water molecules can contact the Zn electrodes.Consequently,the battery performance can be naturally optimized.With an optimum amount of sulfolane,the Zn||Zn battery can operate for more than 1,100 h under1 m A cm^(-2)and 1 m Ah cm^(-2).And the as-constructed Zn||NaV_(3)O_(8)·1.5H_(2)O battery demonstrates considerably higher cycling stability than that without sulfolane.Overall,this work has provided a deep insight into constructing a functional interfacial double layer to regulate zinc deposition,which can also act as a reference for other metal-based batteries.

Cyano-containing ionic liquids for the extraction of aromatic hydrocarbons from an aromatic/aliphatic mixture

Ionic liquids can replace conventional solvents in aromatic/aliphatic extractions, if they have higher aromatic distribution coef- ficients and higher or similar aromatic/aliphatic selectivities. Also physical properties, such as density and viscosity, must be taken into account if a solvent is applied in an industrial extraction process. Cyano-containing ionic liquids have a lower den- sity than the benchmark solvent sulfolane and a higher viscosity. Sulfolane is from a hydrodynamic point of view a better sol- vent than ionic liquids for the aromatic/aliphatic extraction. The most suitable ionic liquids for the extraction of aromatic hy- drocarbons from a mixture of aromatic and aliphatic hydrocarbons are [bmim]C(CN)3, [3-mebupy]N(CN)2, [3-mebupy]C(CN)3, [3-mebupy]B(CN)4 and [mebupyrr]B(CN)4. They have factors of 1.2-2.3 higher mass-based distribution coefficients than sul- folane and a similar or higher, up to a factor of 1.9 higher, aromatic/aliphatic selectivity than sulfolane. The IL [3-mebupy]N(CN)2 is a better extractant for the separation of toluene from a mixture of toluene/n-heptane in a pilot plant Ro- tating Disc Contactor (RDC) than sulfolane.

Simulation of CO_(2) removal from ethane with Sulfinol-MtAMP solvent instead of DEA solvent in the South Pars phases 9 and 10 gas processing facility

Raw gas gathered from well production has to be treated to extract its ethane,to remove carbon dioxide(CO2)from it and to dry it,so that the send-out ethane gas complies with transport constraints and meets sales-gas specifications.Two distinct families of solvents are used generically for such gas treatment:chemical and physical solvents.The South Pars gas field development phases 9 and 10 feeds gas and natural gas liquids into a processing and fractionation plant(one of the largest gas processing plants in Iran),and is associated with concentrations of 5.37%mole CO2 in the raw gas produced.Furthermore,there are potential problems associated with the CO2 treatment,such as the high-energy requirements for amine solvent regeneration,corrosion caused by aqueous amine solvents and waste/losses(solubility,vaporization)of the solvent used to remove CO2 in the ethane treatment unit.A feasibility simulation study was conducted to evaluate the utilization of Sulfinol-M t AMP solvent(Sulfolane plus Methyl di-ethanol amine plus 2-amino-2-methyl-1-propanol(AMP)plus H2O)to replace the aqueous amine solvent(DEA)currently used in the ethane treatment unit of South Pars phases 9 and 10 gas processing plant.The simulation of the Sulfinol-M t AMP process demonstrates less energy consumption(11241.242 kw versus 11290.398 kw for DEA),negligible corrosion and lower losses of solvent(376.493 kg/h versus 409.2421 kg/h)relative to alternative solvents considered,because of its low vapor pressure.