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,...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.展开更多
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)^(...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.展开更多
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...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.展开更多
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 c...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.展开更多
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 d...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.展开更多
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 at...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).展开更多
基金supported by the Russian Science Foundation as part of joint project of RSF-NSFC no.21-43-00006“Polysulfide IonSolvent Complexes and Their Electrochemical Behavior in Lithium-Sulfur Batteries”with the National Natural Science Foundation of China(22061132002)。
文摘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.
基金financially supported by the National Natural Science Foundation of China,China(21975251)。
文摘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.
基金supported by the National Natural Science Foundation of China(21972049)the Guangdong Program for Distinguished Young Scholar(2017B030306013)the Science and Technology Planning Project of Guangdong Province(2017B090901020)。
文摘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.
文摘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.
文摘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.
基金financially supported by National Key Research and Development Program of China(2017YFB0307600)Liaoning Revitalization Talents Program(XLYC1802073)Dalian High-level Talent Innovation Support Program(2019RD08)。
文摘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).
