NdF3-LiF melts are commonly used in the electrolysis process of metallic neodymium production. Research on the density and ionic structure of the electrolyte is important for its close connection with the electrolysis...NdF3-LiF melts are commonly used in the electrolysis process of metallic neodymium production. Research on the density and ionic structure of the electrolyte is important for its close connection with the electrolysis mechanism and process. In this paper, the density of LiF-NdF3 melts was studied by the Archimedes method. The results showed that the density decreased with increasing temperature and LiF contents. The changing law was discussed and explained in terms of the micro ionic structure of the melts....展开更多
The system of LiH-LiF-P_2O_5 ionic conductor glass is prepared in neutral atmosphere and glass -forming region is given. The structure and coor- dination of glass are analyzed by IR spectra. Raman spectra and RDF(r). ...The system of LiH-LiF-P_2O_5 ionic conductor glass is prepared in neutral atmosphere and glass -forming region is given. The structure and coor- dination of glass are analyzed by IR spectra. Raman spectra and RDF(r). The result indicates that the (PO_4), (PO_3F) and (LiF_4) tetrahedra are basical structure units of glass network and the coordina- tion number of Li is 4. The coordination number of P is 4. The glass random network structure model is given. The study on structure shows that Li^+, H^- and partial F^- are charge carriers in glass system.展开更多
The structure of a room temperature asymmetrical dicationic ionic liquid （ADIL）, 1-（pyridinium-l-yl） propane- （1-methylpiperidinium） bi[bis（tfifluoromethanesulfonyl）imide] （[PyC3Pi][NTf2]2）, was studied by t...The structure of a room temperature asymmetrical dicationic ionic liquid （ADIL）, 1-（pyridinium-l-yl） propane- （1-methylpiperidinium） bi[bis（tfifluoromethanesulfonyl）imide] （[PyC3Pi][NTf2]2）, was studied by the X-ray difo fraction method. Meanwhile, thermal analysis of [PyC3Pi][NTf2]2 was also studied using non-isothermal thermo- gravimetric analysis （TGA）. The title crystal belongs to the triclinic with space group Pi and unit-cell parameters a ： 0.95217 （8） nm, b = 1.05129 （11 ） nm, c = 1.70523 （14） nm, ct = 89,759 （8）°,β = 80.657 （7）°, γ=68.007 （9）°, and F（000） = 792. Thermal stability and thermal decomposition kinetics of the title compound were also investigated using TGA under the atmosphere of highly pure nitrogen. Heating curves at different rates were cor- related with kinetic equations Friedman and ASTM （also called iso-conversion method）. The values of average activation E （kJ·mol^-1 ） and pre-exponential constant lgA are 149.58 kJ. mol- 1 and 8.83, respectively, which were obtained by the two methods. The kinetic model function, activation energy and pre-exponential constant of this reaction using the multivariate non-linear-regression method were f（a） = （1 -a）（1 ＋ 4.1870a）, 151.04 kJ·mol^-1 and 8.81, respectively, which were basically consistent with iso-conversion methods.展开更多
Molecular dynamics simulation was utilized to investigate the transport and adsorption of chloride in the nanopore of calcium aluminosilicate hydrate(C-A-S-H)with associated cation types of Ca,Mg,Na and K.The local io...Molecular dynamics simulation was utilized to investigate the transport and adsorption of chloride in the nanopore of calcium aluminosilicate hydrate(C-A-S-H)with associated cation types of Ca,Mg,Na and K.The local ionic structure,atomic dynamics and bond stability were analyzed to elucidate the interaction between cations and chloride ions.The results show that interfacial chloride is absorbed through the ion pairing formation in the vicinity of C-A-S-H substrate.Interfacial cations can simultaneously interact aluminosilicate chains,water molecules and Cl^(-)ions,which restrict the motion of interfacial Cl^(-)ions.Pore solution chloride can be immobilized through the solvation effect of cations.Cations along with their hydration shell can connect to neighboring Cl^(-)ions to decrease their mobility.Owing to the varied ionic chemistry,cations show different interaction strength with neighboring water molecules and anions,which determines the chloride transport behavior in the nanopore of C-A-S-H.The chloride immobilization capacity of C-A-S-H nanopore with different associated cations is listed in following order:Mg^(2+)Ca^(2+)<Na^(+)≈K^(+),which agrees reasonably with previous experiments.展开更多
The knowledge on the ionic structure of YCl_(3)-KCl molten system is of guiding significance for the practical production of yttrium metals and yttrium alloys via molten salt electrolysis using this system as electrol...The knowledge on the ionic structure of YCl_(3)-KCl molten system is of guiding significance for the practical production of yttrium metals and yttrium alloys via molten salt electrolysis using this system as electrolyte.In this paper,the theoretical Raman spectra of the ionic groups which may exist in YCl_(3)-KCl molten system are simulated by quantum chemical calculation using Gaussian09 and Gauss View 5.0 programs based on density functional theory(DFT).Then the ionic structures of 20 mol%-60 mol%YCl_(3)-KCl molten salt systems are studied by comparing the Raman shift values of the bands in the theoretical Raman spectra of different ionic groups with the experimental spectra of this system.YCl_(6)^(3-),Y_(2)Cl_(7)^(-),Y_(2)Cl_(8)^(2-)and Y_(2)Cl_(9)^(3-)are thought to exist in the molten system.With the increase of temperature,the relative content of YCl_(6)^(3-)ionic groups increases while those of Y_(2)Cl_(7)^(-),Y_(2)Cl_(8)^(2-)and Y_(2)Cl_(9)^(3-)ionic groups decrease.Moreover,the"lifetime"of all ionic groups decreases within the temperature range of 692-730℃.Meanwhile,the relative contents of Y_(2)Cl_(7)^(-),Y_(2)Cl_(8)^(2-)and Y_(2)Cl_(9)^(3-)increase with the increase of YCl_(3)content,while that of YCl_(6)^(3-)decreases.The wave function analysis of the four ionic groups(YCl_(6)^(3-),Y_(2)Cl_(7)^(-),Y_(2)Cl_(8)^(2-),and Y_(2)Cl_(9)^(3-))is carried out by Multiwfn program.The net charge in each group,the direction of electron migration during the formation of each group,the sites where electrophilic and nucleophilic reactions are most likely to occur in each ionic group,and the order of bond breaking during chemical reactions for the four groups are obtained.展开更多
We report the fabrication of mesoporous tubular graphene（MTG） by a chemical vapor deposition method using Mg O@Zn O core-shell structure as the template. The unique bi-directional ions transfer in unstack graphene l...We report the fabrication of mesoporous tubular graphene（MTG） by a chemical vapor deposition method using Mg O@Zn O core-shell structure as the template. The unique bi-directional ions transfer in unstack graphene layers and high mesopore ratio of MTGs allows capacitance reach 15 μF/cm^2 at 0.5 A/g, and11 μF/cm^2 at 10 A/g, which is closer to theoretical value（21μF/cm^2） than SWCNTs and DWCNTs at either low or high rate. Meanwhile, MTGs exhibited good structural stability, high surface area（701 m^2/g）, high conductivity（30 S/cm） and low oxygen ratio（0.7 atom%）, allowing excellent SC performance. The 4 V EDLC using MTGs and EMIMBF_4 electrolyte exhibited high energy density in wide range of high power density and excellent cycling stability, showing strong potential in EDLC and other electrochemical energy storage systems, in addition, showing significant factor of ion transfer distance for high performance SCs especially operating at high voltage using ionic liquid electrolyte.展开更多
基金Project supported by the National Basic Research Program of China (2007CB210305) the Fundamental Research Funds for the Central Universities (N090302009)
文摘NdF3-LiF melts are commonly used in the electrolysis process of metallic neodymium production. Research on the density and ionic structure of the electrolyte is important for its close connection with the electrolysis mechanism and process. In this paper, the density of LiF-NdF3 melts was studied by the Archimedes method. The results showed that the density decreased with increasing temperature and LiF contents. The changing law was discussed and explained in terms of the micro ionic structure of the melts....
文摘The system of LiH-LiF-P_2O_5 ionic conductor glass is prepared in neutral atmosphere and glass -forming region is given. The structure and coor- dination of glass are analyzed by IR spectra. Raman spectra and RDF(r). The result indicates that the (PO_4), (PO_3F) and (LiF_4) tetrahedra are basical structure units of glass network and the coordina- tion number of Li is 4. The coordination number of P is 4. The glass random network structure model is given. The study on structure shows that Li^+, H^- and partial F^- are charge carriers in glass system.
基金the National Natural Science Foundation of China(21176228)the National Key Technology Support Program of China(2013BAC01B04)the Science and Technology Research Projects of Zhengzhou City(141PQYJS555)
文摘The structure of a room temperature asymmetrical dicationic ionic liquid （ADIL）, 1-（pyridinium-l-yl） propane- （1-methylpiperidinium） bi[bis（tfifluoromethanesulfonyl）imide] （[PyC3Pi][NTf2]2）, was studied by the X-ray difo fraction method. Meanwhile, thermal analysis of [PyC3Pi][NTf2]2 was also studied using non-isothermal thermo- gravimetric analysis （TGA）. The title crystal belongs to the triclinic with space group Pi and unit-cell parameters a ： 0.95217 （8） nm, b = 1.05129 （11 ） nm, c = 1.70523 （14） nm, ct = 89,759 （8）°,β = 80.657 （7）°, γ=68.007 （9）°, and F（000） = 792. Thermal stability and thermal decomposition kinetics of the title compound were also investigated using TGA under the atmosphere of highly pure nitrogen. Heating curves at different rates were cor- related with kinetic equations Friedman and ASTM （also called iso-conversion method）. The values of average activation E （kJ·mol^-1 ） and pre-exponential constant lgA are 149.58 kJ. mol- 1 and 8.83, respectively, which were obtained by the two methods. The kinetic model function, activation energy and pre-exponential constant of this reaction using the multivariate non-linear-regression method were f（a） = （1 -a）（1 ＋ 4.1870a）, 151.04 kJ·mol^-1 and 8.81, respectively, which were basically consistent with iso-conversion methods.
基金Funded by the National Natural Science Foundation of China(Nos.52008002,U21A20149,U2006224 and 51978352)the Open Foundation of the State Key Laboratory of Silicate Materials for Architectures(Wuhan University of Technology)(No.SYSJJ2022-22)Anhui Province Engineering Laboratory of Advanced Building Materials(No.JZCL2202ZR)。
文摘Molecular dynamics simulation was utilized to investigate the transport and adsorption of chloride in the nanopore of calcium aluminosilicate hydrate(C-A-S-H)with associated cation types of Ca,Mg,Na and K.The local ionic structure,atomic dynamics and bond stability were analyzed to elucidate the interaction between cations and chloride ions.The results show that interfacial chloride is absorbed through the ion pairing formation in the vicinity of C-A-S-H substrate.Interfacial cations can simultaneously interact aluminosilicate chains,water molecules and Cl^(-)ions,which restrict the motion of interfacial Cl^(-)ions.Pore solution chloride can be immobilized through the solvation effect of cations.Cations along with their hydration shell can connect to neighboring Cl^(-)ions to decrease their mobility.Owing to the varied ionic chemistry,cations show different interaction strength with neighboring water molecules and anions,which determines the chloride transport behavior in the nanopore of C-A-S-H.The chloride immobilization capacity of C-A-S-H nanopore with different associated cations is listed in following order:Mg^(2+)Ca^(2+)<Na^(+)≈K^(+),which agrees reasonably with previous experiments.
基金financially supported by the National Natural Science Foundation of China (No.51974081)the Fundamental Research Funds for the Central Universities (No.N2225045)MOE of China and WEIQIAO Industry-Education Cooperation Project (No.2021021800102)。
文摘The knowledge on the ionic structure of YCl_(3)-KCl molten system is of guiding significance for the practical production of yttrium metals and yttrium alloys via molten salt electrolysis using this system as electrolyte.In this paper,the theoretical Raman spectra of the ionic groups which may exist in YCl_(3)-KCl molten system are simulated by quantum chemical calculation using Gaussian09 and Gauss View 5.0 programs based on density functional theory(DFT).Then the ionic structures of 20 mol%-60 mol%YCl_(3)-KCl molten salt systems are studied by comparing the Raman shift values of the bands in the theoretical Raman spectra of different ionic groups with the experimental spectra of this system.YCl_(6)^(3-),Y_(2)Cl_(7)^(-),Y_(2)Cl_(8)^(2-)and Y_(2)Cl_(9)^(3-)are thought to exist in the molten system.With the increase of temperature,the relative content of YCl_(6)^(3-)ionic groups increases while those of Y_(2)Cl_(7)^(-),Y_(2)Cl_(8)^(2-)and Y_(2)Cl_(9)^(3-)ionic groups decrease.Moreover,the"lifetime"of all ionic groups decreases within the temperature range of 692-730℃.Meanwhile,the relative contents of Y_(2)Cl_(7)^(-),Y_(2)Cl_(8)^(2-)and Y_(2)Cl_(9)^(3-)increase with the increase of YCl_(3)content,while that of YCl_(6)^(3-)decreases.The wave function analysis of the four ionic groups(YCl_(6)^(3-),Y_(2)Cl_(7)^(-),Y_(2)Cl_(8)^(2-),and Y_(2)Cl_(9)^(3-))is carried out by Multiwfn program.The net charge in each group,the direction of electron migration during the formation of each group,the sites where electrophilic and nucleophilic reactions are most likely to occur in each ionic group,and the order of bond breaking during chemical reactions for the four groups are obtained.
基金financial support of National Key R&D Program of China (No. 2016YFA0200102)Beijing Municipal Science and Technology Project (No. Z161100002116012)
文摘We report the fabrication of mesoporous tubular graphene（MTG） by a chemical vapor deposition method using Mg O@Zn O core-shell structure as the template. The unique bi-directional ions transfer in unstack graphene layers and high mesopore ratio of MTGs allows capacitance reach 15 μF/cm^2 at 0.5 A/g, and11 μF/cm^2 at 10 A/g, which is closer to theoretical value（21μF/cm^2） than SWCNTs and DWCNTs at either low or high rate. Meanwhile, MTGs exhibited good structural stability, high surface area（701 m^2/g）, high conductivity（30 S/cm） and low oxygen ratio（0.7 atom%）, allowing excellent SC performance. The 4 V EDLC using MTGs and EMIMBF_4 electrolyte exhibited high energy density in wide range of high power density and excellent cycling stability, showing strong potential in EDLC and other electrochemical energy storage systems, in addition, showing significant factor of ion transfer distance for high performance SCs especially operating at high voltage using ionic liquid electrolyte.
