Engineering optimization approach of nonaqueous electrolyte for sodium ion battery with long cycle life and safety

Electrolyte design strategies are closely related to the capacities, cycle life and safety of sodium–ion batteries. In this study, we aimed to optimize electrolyte with the focus on engineering aspects. The basic physicochemical properties including ionic conductivity, viscosity,wettability and thermochemical stability of the electrolytes using Na PF6 as the solute and the mixed solvent with different components of EMC,DMC or DEC in PC or EC were systematically measured. Ah pouch cell with NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)/hard carbon electrodes was used to evaluate the performance of the prepared electrolytes. By using the Inductive Coupled Plasma Emission Spectrometer(ICP), X-ray photoelectron spectroscopy(XPS), Thermogravimetric-differential scanning calorimetry(TG-DSC) and Accelerating Rate Calorimeter(ARC), we show that an optimized electrolyte can effectively promote the formation of a protective interfacial layer on two electrodes, which not only retards parasitic reactions between the electrodes and electrolyte but also suppresses dissolution of metal ions from the cathode. With an optimized electrolyte, a NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)/hard carbon cell can attain 56.16% capacity retention under the low temperature of -40℃, and can be able to retain 80%capacity retention after more than 2500 cycles while presenting excellent thermal safety.

The application of carbon materials in nonaqueous Na‐O2 batteries

Na‐O2 batteries are advantageous as the candidates of next‐generation electric vehicles due to their ultrahigh theoretical energy density and have attracted enormous attention recently.Tremendous efforts have been devoted to improve the Na‐O2 battery performance by designing advanced electrodes with various carbonbased materials.Carbon materials used in Na‐O2 batteries not only function as the air electrode to provide active sites and accommodate discharge products but also as Na anode protectors against dendrite growth and chemical/electrochemical corrosion.In this review,we mainly focus on the application of various carbonbased materials in Na‐O2 batteries and highlight their advances.The scientific understanding on the fundamental design of the material microstructure and chemistry in relation to the battery performance are summarized.Finally,perspectives on enhancing the overall battery performance based on the optimization and rational design of carbon‐based cell components are also briefly anticipated.

Replacement of annular domain with trapezoidal domain in computational modeling of nonaqueous-phase-liquid dissolution-front propagation problems

In order to simulate the instability phenomenon of a nonaqueous phase liquid(NAPL) dissolution front in a computational model, the intrinsic characteristic length is commonly used to determine the length scale at which the instability of the NAPL dissolution front can be initiated. This will require a huge number of finite elements if a whole NAPL dissolution system is simulated in the computational model. Even though modern supercomputers might be used to tackle this kind of NAPL dissolution problem, it can become prohibitive for commonly-used personal computers to do so. The main purpose of this work is to investigate whether or not the whole NAPL dissolution system of an annular domain can be replaced by a trapezoidal domain, so as to greatly reduce the requirements for computer efforts. The related simulation results have demonstrated that when the NAPL dissolution system under consideration is in a subcritical state, if the dissolution pattern around the entrance of an annulus domain is of interest, then a trapezoidal domain cannot be used to replace an annular domain in the computational simulation of the NAPL dissolution system.However, if the dissolution pattern away from the vicinity of the entrance of an annulus domain is of interest, then a trapezoidal domain can be used to replace an annular domain in the computational simulation of the NAPL dissolution system. When the NAPL dissolution system under consideration is in a supercritical state, a trapezoidal domain cannot be used to replace an annular domain in the computational simulation of the NAPL dissolution system.

Comparison of capacitive behavior of activated carbons with different pore structures in aqueous and nonaqueous systems

The pore structures of two activated carbons from sawdust with KOH activation and coconut-shell with steam activation for supercapacitor were analyzed by N2 adsorption method. The electrochemical properties of both activated carbons in 6 mol/L KOH solution and 1 mol/L EtgNPF4/PC were compared, and the effect of pore structure on the capacitance was investigated by cyclic voltammetry, AC impedance and charge-discharge measurements. The results indicate that the capacitance mainly depends on effective surface area, but the power property mainly depends on mesoporosity. At low specific current （1 A/g）, the maximum specific Capacitances of 276.3 F/g in aqueous system and 123.9 F/g in nonaqueous system can be obtained from sawdust activated carbon with a larger surface area of 1 808 m^2/g, butat a high specific current, the specific capacitance of coconut-shell activated carbon with a higher mesoporosity of 75.1% is more excellent. Activated carbon by KOH activation is fitter for aqueous system and that by steam activation is fitter for nonaqueous system.

Solubility of CO_(2) in nonaqueous system of 2-(butylamino)ethanol with 2-butoxyethanol:Experimental data and model representation

Nonaqueous amine-based system is an attractive solution to overcome high-energy-intensive CO_(2) capture process using the conventional aqueous amines.Advanced nonaqueous absorbent of 2-(butylamino)ethanol(BAE)with 2-butoxyethanol(2-BE)has been recently proposed for low-energyconsumption CO_(2) capture.In this work,Henry’s law constants of CO_(2) in the BAE/2-BE blend were obtained by N_(2)O/CO_(2) analogy,and correlated in the temperature range of(283–333)K.Vapor-liquid equilibrium(VLE)data for the BAE+CO_(2)+2-BE system at 65.4%(mass)BAE were also determined in a stirred equilibrium cell at temperatures of(313–393)K and CO_(2) partial pressures up to 275 kPa.A single apparent equilibrium constant KCO_(2);app was proposed for this system and correlated as a function of temperature,carbonated degree of amine and CO_(2) loading.Solubility data were well represented by the modified Kent-Eisenberg model with an average absolute relative deviation(AARD)of 13%.

NONAQUEOUS SERS:IMIDAZOLE IN METHANOL SOLUTION AT A SILVER ELECTRODE

This paper emphasizes the observation of SERS spectra of imidazole /LiCl in methanol solution at a silver electrode and a qualitative explaina- tion of the relationship between HERS spectra and molecular vibrational modes, and the relationship between SERS spectrum in aqueous and that in nonaqueous system.

Simultaneous determination of berberine,matrine and oxymatrine in traditional Chinese medicines by using nonaqueous capillary electrophoresis

A rapid method for the simultaneous determination of berberine(BBR),matrine(MT)and oxymatrine(OMT)by nonaqueous capillary electrophoresis(NACE)was developed.Optimum separation of the analytes was obtained on a 50cm×50μm i.d.fused-silica capillary using a non-aqueous buffer system of 70mM ammonium acetate,7.0% acetic acid and 10% acetonitrile at 25kV and 20℃.The relative standard deviations(R.S.D.)of the migration times and peak areas of the three active components were 0.06%-0.20% and 0.12%-3.41% for berberine,0.11%-0.60% and 0.74%-1.63% for matrine,0.15% and 0.45% for oxymatrine,respectively.Detection limits of berberine,matrine and oxymtrine were 0.18μg/mL,4.08μg/mL and 4.16μg/mL,respectively.In the tested concentration range,good linear relationships(0.9992 for berberine,0.9988 for matrine and 0.9988 for oxymatrine)were observed.The linear calibration ranges were 0.45-360.0μg/mL for berberine,8.16-408.0μg/mL for matrine and 20.8-416.0μg/mL for oxymatrine.This method has been successfully applied to the phytochemical analysis of alkaloids extracts from two commonly used traditional Chinese herbal drugs:Sophora flavescens Ait.(Kushen)and Cortex phellodendri chinensis(Huangbai)and their medicinal preparations.

Chiral Separation of Ibuprofen and Terbutaline by Nonaqueous Capillary Electrophoresis with Conductance Detection

In the nonaqueous N,N -dimethylformamide medium, the chiral drugs ibuprofen and terbutaline were successfully separated with sulfonyl- β -cyclodextrin(s- β -CD) as the chiral selector by capillary electrophoresis with conductance detection. The comparison of the effects of three CDS( β -CD, diethylic- β -CD, sulfonyl- β -CD) on the chiral separation was made and the resolution mechanism was proposed.

The Applicaton of IAF Theory to the Study of Dissociation Equilibrium (Ⅱ) --The Calculation of Solubility Product Constant in Nonaqueous Solvents

This article reports a theoretical calculation of solubility product constant of several slightly soluble silver salts in a number of nonaqueous solvents according to the IAF (interaction force) theory based on the interaction free energy of electrostatic, orientation, induction and dispersion. The calculated values of pKsp are in good accordance with those from literature.

Chiral Separation of N-Benzoyl Phenylalanine Methyl Ester by Nonaqueous Capillary Electrophoresis

A successful chiral separation of N-benzoyl phenylalanine methyl ester has been achieved by nonaqueous capillary electrophoresis (NACE) using P-CD as chiral selector in formamide (FA). Some experimental parameters influencing the chiral separation such as concentration of P-CD, ionic strength and apparent pH (pH*) are discussed.

An Equation of State for Nonaqueous Electrolyte Solutions

A two parameters equation of state (EOS) for nonaqueous electrolyte solutions system has been developed. The equation is in terms of Helmholtz free energy and incorporated with results of low density expansion of non-primitive mean spherical approximation. The EOS was tested for experimental data reported in literatures of 9 nonaqueous single electrolyte solutions of which the temperature was 298.15 K, and it also has a good predictive capability for nonaqueous electrolyte solutions at different temperature in this work. The comparisons with EOSs published earlier by other researchers in literatures are carried out in detail.

STUDY ON IMMOBILIZED PORCINE PANCREATIC LIPASE CATALYZING TRANSESTERIFICATION BETWEEN METHYL－BUTYRATE AND 1－BUTANOL IN NONAQUEOUS SYSTEMS

Transesterification between methyl-butyrate and 1-butanol in nonaqueous systems was catalyzed by porcine pancreatic lipase which was immobilized on cross- linked polystyrene. Organic solvents, substrate concentration, contents of water and other parameters which affect the immobilized enzyme activity were studied. Lipase immobilized on hydrophobic crosslinked polystyrene can reduce its diffusion limit in the reaction. It was found that the activity of immobilized lipase in organic systems was two times as high as that of free lipase.

Determination of Magnolol and Honokiol by Non-aqueous Capillary Electrophoresis

Two active principles in traditional Chinese medicine Magnolia officinalis, magnolol and honokiol, were successfully separated by means of nonaqueous capillary electrophoresis. The effect of the composition of a nonaqueous buffer on column efficiency and resolution, and the effect of acid additives on peak shapes were researched. The separation was conducted with a running buffer in a mixture of methanol/aeetonitrile/formamide （ volume ratio ： 1 ： 2 ： 2 ）, in which the concentrations of Tris, acetic acid, and water were 60 retool/L, 0. 04 mmol/L and 5% （ volume fration）, respectively, and the pH^＊ （apperent pH） of the running buffer was 8.96. Magnolol and honokiol were separated on baseline within 20 min. The relative standard deviation of the analytes＇ concentrations in the sample is 1.32% for magnolol and 1.60% for honokiol, and the recoveries of the spiked sample are 98.4% for magnolol and 98. 0% for honokiol, respectively.

Preparation of Macroporous TiO2 Ceramic Based on Membrane Jet-flow Emulsification

A novel method to prepare macroporous TiO2 ceramic, based on membrane emulsification was reported.To solve the paradox between the instability of nonaqueous emulsion and long emulsification time required by themembrane emulsification, a two-stage ceramic membrane jet-flow emulsification .was. proposed. Discussion wasconducted on the evolution of droplet size with time, which followed the Ostwalcl npemng theory. And a monodispersed nonaqueous emulsion with an average droplet size of 1.6μm could beprepared. Using the emulsion, as atemplate, TiO2 ceramics with an average pore size ot 1.1 μm were obtaineed. Tne material could be prospectivelyused for preparation of catalysts, adsorbents, and membranes.

Synthesis and Characterization of CoAPO-11 Molecular Sieve from a Non-aqueous System

CoAPO11 molecular sieve with a high crystallinity was prepared by hydrothermal synthesis from a nonaqueous system(EG)in the presence of Et2NH or iPr2NH as a structuredirecting agent.The Xray diffraction(XRD)patterns and scanning electron micrographs(SEM)revealed that the product powder was pure and homogenous in particlesize.The Xray powder diffraction data,compositional analysis,thermal stability analysis and UVVis diffuse reflectance spectroscopic analysis showed that Co()ions were incorporated in the aluminophosphate framework and tetrahedrally coordinated in the lattice of asprepared samples.

Hydroformylation of Oleyl Alcohol Catalyzed by Rh-OPGPP Complex

Polyether-tailored phosphite modified rhodium complex formed in situ was highly active in the hydroformylation of oleyl alcohol in nonaqueous phosphite/heptane system where the phosphite acted both as the ligand and the second phase. This catalyst was easily separated by simple decantation and can be used for five times with only a slight decrease in activity.

Studies on the Formation Mechanism of Silica-Sodalite in the System of Sodium Hydroxide-Silica-Ethylene Glycol

In 1985,Bibby and Dale first reported the synthesis of silica-sodalite from organic solvent such as ethylene glycol or propanol.In 1987, Van Erp and his coworkers reported the formation of crystalline aluminosilicates in organic solvents such as hexanol,glycol, glycerol, sulfolane and pyridine. Because the concepts effective in the aqueous synthesis cannot be simply applied to the nonaqueous media,the formation mechanism of zeolite in the nonaqueous system has not been investigated yet.

Synthesis of Large Crystal of NH4ZnPO4 from HOCH2CH2OH System

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Three-dimensional evaluation of inclusion particles in steel

The estimation of inclusion particles has a relation close to the control of steel grain growth as well as the production of clean steel.In present study,the electrolytic extraction methods using nonaqueous electrolyte have been examined for the extraction of various inclusion particles,in order to evaluate their three-dimensional morphologies and compositional segregations.The cross section of fine inclusion particle,which was prepared by focused ion beam method,was qualitatively analyzed using Auger electron spectroscopy.From the results obtained by this method,the formation mechanism of complex inclusion particle could be explained clearly.