氢化物发生-原子吸收光谱法快速测定锌电解料液中痕量砷

在盐酸介质中,Ａｓ（Ⅴ）用碘化钾和抗坏血酸还原成Ａｓ（Ⅲ）后,再与强还原剂硼氢化钾反应生成气态氢化砷。氢化砷用氮载气送入原子化系统原子化后进行测定,砷的最大吸了波长为１９３．７ｎｍ,在０．５－５０ｎｇ．ｍｌ＾－１范围内,砷浓度与吸光度呈线性关系,检出限为３．４＊１０＾９ｍｏｌ．Ｌ＾－１。方法毋需预处理直接用于锌电解料液中微量和痕量砷的测定,结果满意。     

固体电解质Li9-nxMn+xN2Cl3(M=Na、Mg、Al)的合成及表征

高温固相反应合成了固体电解质Li_(9-nx)M~(n )_xN_2Cl_3(M=Na、Mg、Al)。利用粉末 X射线衍射测定样品结构。测定了离子电导率 ,分解电压和电子电导。得出掺杂可以提高快离子导体材料 Li_9N_2Cl_3的电导率。并讨论了掺杂阳离子的半径和价态与替代离子的关系和影响。使用 x=0.05mol的二价镁离子替代 Li_9N_2Cl_3中的 Li＋离子可以很大程度的提高其电导率。     

Energetics of magnesium, strontium, and barium doped lanthanum gallate perovskites

LaGaO₃ perovskites doped with Sr or Ba at the La site and Mg at the Ga site were prepared by solid-state reaction or sol-gel method and characterized. Enthalpies of formation from constituent oxides at 298 K were determined by high-temperature oxide melt solution calorimetry. Energetic trends are discussed in terms of defect chemistry. As oxygen deficiency increases, formation enthalpies define three trends, LaGa_1−yMg_yO_3−δ (LGM), La_1−xSr_xGa_1−yMg_yO_3−δ (LSGM), and La_1−xBa_xGa_1−yMg_yO_3−δ (LBGM). They become less exothermic with increasing doping, suggesting a dominant destabilization effect from oxygen vacancies. The endothermic enthalpy of vacancy formation is 275±37, 166±18 and 138±12 kJ/mol of V_O^·· for LGM, LBGM and LSGM, respectively. Tolerance factor and ion size mismatch also affect enthalpies. In terms of energetics, Sr is the best dopant for the La site and Mg for the Ga site, supporting earlier studies, including oxygen ion conductivity and computer modeling.     

Structural investigation of (CuI)0.45–(Ag2WO4)0.55 solid electrolyte using X-ray photoelectron and laser Raman spectroscopies

X-ray photoelectron spectroscopy (XPS) and laser Raman scattering (LRS) techniques have been employed to investigate the structure of amorphous (CuI)_0.45–(Ag₂WO₄)_0.55 solid electrolyte sample. XPS results reveal the presence of both Cu⁺ and Cu²⁺ ions whereas tungsten is found to exist only in the oxidation state of +6. The deconvolution of the O 1s spectrum into non-bridging and bridging oxygen atoms in conjunction with the laser Raman analysis tend to show that the amorphous (CuI)_0.45–(Ag₂WO₄)_0.55 solid electrolyte sample is composed mostly of octahedral WO₆ units that probably form [W₄O₁₆]⁸⁻ tetramer clusters, the existence of which is unique in the case of oxyhalide glasses.     

Influence of nanoporous carbon electrode thickness on the electrochemical characteristics of a nanoporous carbon|tetraethylammonium tetrafluoroborate in acetonitrile solution interface

Electrochemical characteristics for the nanoporous carbon|Et₄NBF₄+acetonitrile interface have been studied by cyclic voltammetry and impedance spectroscopy methods. The influence of the electrolyte concentration and thickness of the nanoporous electrode material on the shape of the cyclic voltammetry and impedance curves has been established and the reasons for these phenomena are discussed. A value of zero charge potential, depending slightly on the structure and concentration of the electrolyte, the region of ideal polarizability and other characteristics have been established. The nanoporous nature of the carbon electrodes introduces a distribution of resistive and capacitive elements, giving rise to complicated electrochemical behaviour. Analysis of the complex plane plots shows that the nanoporous carbon|Et₄NBF₄+acetonitrile electrolyte interface can be simulated by an equivalent circuit, in which two parallel conduction paths in the solid and liquid phases are interconnected by the double-layer capacitance in parallel with the complex admittance of the hindered reaction of the charge transfer or of the partial charge transfer (i.e. adsorption stage limited) process. The values of the characteristic frequency depend on the electrolyte concentration and electrode potential, i.e. on the nature of the ions adsorbed at the surface of the nanoporous carbon electrode. The value of the solid state phase resistance established is independent of the thickness of the electrode material.     

锂磷氧氮(LiPON)薄膜电解质和全固态薄膜锂电池研究

采用电子束热蒸发Li₃PO₄与氮等离子体辅助相结合的方法制备了含氮磷酸锂(LiPON)电解质薄膜,已测得该非晶态电解质薄膜在温度为300K时的离子导电率为6.0×10^-7 S/cm,电子电导率低于10^-10 S/cm,电化学稳定窗口为5.0V.以脉冲激光沉积法(PLD)制备的非晶态Ag_0.5V₂O₅薄膜为阴极,真空热蒸发法制备的金属锂为阳极,LiPON薄膜为电解质,成功地制备了一个新的Li/LiPON/Ag_0.5V₂O₅全固态薄膜锂电池.该电池以14μA/cm²电流充/放电时,首次放电容量达到62 μAh·cm^-2·μm^-1,10次循环后容量衰减缓慢,衰减率约为0.2%,循环寿命达到550次以上.     

Heterogeneous continuous flow synthetic system using cyclohexane-based multiphase electrolyte solutions

The discovery that supporting electrolytes can be effectively confined in typical organic solvents in a c-Hex-based multiphase electrolyte solution has led to the development of a novel heterogeneous continuous flow synthetic system. PTFE fiber functions as a separation filter that can efficiently isolate the c-Hex phase from multiphase electrolyte solutions. This system has demonstrated both electrochemical solvating and carbon-carbon bond forming reactions. Hydrophobic substrates can be introduced into the reactor as c-Hex solutions, which are then electrochemically transformed into the target hydrophobic products that pass through the PTFE fiber as c-Hex solutions.     

Ion interaction approach to calculations of volumetric properties of aqueous multiple-solute electrolyte solutions

The ion interaction approach developed by Pitzer was used for the prediction of volumetric properties of mixed electrolyte solutions at 25°C based on parameters calculated from experimental data for single-solute electrolyte solutions. Such an approach was shown to be especially effective for application to the calculation of volumetric properties of natural hypersaline brines and of industrial electrolyte solutions of large complexity. The use of the latest recommended sets of volumetric ion interaction parameters for single electrolyte solutions and symmetrical mixing parameters for Na–K–Cl ion combinations considerably improved the precision of the density calculations of highly concentrated mixed electrolyte solutions and of various natural waters.     

Vapor pressure,speciation, and chemical activities in highly concentrated sodium borate solutions at 277 and 317°C

The system H₂O-B₂O₃-Na₂O has been studied experimentally at 277 and 317°C. The activities of water and boric acid have been determined at mole ratios Na/B from 0 to 1.5, and total dissolved solids 3 to 80 weight percent. The activity of boric acid has been fitted to within experimental error using a speciation model with eight complex species. This model is consistent with the model previously published by Mesmer et al. The electrolyte properties of the liquid are modeled using the Pitzer-Simonson model of very concentrated electrolyte solutions. The calculated values of water activity agree with experiment, and the activity of NaOH and pOH have also been calculated. The potassium borate system also was briefly studied at 317°C, and is adequately described by a model with five complex species. The potassium borate liquid is more alkaline at K/B= 1 than a sodium borate liquid at the same mole ratio, but pOH in the two systems is the same at lower mole ratios.