薄层液膜下金属电化学腐蚀电池的设计

设计了一种研究金属在薄层液膜下电化学行为的三电极腐蚀电池.该电池在降低研究电极和参比电极之间IR的同时消除了参比电极中离子对薄层液膜的污染,并且易于操作.通过稳态极化曲线和交流阻抗技术研究了该电池在薄层液膜下和在大量电解质溶液中的电化学行为,证明了该电池适合研究金属在大气中的电化学腐蚀行为.     

A quartz crystal microbalance study of the electrochemical reaction at the interfaces of Platinum/Aqueous solution and Iron/Aqueous solution

The adsorption of the sulphate ions on the platinum electrode in sulphuric acid solution and the breakdown of the passivity in the iron electrode in the chloride-containing and chloride-free alkaline solutions have been investigated by usingin-situ electrochemical quartz crystal microbalance (EQCM) technique combined with cyclic voltammetry (CV), potentiodynamic polarization and potentiostatic current transient techniques. In the case of the platinum electrode, the combined electrogravimetric and voltammetric results are indicative of the onset of the adsorption of the sulphate ions at an applied potential between the two characteristic potentials of hydrogen desorption, above which the adsorption occurs. The adsorption of the sulphate ions was quantitatively analyzed with cyclic electrogravimetric data combined with those determined from radio tracer technique and Fourier transform infra-red (FTIR) spectroscopy by other researchers. In the case of the iron electrode, the electrogravimetric data obtained simultaneously with the potentiodynamic polarization data indicate the pitting and high-voltage breakdown of the oxide film in the chloride-containing and -free solutions, respectively. Preventing the crevice corrosion from occurring around the O-ring at the quartz crystal, the electrogravimetric curve showed that the pit initiation time measured by EQCM coincides with that time determined by current transient experiment.     

大气腐蚀电化学研究方法现状

综述了大气腐蚀的电化学研究方法，尤其是薄液膜下 的电化学交流阻抗(EIS)和Kelvin探针技术的应用，比较了不同方法的优缺点.EIS比较适合 于研究薄液膜下金属的腐蚀历程；Kelvin探头适合于研究金属表面的局部腐蚀.最后展望了 大气腐蚀的研究趋势.     

Application of Electrochemical Quartz Crystal Microbalance Technique to Hydrogen/Lithium Insertion into MnO2/LiCoO2 Electrode in Aqueous/Non-aqueous Solution

The hydrogen insertion/desertion into/from MnO₂ electrode in aqueous solution and the lithium intercalation/ deintercalation into/from LiCoO₂ electrode in non-aqueous solution have been investigated by usingin-situ electrochemical quartz crystal microbalance (EQCM) technique combined with cyclic voltammetry (CV) and galvanostatic charge-discharge experiment. In the case of the MnO₂ electrode, the combined cyclic electrogravimetric and CV results indicated that the redox potentials at the transition in oxidation state of manganese ion measured on the cathodic scan are satisfactorily in accord in value with those thermodynamic e-quilibrium potentials calculated in Pourbaix diagram. The positive/negative slope with a constant value in the plot of mass change rate vs. potential means that the reaction is inclined to proceed in the direction of an oxidation/reduction between two phases. From the electrogravimetric curves obtained simultaneously with galvanostatic discharge curves, the discrepancy between the charge and mass variations was discussed in relation with the hydrogen-induced stress. In the case of the LiCoO₂ electrode, the cyclic electrogravimetric data obtained simultaneously with CV indicated that neither solvent nor any of other species but lithium ions are intercalated into and deintercalated from the electrode. From the cyclic electrogravimetric curve obtained simultaneously with galvanostatic charge-discharge curve, the discrepancy between the charge and mass variations was discussed in relation with the change of the molar volume and surface roughness of the electrode during the lithium intercalation and deintercalation.     

使用Kelvin探头参比电极技术进行薄液层下电化学测量

研究了Ｋｅｌｖｉｎ探头参比电极技术测定薄液层下金属电化学行为的方法。为改善Ｋｅｌｖｉｎ探头装置的测试性能，采取和若干提高信噪比的措施，如采用压陶瓷振动驱动器和测量交流信号的电压成分等。实验结果表明，改进的这套装置可用于测试极薄液层下的金属电极电位，电位随时间的变化，腐蚀电位分布及极化曲线等稳态电化学行为，是研究大气腐蚀过程的有效工具之一。     

Charge-discharge induced phase transformation of RuO<Subscript>2</Subscript> electrode for thin film supercapacitor

We report on the preparation of an all solid-state thin film micro-supercapacitor using RuO₂ electrode film and LiPON electrolyte film on a Pt/Ti/Si substrate with dual target dc and rf reactive sputtering. Room temperature charge-discharge measurements based on a symmetrical RuO₂/LiPON/RuO₂ structure clearly demonstrated the cyclibility dependence of the RuO₂ electrode on the microstructure. Using both glancing angle X-ray diffraction (GXRD) and transmission electron microscopy (TEM) analysis, it was found that the characteristics of the thin film supercapacitor are dependent on the microstructure of the RuO₂ film. In addition, high-resolution electron transmission microscopy (HREM) analysis after cycling demonstrates that the interface layer formed by interfacial reaction between the LiPON and RuO₂ acts as the main factor in the degradation of the performance of the thin film micro-supercapacitor. This article is based on a presentation made in the 2002 Korea-US symposium on the “Phase Transformations of Nano-Materials”, organized as a special program of the 2002 Annual Meeting of the Korean Institute of Metals and Materials, held at Yonsei University, Seoul, Korea on October 25–26, 2002.     

LiPON固体电解质膜对金属锂电极的保护作用

制备LiPON固体电解质薄膜,通过电沉积手段获得由LiPON膜保护的金属锂电极,测试该电极在有机电解液体系中的电化学性质。结果表明：LiPON膜的存在,抑制了锂电极和电解液之间的非法拉第反应,使锂电极具有更加稳定的电极/电解液界面。由于LiPON膜的保护作用,金属锂电极在充放电循环中也表现出优越的界面稳定性,从而获得更高的库伦循环效率和更好的电池循环寿命。     

Li-Si合金中间相作为锂离子电池负极材料的研究

采用基于密度泛函理论的第一性原理平面波赝势方法计算了Li-Si各种合金相的物理性质和电化学性能。结果表明：除了在反应过程中生成传统的固态电解质SEI膜之外,形成的Li12Si7合金相也是部分导致首次不可逆容量损失的重要原因。另外,采用射频磁控溅射制备了纯Si薄膜电极,并运用XRD、循环伏安CV、恒流充放电CC表征和测试了材料的结构和电化学性能,结果表明首次不可逆容量损失非常大,无定型结构能有效抑制体积膨胀和改善循环性能     

Kelvin探头振动电容法技术在大气腐蚀中的应用

介绍了Kelvin探头振动电容法在腐蚀中的应用原理及试验装置,Kelvin探头(也称为振动电容法)技术应用到金属腐蚀的研究中,可以在不需与被测试样表面相接触的条件下,用Kelvin探针作参比电极,测量液膜下金属的腐蚀速率,电极电位及极化曲线.     

质子交换膜燃料电池金属双极板材料研究进展

双极板在质子交换膜燃料电池(PEMFC)中具有隔离反应介质、收集电流、提供气体通道的作用，金属材料用于双极板面临腐蚀及表面层钝化影响电池性能等问题．在介绍了研究金属双极板性能的方法，包括接触电阻测试、电池极化性能测试、模拟电化学方法等测试方法的同时，着重介绍了在双极板中应用的不同种类铁基金属材料、轻金属材料的性能及各种表面涂层技术的研究进展．简单介绍了PEMFC中，金属双极板材料研究所应重点解决的技术问题．     

Mg—Ni THIN FILM—A POTENTIAL NEGATIVE ELECTRODE FOR NIKEL—METAL HYDRIDE BATTERY

Mg-Ni thin films for nickel-metal hydride (Ni-MH) battery negative electrode were prepared on three different substrates by using magnetron sputtering with compacted Ni and Mg mixture powder. The microstructure of Mg-Ni thin films deposited on the glass and the Ni foil substrate respectively was studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that the Mg-Ni thin films were in amorphous structure and the composition of the thin film was homogeneous. Electrochemical measurement show the discharge capacity of the thin film negative electrode deposited on the foam Ni substrate was 284.8mAh/g in 6M alkaline electrolyte and the internal resistance was much lower than that of the electrode prepared by the ball-milled powder during the charge-discharge cycle.     

1,3-dioxolane pretreatment to improve the interfacial characteristics of a lithium anode

1,3-dioxolane （DOL） was originally used to pretreat a lithium metal electrode to improve its interfacial characteristics. Electrochemical impedance spectra （EIS） meastLrements revealed that, after the DOL pretreatment, the lithium electrode had better interfacial stability during immersion in electrolyte and as repeated charge/discharge cycles. It was proved by SEaM that the pretreated one has smoother morphology and less dendrite after repeated charge/discharge cycles. Consequentially, benefiting from the better interface characteristics of the lithium electrode, the rechargeable lithium cell with a DOL-pretreated lithium anode had the obviously enhanced discharging performance and better cyclability.     

采用丝束电极研究防锈油膜的防护性能

将１０１根金属丝聚集成束，制成一种检测防锈油膜防护性能的新型测试电极，测定了涂油丝束电极的腐蚀电位和油膜电阻的分布。结果表明，腐蚀电位分布服从非连续二基分布。油膜极化电阻分布服从对数正态分布。     

A Digital Microreflectometrical Video 3D-Probe for the Corrosion Studies

A reflectometrical video microprobe method for studying three-dimensional (3D) structures in spatially nonuniform surface films at metal/electrolyte interfaces is described. By forming microscopical video image of a probe microsite on the electrode surface and measuring the intensity distribution for reflected optical signal over the image area, one can obtain, in a real time, a three-dimensional image of the relief, thickness, and properties of islets, nuclei of a new phase, and secondary deposits over the selected area on the electrode surface. Practical considerations on developing an inexpensive PC-controlled microscopical video probe setup are given. The method is tested in a nondestructive study of microtopography of corrosion films formed on X18H10T chromic steel during its corrosion in iron chloride solution. The method is sensitive to thin films; it provides highly informative control of tangential nonuniformity of the film thickness over the studied microsite on the surface.     

The study on interfacial bonding strength of Ag-Ni, Ag-Cu in cold pressure welding

The area of combination actually is a kind of interfacial phenomena that exist on the surface or thin film. The properties of interface have important effect on the whole welded joint, even decide directly the interfacial bonding strength.The bonding strength of metals in cold pressure welding such as Ag-Ni (they are hardly mutual soluble ) and Ag-Cu( they are limited soluble ) are discussed in this paper. The results of the tensile test suggest that two kinds of welded joints have enough strength to satisfy with the demand for being used. Moreover, thermodynamics, crystal logy, physics and metal electronic microscopic analysis etc are adopted to further calculate the bonding strength. The results of test and theoretical analyses prove that Ag-Ni, Ag-Cu, especially, for Ag-Ni can .form strong welded joint which is higher than that of the relative soft base metals in cold pressure welding.     

Mechanismen der Korrosionsinhibition im Vergleich zu den Inhibitionsmechanismen anderer Elektrodenreaktionen

Corrosion inhibition mechanisms as compared to the inhibition mechanisms of other electrode reactions The corrosion inhibition is a special case of the inhibition of electrochemical electrode reactions. During any reaction of this nature - with or without impressed current - partial reactions may be inhibited by boundary face, electrolyte film or membrane inhibitors. The boundary face inhibitors are most efficient in acid or alkaline media, while membrane inhibitors are most efficient in approximately neutral media. The former — because of electrosorption at the metal/electrolyte boundary face - affect the electrochemical charge exchange or heterogeneous chemical partial reactions, while membrane inhibitors inhibit all the partial reactions by building a threedimensional surface layer. The electrolyte film inhibitors inhibit mass transfer to or from the metal/electrolyte boundary face, or they inhibit homogeneous chemical partial reactions either mechanically (by colloids or suspensions) or electrochemically (by modifying the surface charge of the metal and thus the tranfer velocity of ions by increasing attraction or repulsion). The use of passivators is restricted exclusively to corrosion inhibition. The passivating layers formed by them are much thinner and denser than the layers formed by membrane inhibitors. The passivators act like boundary surface inhibitors.     

Anion incorporation and migration during barrier film formation on aluminium

Surface analysis, using Auger electron spectroscopy with ion etching, and direct electronoptical examination have been employed to determine the relative contributions to solid film development during anodizing of aluminium, initially supporting a xenon implanted thin alumina film, in individual electrolytes containing phosphate, oxalate and chromate species. Under the anodizing conditions selected, film formation in the phosphate and chromate electrolytes proceeds at the metal/film and film/electrolytes interfaces, by O²⁻/OH⁻ ion ingress and Al³⁺ egress, respectively. In the oxalate electrolyte, little or no contribution to solid film growth is evident at the film/electrolyte interface, migrating Al³⁺ ions being ejected directly into the bulk electrolyte at that interface. Both phosphate and oxalate species are incorporated within the film material and are subsequently mobile inward under the field. Their respective migration rates are lower than that of O²⁻/OH⁻ ions such that a region of film material, free of the anion of the forming electrolyte, is developed adjacent to the metal/film interface.     

Kelvin探头参比电极技术在大气腐蚀研究中的应用

Kelvin探头参比电极技术是近年来大气腐蚀领域中最为活跃的研究方向之一．它能够不接触、无破坏的检测薄液膜甚至涂层下金属表面的腐蚀电位分布，文中介绍了该技术的发展历史、技术要点，着重讨论了该技术在研究金属表面有机涂层的剥离和薄液层下金属的腐蚀两方面的应用。     

TiO2/ITO膜的液相沉积法制备及其用于4-氨基安替比林降解的光电催化活性

利用液相沉积（LPD）法在ITO表面制备TiO2薄膜。光电流和交流阻抗（EIS）测试表明,这种TiO2/ITO液相沉积膜具有良好的光电性能,对紫外光产生灵敏、快速的电流响应,在此膜电极上通过施加一定的阳极偏压可有效分离光生电子-空穴对。将TiO2/ITO膜用于4-氨基安替比林的光电催化降解研究,与其他方法相比,利用此液相沉积膜电极的光电催化技术对于4-氨基安替比林的降解具有明显的协同效果,适合于该污染物的降解处理。当外加阳极偏压为＋0.8 V,支持电解质Na2SO4浓度为0.1 mol/L,溶液pH为2.0时,0.1 mmol/L 4-氨基安替比林120 min的光电催化降解效率最高可达95%。     

线性回归法进行Kelvin电位测试

采用线性回归方法确定Kelvin电位,以克服交流信号在零振幅点附近误差的影响.实验结果表明用该法设计的Kelvin探针装置可进行薄液层下金属电极电位测量和在有、无涂层下金属表面电位分布的测试.