金属锂电极/有机电解液界面的研究进展

综述了金属锂二次电池中锂电极/液态有机电解液界面的研究进展。介绍了金属锂/有机电解液界面锂枝晶的形成原理和充放电制度对锂枝晶生长的影响,有机电解液组成以及锂合金添加剂对锂界面膜形貌、结构组成和电化学稳定性的影响,以及锂电极的界面膜形貌与循环性能之间的相互关系。基于1,3-二氧戊环溶剂的三氟甲基磺酸亚胺锂电解液,特别是掺杂Al3+、Mg2+、Ca2+等金属离子能显著增强锂电极界面膜的稳定性,提高金属锂电极的循环性能。     

The large gap case for HV insulation in vacuum

A test setup able to accommodate dish shaped electrodes for gaps up to ~20 cm is being used to study large gap effects. This experiment, in connection with other authors' experiments, underlines the three more characteristic aspects of the large gap case: a voltage effect, a current effect and a gas effect. The difficulty of energy dissipation by surface processes at increasing penetration depth of the energy deposit gives an interesting interpretative perspective to the behavior of large gap, HV devices     

Characteristics of creeping discharge developed in a narrow gap between insulators and effect of a backside electrode

Discharge characteristics have been investigated for a needle–plane electrode configuration containing insulating barriers with a narrow gap which has been placed between the needle and the plane. The characteristics of creeping discharge developed in the narrow gap of the barrier filled with SF₆ are especially considered. In the case of a configuration with a backside electrode below the needle, the corona generated from the needle easily extended to the gap. On the other hand, for a configuration without a backside electrode, the corona has hardly extended to the gap, and on increasing the applied voltage the corona developed greatly in the gap. This difference in corona extension should affect the flashover characteristics in the present system. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 146(2): 27–36, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10248     

Optimization of HV electrode systems by neural networks using a newlearning method

To avoid a large number of iterations, optimization of electrode shapes has been done by artificial neural networks (NN). Two practical examples have been considered, an axisymmetric single-phase GIS bus termination and an axisymmetric transformer shield ring. The shape of the electrodes has been taken as quarter-ellipse or half-ellipse because an ellipse has more flexibility than a circle. For NN, the so-called resilient propagation algorithm, learning faster than the standard back-propagation algorithm, has been employed. The training sets as well as the test sets of NN have been prepared by charge simulation method     

Fast electrostatic discharges between a charged thin dielectricfilm and a spherical electrode with or without dielectric coating

Short-gap (less than 1 mm) electrostatic discharge (ESD) between a charged thin dielectric film on an earthed-plate electrode and a spherical electrode, connected to the plate, with or without an uncharged thin dielectric film coating was observed. Discharge-current waveform, discharge gap length, current rise time, discharging photograph, and current peak value were recorded by the authors' measuring system. The initial charge supply effects by irradiation of β-ray or ultraviolet light were found to be not highly apparent; that is, the reproducibility of ESD experiments was not greatly improved. Surface-charge-polarity dependence of surface ESD between charged and uncharged dielectric films decreases with increase of the film thickness. The discharge gap length of ESD with a 1.5 μm uncharged film coating on the spherical electrode decrease to 50 or 70% compared with that between a charged film and a bare spherical metal electrode. Peak current and transferred charge value of ESD also decrease to roughly one-third of that between the film and the spherical electrode     

小分子燃料在Pt/HxMoO3电极上的催化氧化

钼酸盐在铂电极上硫酸溶液中还原形成钼青铜 ,吸附在电极表面 ,铂电极因钼酸盐的还原和钼青铜的氧化而得到修饰。研究甲醇、甲醛和甲酸在这种修饰铂电极上的催化氧化 ,表明修饰电极对甲醇、甲醛和甲酸的氧化有明显的催化作用     

Charge acquired by a spherical ball bouncing on an electrode: comparison between theory and experiment

A conducting ball immersed in a poorly conducting liquid between two horizontal plates acquires a charge when subjected to a dc voltage. When the applied voltage is high enough for the electric force to overcome gravity, the ball rises, moves up through the liquid and falls down as its charge leaks away. The threshold of voltage, as well as the time of flight between contacts, depends on the charge acquired by the ball during the contact with the electrode. Experiments have been done using liquids of different conductivities and it was shown that the conductivity does not affect the lift-off voltage. When the ball gets close to the electrode a discharge occurs and a current pulse is registered by the external circuit. The charge carried by the pulse is an order of magnitude smaller than the charge transferred to the ball from the electrode. We have made a detailed study, with different balls and liquids, of the charge transferred to the external circuit. The dependence on the different parameters of the ratio charge transferred to the circuit-charge acquired by the ball is explained using the coefficients of capacity of the electrostatic system.     

Vertical‐type organic device using thin‐film ZnO transparent electrode

We propose a double heterojunction organic light‐emitting diode (OLED) using a zinc oxide (ZnO) film, which works as a transparent and electron injection layer. The crystal structure of the ZnO films as a function of Ar/O₂ flow ratio and the basic characteristics of the OLED depending on the ZnO sputtering conditions are investigated. Excellent characteristics of the novel OLED were obtained, as high as 470 cd/m² at 22 V and 7.6 mA/cm². The results obtained here demonstrate that the vertical organic light‐emitting transistor (OLET) using a ZnO layer as an electron injection layer is promising as a key element for flexible sheet displays. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 158(2): 49–55, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20151     

Improvement of electrode/organic layer interfaces by insertion of monolayerlike aluminum oxide film

We studied improvement of the electrode/organic interface in organic electroluminescent diodes which consist of 8‐hydroxyquinoline aluminum (Alq₃) and diamine derivative (TPD). An aluminum oxide (Al₂O₃) monolayer was inserted between TPD and the indium tin oxide (ITO) anode. An improvement of emission is observed in a diode with an Al₂O₃ layer between 0.5 and 1 nm thick inserted in the surface of the anode/organic layer. The mechanism of increase in emission efficiency is discussed. © 2000 Scripta Technica Electr Eng Jpn 132(3): 14–18, 2000     

金属氢化物负极研究进展

碱性MH/Ni电池中贮氢电极的研究和应用有较长的历史,无论在理论研究还是实际应用上都取得了长足的进步。近年来,随着MH/Ni电池的成功开发和应用,尤其是MH/Ni动力电池应用,MH电极的性能受到了人们的极大关注。综述了MH电极活性物质的结构、物理化学性能及其制备方法、电极的制备工艺、电极热力学与动力学等方面的内容。     

Relationship between electrode surface roughness and impulse breakdown voltage in vacuum gap of Cu and Cu-Cr electrodes

The relationship between the impulse breakdown voltage of vacuum gaps and electrode surface roughness was investigated for the purpose of controlling the surface roughness on HV conductors. The roughness of mechanically polished Cu and Cu-Cr electrodes was measured with a roughness meter, and the relationship between the breakdown voltage and surface roughness was obtained for plate-to-plate gaps. The discharge-conditioning effect increased with reduction in the surface roughness. The breakdown voltage depended not only on the roughness of the cathode but also on the anode surfaces. Reducing the surface roughness was found not to be an effective way to increase the breakdown voltage for non-uniform field gaps after discharge conditioning.     

Switching characteristics of a triggered vacuum gap employing a trigger electrode in the respective main electrodes

Both switching time and minimum firing voltage of a triggered vacuum gap employing a trigger electrode in the cathode and anode (double triggered vacuum gap) were measured. The double triggered vacuum gap was operated below 100 V independent of the high voltage main electrode polarity (positive or negative). This minimum firing voltage was lower than that of the conventional triggered vacuum gap. The switching time is approximately 0.5 μs in the range 3 to 18 kV. The conventional triggered vacuum gap has a trigger electrode that is placed at the center of the grounded main electrode. The polarity of the main electrode affected switching time characteristics. A trigger electrode was added to the high voltage main electrode. The double triggered vacuum gap was only slightly influenced by the polarity of the high voltage main electrode when both main electrodes were triggered at the same time.     

普鲁士蓝薄膜电极的制作及充放电研究

以多孔阳极氧化铝作电极活性物质的支撑体,制备了一种新型的普鲁士蓝薄膜电极。制备过程包括纯铝片在草酸溶液中阳极氧化成多孔阳极氧化铝,电化学法去多孔阳极氧化铝的阻挡层,磷酸中扩孔,无电沉积一层钯,再在孔中组装普鲁士蓝。用扫描电镜对支撑体和电极表面形貌进行了表征,用循环伏安法对电极进行了电化学研究。结果表明,这种支撑体孔隙率大于65%,组装的普鲁士蓝(PB)薄膜电极在-0.2～0.6V和0.6～1.2V两个电位窗口内呈现两对稳定的可逆峰,由这种薄膜电极组成的微型PB薄膜蓄电池,容量达到65mC/cm2,表现出良好的充放电性能。     

锂离子电池用金属锡电极的初步研究

采用电镀法制备得到金属锡电极 ,用于锂离子电池中作为负极材料 ,并通过循环伏安和电性能测试对其进行初步研究。研究发现金属锡的嵌锂过程分为两步进行 ,分别为 0 .5V级的由金属锡嵌锂变为贫锂相 [LixSn(x <2 .3 3 ) ] ;0 .3V级的由贫锂相变为富锂相 (LiySn(2 .5 相似文献   

The effect of the electrode gap on breakdown in liquid dielectrics

It is a well known fact that the breakdown voltage of an insulating liquid increases nonlinearly with increasing electrode gap. Under nonuniform field dc conditions two breakdown voltages are determined depending on the electrode polarity. Using point-plane geometries, with gaps of 5 mm or larger, one finds that typical transformer oils have higher breakdown voltages when the point is negative than when it is positive. Recently, perfluorinated polyethers have been found to produce opposite results when using average gap sizes of 5 to 10 mm. To elucidate this situation a study of the effect of gap size on breakdown voltage has been undertaken. The results show that for the polyethers at larger gaps the sequence is reversed. These observations are explained in terms of the respective streamer developments in these liquids and the relative stability of their negative ions. In the case of the conventional hydrocarbon type oils, the positive streamer usually grows slightly faster than the negative one, but the streamer inception voltages of both are rather similar. In the case of perfluorinated polyethers the positive streamers move at least 10× faster than the negative ones, but they require much higher inception voltages than negative ones. At gaps ≳12 mm and the associated higher applied voltages this breakdown at negative polarity occurs at higher voltages than at the positive one. The negative ions of the perfluoro compounds are much more stable than those of conventional hydrocarbons. The discharge of the negatively charged perfluoro ions requires much higher fields than do those of conventional hydrocarbons. The implications of these observations are discussed in some detail     

Impact of semiconductor/metal interfaces on contact resistance and operating speed of organic thin film transistors

The contact resistance of field effect transistors based on pentacene and parylene has been investigated by experimental and numerical analysis. The device simulation was performed using finite element two-dimensional drift-diffusion simulation taking into account field-dependent mobility, interface/bulk trap states and fixed charge density at the organic/insulator interface. The width-normalized contact resistance extracted from simulation which included an interface dipole layer between the gold source/drain electrodes and pentacene was 91 k??cm. However, contact resistance extracted from the simulation, without consideration of interface dipole was 52.4?k??cm, which is about half of the experimentally extracted 108?k??cm. This indicates that interface dipoles are critical effects which degrade performances of organic field effect transistors by increasing the contact resistance. Using numerical calculations and circuit simulations, we have predicted a 1?MHz switching frequency for a 1???m channel length transistor without dipole interface between gold and pentacene. The transistor with dipole interface is predicted, via the same methods, to exhibit an operating frequency of less than 0.5?MHz.     

The effect of electrode material and additives on the breakdownstrength of a vacuum gap

The influence of additions of tungsten and cobalt into CuCr contact materials on the dielectric strength of a vacuum gap is investigated. Experimental results show that the dielectric strength increases significantly when the chromium phase in CuCr materials is selectively strengthened. The proper preparation method that determines the distribution of alloying elements is also suggested in this paper     

电极材料球形Ni(OH)_2中氨的测定

用改进的纳氏光度法测定ＭＨ－Ｎｉ电池正极材料Ｎｉ（ＯＨ）２中残留的氨的量。实验中研究了络合剂ＥＤＴＡ的用量和ｐＨ对氨回收率的影响。结果表明：ＥＤＴＡ的量对氨的回收率有影响。而在碱性条件下,待蒸溜溶液的初始ｐＨ值对回收率影响不大,本方法的回收率为９５％～１０５％,相对标准偏差为３．１％,适合Ｎｉ（ＯＨ）２中氨的测定     

Electric field and space charge of spherical electrode at highvoltage concentric with a grounded conductive sphere

The solution of the space-charge Poisson's equation is presented for a spherical electrode at high voltage concentric with a grounded conductive sphere. The obtained electric field is given in terms of the ion current emitted by the electrode and an integration constant. Both parameters are functions of boundary conditions. Using measured values of the ion current for a range of boundary conditions and applying these boundary conditions to determine the integration constant suggest a minimum value for the ion mobility of 1.9×10^-4 m² /V.s. Approximate formulas for the ion current and the electric field in terms of the independent parameters were also developed. Also, it was shown that this spherical system with its solution can be used to make accurate evaluation of the ion mobility. The obtained solutions can be applied with good approximation to many practical electrostatic systems involving point electrode at high voltage generating ions. Although the subject matter is very general and could have a fundamental research aspect, in this paper, it is meant to be applied to the area of electrostatic powder paint coating. Therefore, all the examples of boundary conditions and illustrations are typical of the electrostatic powder paint coating     

10kV金属铠装封闭式开关柜静触头发热缺陷分析

发热点属于开关内的静触头松动和引下线与母线连接面接触不良,造成氧化后长时间过热而造成损坏,其热量是会通过空气介质传播到开关柜表面的,此时如果通过对开关柜表面的温度场进行横向和纵向的比较。