Structure and Properties of Ti-Si-N Coatings Synthesized by Combining Cathode Arc and Middle-frequency Magnetron Sputtering

Ti-Si-N composite coatings were synthesized on a novel combining cathode and middle-frequency magnetron sputtering system, designed on an industrial scale. Ti was produced from the arc target and Si from magnetron target during deposition. The influences of negative bias voltage and Si content on the hardness and microstructure of the coatings were investigated. The composite coatings prepared under optimized conditions were characterized to be nc-TiN/a-Si3N4 structure with grain sizes of TiN ranging from 8-15 nm and exhibited a high hardness of 40 GPa. The enhancement of the hardness is suggested to be caused by the nanograin-amorphous structure effects.

Effects of Sputtering Parameters on the Performance of Sputtered Cathodes for Direct Methanol Fuel Cells

Plasma sputtering deposition techniques are good candidates for the fabrication of electrodes used for direct methanol fuel cells （DMFCs）. A house-made plasma sputtering system was used to deposit platinum of 0.1 mg/cm^2 onto un-catalyzed gas diffusion layers （GDLs） to form a Pt catalyzed cathode at different radio frequency （RF） powers and sputtering-gas pressures. The sputtered cathodes were assembled in custom-made membrane electrode assemblies （MEAs） with a commercial anode and tested for the electrical performance of the single cell. A custommade MEA with a sputtering prepared cathode was compared with that of a reference membrane electrode assembly made of commercial JM （Johnson Mattey） catalysts （Pt loading per electrode of 0.5 mg/cm^2） under passive methanol supply, ambient temperature and air-breathing conditions. The results showed that the cathode prepared at an input power of 110 W and sputtering-gas pressure of 5.3 Pa exhibited the best cell performance and highest Pt utilization efficiency, which was due to the miniaturization of the Pt particles and formation of the porous catalyst layer. Although the single cell performance of the commercial cathode was better than all the sputtering fabricated cathodes, the Pt utilization efficiency of all the sputtered cathodes was higher than that of the commercial cathode.

STUDY ON THE TANTALIZING ON THE SURFACE OF TITANIUM ALLOY BY NET-SHAPE CATHODE GLOW DISCHARGING

A new net-shape cathode sputtering target which has a simple structure and a hig h sputtering was put forward. The multiple-structure made of alloying and coatin g layers of tantalum was achieved on the surface of TC4 (Ti6Al4V) using this met hod in double glow surface alloying process. The tantalized samples were investi gated by SEM, XRD and electrochemical corrosion method .Results show the complic ated tissue of pure tantalizing layer and diffusion layer was successfully forme d on the surface of TC4 with the method of net-shape cathode glow discharge, whi ch further improved the corrosion-resistance of TC4 and formed good corrosion-re sistant alloys.

Crystallization of NiTi shape memory alloy sputtering-deposition film

The crystallization of NiTi shape memory alloy sputter deposition film in the course of sputtering deposition and that after heat treated were studied. The relationship between the process factors, such as substrate type, temperature, as well as the crystallization when heat treated after plating was investigated. The results show that a new phase precipitates during heat treatment after sputtering deposition and the degree of crystallization among different layers and the stress in grains are obviously different.

Physical and Electrochemical Characterization of LiCo0.8M0.2O2 （M=Ni,Zr） Cathode Films for All-solid-state Rechargeable Thin-film Lithium Batteries

LiCo0.8M0.2O2 （M=Ni,Zr） films were fabricated by radio frequency sputtering deposition combined with conventional annealing methods. The strtuctures of the films were characterized with X-ray diffraction （XRD）, Raman spectroscopy and scarming electron microscopy （SEM） techniques. It was shown that the 700 ℃- annealed LiCo0.8M0.2O2 has an α-NaFeO2 like layered structure. All-solid-state thin-film batteries （TFBs） were fabrieated with these films as the cathode and their eleetroctemical performances were evaluated. It was found that doping of electrochemically active Ni and inactive Zr has different effects on the structural and elcctrochemical properties of the LiCoO2 cathode films. Ni doping increases the discharge capacity of the film while Zr doping improves its cycling stability.

OBSERVATION ON SPUTTERING SURFACE OF ALLOYS IN GLOW DISCHARGE

Glow discharge cathodic sputtering of alloys containing second phase precipitates or injected oxide particles has been observed with energy dispersive X-ray spectrometer and scanning electron microprobe.It was shown that the formation of cones during the sputtering in these alloys is due to masking of the matrix by glow sputtering second phase precipitates or oxide particles.At steady state,the density of cottes were found to be a function of the densities pre- cipitates or oxide particles in bulk alloy.In addition to the changes of local sputtering rate,the electrostatic effect may play a role on the formation fo cones.

Self-Adjusting Characterization for Steady-State, Direct Current Cathode-Dominated Glow Discharge Plasmas at High Pressures

A steady-state,direct-current high-pressure CH_(4)-H_(2) glow discharge in a cup-shaped cathode parallel to anode configuration is investigated by using their V–I characteristics and CCD images.The discharges display an abnormal glow feature,and an expansion of a negative glow is observed on the cathode sidewall with the increasing discharge current.There exists a dependence of voltage on gas pressure for different fixed currents.The voltage decreases with gas pressure initially,and then increases conversely,which is correlated with the glow states of the cathode sidewall.This study exhibits a self-adjusting characterization for plasmas in cathode fall,which is important for maintaining steady-state,abnormal glow discharge in a relatively high pressure range.

Influence of the Iron Anisothermal Sintering on the Characteristic of the Hollow Cathode Discharge

This work studies the influence of anisothermal iron sintering process on hollow cathode discharge characteristics. Two independent cathodes form an annular discharge. The pressed cylindrical iron powder sample, acting as central cathode, was placed concentrically in the interior of an external cathode. The external cathode, machined from an AISI 310 steel bar, besides acting to confine the geometry of the plasma, can also acts as a source of alloying elements. The sample heating is a function of the ion bombardment energy and, so, of the discharge electrical parameters: current (or current density) and the effective potential applied to the cathode. Successive anisothermal sintering is performed in a same sample until the reproducibility of the electrical parameters being obtained. The heating experiments up to 1250 °C, in a gas mixture of 80% Ar + 20% H2, at pressure of 133 Pa, at flow of 2xlO"6 mV, with an inter-cathode radial space of 5.8 mm, were carried out. It was verified the metallurgical evolution of the iron sample sintering process influences the current-?0n (time switched-on of the pulse) characteristics of the discharge.

Simulation of plasma properties in magnetron sputtering for two kinds of cathode targets

Introduction During magnetron sputtering process,the common structure of cathode target is planar target and cylindrical rotating target.In this study,cylindrical rotating target is used and two kinds of cathode targets were investigated by COMSOL Multiphysics software(The official network of COMSOL Multiphysics software.https://uk.comsol.com/).We will elucidate the difference between the two types of cathode target and determine the type of cathode target used in the final experiment.The system configuration We explore the plasma distribution in the radio frequency cavity,so the simulation process was divided into two steps:building RF cavity model and setting up plasma discharge parameters.The main part of the model included the radio frequency cavity substrate(divided into two tube parts and middle ellipsoid part),the cathode and the magnet.And the plasma discharge parameters are as follows:Ar gas was used with 1.5 Pa;magnetic field strength of iron core was set to 1000 Gs;the applied voltage of cathode was set to-160 V;and anode was set to 0 V.Conclusion For the long cathode target and the short cathode target,the main difference is the electric field distribution.Because the electric field lines are denser for the long cathode target,the electric field intensity is stronger,and then the initial energy obtained by electrons is higher.During the plasma discharge process,because of the high electron energy,the plasma density produced is more than the simulation of the short cathode target.And under the same simulation time,the residual energy of electrons is more for the long cathode target,which is the reason for the higher electron temperature.From the previous experimental experience,we know that the film quality formed by higher electron energy is better.The simulation in this work shows that the electron energy corresponding to the long cathode target is higher than that of the short cathode target,so we choose the long cathode target as the experimental target in the subsequent coating experiments.

Microstructures and transformation characteristics of thin films of TiNiCu shape memory alloy

Both sputtering conditions and crystallizing temperatures have great influence on the microstructures and phase transformation characteristics for Ti 51 Ni 44Cu 5. By means of the resistance temperature measurement, X ray diffraction and atomic fore microscopic study, the results indicate that the transformation temperatures of the thin films increase and the "rock candy" martensitic relief is more easily obtained with promoting the sputtering Ar pressure, sputtering power, or crystallizing temperature. However, when sputtering Ar pressure, sputtering power, or crystallizing temperature are lower, a kind of "chrysanthemum" relief, which is related with Ti rich GP zones, is much easier to be observed. The reason is that during crystallization process, both of the inherent compressive stresses introduced under the condition of higher sputtering pressure or higher crystallizing temperature are helpful to the transition from GP zones to Ti 2(NiCu) precipitates and the increase of the transformation temperatures. The addition of copper to substitute for 5% nickel in mole fraction can reduce the transformation hysteresis width to about 10 ～ 15?℃.

Characterization of sputter-deposited TiPdNi thin films

TiPdNi thin films were prepared by magnetron sputtering onto unheated glass and silicon substrate. Atomic force microscope, energy dispersive X ray microanalyzer, X ray diffractometer, differential scanning calorimeter and optical microscope were used to characterize the films. It is found that the surface morphology of the films change during the sputtering process and a shift of about 3%Ti(mole fraction) content from the center to the edge of the substrate occurs. The freestanding as deposited films undergo crystallization followed by three kinds of cooling conditions. For all these heat treated films, B2→B19→B19′ two stage phase transformation takes place. Many Ti 2Ni and Ti 2Pd type of precipitates are detected in the films. The constraint films on silicon substrate are crystallized at high temperature. After crystallization, the films show a two way shape memory effect.

磁控溅射用旋转阴极磁场装置的结构设计及磁场分析

针对现有磁控溅射装置在镀膜工作中靶面阴极磁场分布不均匀的问题,设计了一种新型旋转阴极磁场装置。该装置通过旋转机构带动磁场做圆周运动,利用凸轮机构使磁场做上下直线运动。首先,利用3D软件绘制出该装置的三维模型;其次,对阴极磁场磁感应强度进行了有限元分析;最后,通过调整磁轭高度、伸出臂长度以及磁轭-靶材间距优化了磁场,并将优化前后的数值模拟曲线进行了对比分析。结果表明,优化后阴极磁场磁感应强度曲线的均匀度由21%改善到6%,有效改善了靶面磁场均匀性,有利于保证磁控溅射的稳定运行。

磁控溅射制备LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)薄膜工艺研究

目的探究了磁控溅射法制备符合化学计量比且循环性能良好的LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)薄膜工艺,有利于进一步提高全固态薄膜电池能量密度。方法从溅射功率、氩氧比、衬底温度中各选取3个水平组成L9(34)正交试验,在不锈钢衬底上沉积制备NCM811薄膜。利用X射线衍射仪和扫描电子显微镜对薄膜进行表征。利用EDS和ICP对薄膜成分进行分析。利用蓝电测试系统对以NCM811为正极的电池进行循环曲线测试。结果根据极差分析结果发现,影响前50圈放电容量保持率的因素从大到小依次为:温度>功率>氩氧比。其中功率和温度对循环性能有很大的影响,极差R值分别为18.45和26.79;氩氧比对循环性能影响较小,极差R值为3.17。增大溅射功率、提高衬底加热温度、增加氩氧比中氩气的含量有利于制备出符合化学计量比的NCM811薄膜。随着溅射功率的提升,NCM811薄膜的结晶度增强,材料中Ni^(2+)/Li^(+)阳离子的混排程度降低;随着衬底温度升高,薄膜由非晶逐渐转化为晶态,表面由无序非晶形貌过渡到小三角片状晶粒,厚度变薄,且更加致密。薄膜的循环性能也随着功率和衬底温度的增加有着明显的提升。结论正交试验结果表明,薄膜制备的最优工艺条件为:溅射功率110 W,衬底温度650℃,Ar∶O_(2)=2∶1(体积流量比),验证试验表明NCM811薄膜中主元素原子数占比Ni∶Co∶Mn=79.9∶10.2∶9.9,接近理想原子数占比8∶1∶1,且前50圈放电容量保持率达到72.33%。

330 kA铝电解槽异形阴极碳块对水平电流的影响

采用有限元仿真计算,对330 kA铝电解槽传统阴极碳块结构和异形阴极碳块结构的电场进行仿真模拟,主要对铝液中水平电流分布进行分析。研究发现,异形阴极碳块结构相对于传统阴极碳块结构能够在影响压降较小的前提下降低水平电流密度。模拟结果表明,在异形阴极碳块表面凸起中增加隔断并改变凸起角度,对降低铝液中水平电流效果明显,能够降低铝液中最大水平电流密度27.8%,平均水平电流密度34.3%,有效提升了铝电解槽电流效率。

Increasing(010) active plane of P2-type layered cathodes with hexagonal prism towards improved sodium-storage

Na-ion cathode materials with a fast charge and discharge behavior are needed to develop future high energy sodium-ion batteries(SIBs).However,inevitably complicated phase transitions and sluggish kinet ics during insertion and removal of Na+in P_(2)-type layered transition metal oxides generate structura instability and severe capacity decay.To get rid of such a dilemma,we report a structural optimization strategy to promote P2-type layered transition metal oxides with more(010)active planes as an efficien cathode for SIBs.As a result,as-prepared hexagonal-prism P2-type layered Na_(0.71)Ni_(0.16)Li_(0.09)Co_(0.16)Mn0.6O_(2)cathode with more(010)active planes delivers a reversible capacity of 120.1 mAh/g at 0.1 C,impressive rate capability of 52.7 m Ah/g at 10 C,and long-term cycling stability(capacity retention of 95.6%ove200 cycles).The outstanding electrochemical performance benefited from the unique hexagonal-prism with more(010)active facets,which can effectively shorten the diffusion distances of Na+,increase the Na-ion migration dynamics and nanostructural stability during cycling verified by morphology character ization,Rietveld refinement,GITT,density functional theory calculations and operando XRD.

Hierarchical porous onion-shaped LiMn204 as cathode material for lithium ion batteries

Spinel niMn2O4 is a widely utilized cathode material for Li-ion batteries. However, its applications are limited by its poor energy density and power density. Herein, a novel hierarchical porous onion-like LiMn204 （LMO） was prepared to shorten the Li diffusion pathway with the presence of uniform pores and nanosized primary particles. The growth mechanism of the porous onion-like LiMn204 was analyzed to control the morphology and the crystal structure so that it forms a polyhedral crystal structure with reduced Mn dissolution. In addition, graphene was added to the cathode （LiMn2Odgraphene） to enhance the electronic conductivity. The synthesized LiMn2O4/graphene exhibited an ultrahigh-rate performance of 110.4 rnAh.g-1 at 50 C and an outstanding energy density at a high power density maintaining 379.4 Wh.kg-1 at 25,293 W.kg-L Besides, it shows durable stability, with only 0.02% decrease in the capacity per cycle at 10 C. Furthermore, the （LiMn2O4/graphene）/graphite full-cell exhibited a high discharge capacity. This work provides a promising method for the preparation of outstanding, integrated cathodes for potential applications in lithium ion batteries.

多功能复合磁控溅射平台的应用研究

磁控溅射具有沉积温度低、薄膜致密且牢固等优点,广泛用于制备超硬膜等各种功能性薄膜,但也存在离化率和沉积速率较低、溅射平台功能较单一等缺陷,难以实现特种功能薄膜严苛的技术要求。为解决以上问题,设计了具有前后双开门、可安装多个不同类型的溅射阴极、离子源和行星工件转架可接高压脉冲偏压等的复合溅射平台,对真空镀膜室、水冷系统、整体绝缘的多工位工件转架和真空气路系统进行了优化设计,并通过理论计算、有限元分析校核了该设计的可行性。

全固态薄膜锂电池研究进展和产业化展望

全固态薄膜锂电池利用固态电解质替代传统电解液,采用多层薄膜堆垛的平面结构,属于新一代的锂离子电池,在军民两用的可穿戴设备、便携式移动电源、汽车和航空动力电池等领域应用前景广阔。该类电池因高安全性、长循环寿命、高比容量和高能量密度等优势性能受到业界广泛关注。本文概述薄膜锂电池的分类和充放电原理,总结正负极、电解质薄膜材料的发展历程和薄膜制备手段的改进,对比各类电池材料的电化学性能,引入该方向最新的研究进展:三维薄膜锂电池,可变形的柔性电池,高电压、大容量电池组。汇总国外商用电池产品、关键优势技术、电池制备设备,提出薄膜锂电池亟待解决的科学问题和国内潜在的产业化方向。