锂离子电池锡氧化物负极材料的研究进展

锡基氧化物以其高的理论比容量、低成本、低毒性、宽广的实用性成为理想的锂离子电池负极材料,然而在其充放电过程中体积变化较大,影响了电极的循环性能.从锡基氧化物的储锂机理、制备方法和改善锡基氧化物电化学性能的研究等方面,分析总结了近年来锡基氧化物负极材料在结构和形貌、掺杂、制备锡基氧化物复合材料方面的最新进展,展望了其发展...     

锂离子电池负极材料的研究进展

综述了锂离子电池负极材料的研究进展,介绍了碳素材料、锡氧化物和锡基复合氧化物负极材料。指出今后负极材料的研究与开发重点将朝着高比容量、高充放电效率、高循环性能以及低成本方向发展。     

高可逆比容量锡负极循环性能的改善

为了改善锂离子蓄电池中高比容量锡负极的循环性能 ,采用多孔结构、高比表面积的多孔碳材料为载体制备得到Sn/PC复合材料。电化学测试表明 :用该类复合材料制备的电极表现出良好的锂嵌脱能力 ,循环性能比锡类电极有显著提高 ,其循环性能和可逆比容量与复合电极中锡的含量密切相关。第二次循环后复合电极充放电效率接近 10 0 % ,具备较好的充放电倍率特性和较低的嵌、脱锂电位。制备出的复合材料能防止锡嵌、脱锂过程产生的严重体积效应 ,从而提高电极循环性能 ,为锂离子蓄电池中合金类高比容量负极材料的实用提供了崭新的思路     

锂离子电池锡薄膜负极材料研究现状

从理论计算和制备技术两个方面综述了锂离子电池锡薄膜负极材料的研究进展.概述了基于密度泛函理论(DFT)的第一性原理平面波赝势方法,简述了该方法在预测电极材料电化学性能中的运用.综合介绍并比较了溅射、电化学沉积和机械球磨等几种薄膜制备方法的优缺点.指出了锡薄膜负极材料存在的问题及发展前景.     

纳米锡铁复合氧化物的制备与电化学性能

采用沉淀法制备了作为锂离子电池负极材料的纳米锡铁复合氧化物粉末,并用X射线衍射(XRD)对其结构进行了分析,用透射电镜(SEM)对其形貌进行了表征,对其充放电和循环性能等电化学性能进行了测试.结果表明,采用沉淀法可以制备出颗粒粒度分布较集中,尺寸为20 nm的锡铁复合氧化物;充放电过程中从20～50周,锡铁复合氧化物放电比容量由285,6 mAh/g衰减到279.1 mAh/g,放电容量保持率较高(98％),说明纳米锡铁复合氧化物具有较高的放电比容量和良好的循环性能.     

溅射功率对Sb薄膜负极材料循环性能的影响

采用射频磁控溅射法分别在100、200、300 W和400 W功率下制备了4种锂离子电池用Sb薄膜负极材料.通过X射线衍射光谱法(XRD)、扫描电子显微镜法(SEM)、电感耦合等离子体光谱分析法(ICP)、恒电流充放电对4种薄膜材料的结构、形貌及循环性能等进行了表征.实验结果表明,随着溅射功率增加,Sb薄膜晶化程度加剧,结晶趋于完整,颗粒粗化.在相同溅射时间30 min的情况下,当功率为300 W时,获得的Sb薄膜电极具有最好的循环性能,首次嵌锂比容量达640 mAh/g,20次循环后比容量维持在323 mAh/g,容量保持率为51%.     

溅射功率对Sn薄膜负极材料循环性能的影响

采用磁控溅射法分别在150、250、400 W功率下制备了3种锂离子电池用Sn薄膜负极材料.通过X射线衍射光谱法(XRD)、扫描电子显微镜法(SEM)、恒电流充放电对3种薄膜材料的结构、形貌及循环性能进行了表征.实验结果表明,随着溅射功率增加,薄膜的非晶成分减少,晶化加剧,颗粒粗化.在相同溅射时间20 min的情况下.当溅射功率为250 W时,获得的Sn薄膜电极具有最好的循环性能,首次嵌锂容量为653.8 mAh/g,30次循环后容量维持在515mAh/g.容量保持率达79%.     

Sn-Al合金作为锂电池负极材料的掺Ni改性研究

采用磁控溅射的方法,制备了SnAl/Ni双层结构薄膜负极材料,通过XRD检测样品的物相结构,并通过组装半电池测试材料的循环稳定性。XRD结果表明:制备所得的双层结构薄膜样品主要为Ni3Sn2与Cu40.5Sn11的固溶相,不同溅射功率下样品的结晶化程度也不一样。循环性能测试结果表明:Ni溅射功率为100W的样品50次循环后充放电比容量维持在500mAh/g左右,具有较好的循环性能。掺Ni后形成的Sn-Ni-Al负极材料的循环稳定性与结晶化程度有关,结晶化程度越差的样品,由于结晶的不规则性,引入更多的嵌锂间隙位置,便于锂离子的进出,获得越好的循环性能。其次对于Sn-Ni-Al负极,多个二元相固溶时,由于非活性物质对循环时的体积变化具有一定的缓解作用,多个二元相作用叠加,导致循环稳定性优于三元合金相。在合成多元合金负极时,非晶化及多个二元相的固溶都是有利于循环稳定性提高的方法之一。本文为Sn基合金负极的改性研究提供了一个新的手段。     

锂离子电池锡基负极材料的研究进展

总结了锡氧化物、锡复合氧化物以及锡合金的制备方法、性能和贮锂机理,概述了锂离子电池锡基负极材料的研究现状.锡基负极材料的结构与性能因其制备方法的不同而有差异,但贮锂机理都倾向于合金机理.     

硬炭用于锂离子电容器的研究及其低温性能

以硬炭为研究对象,考察了不同预嵌锂量硬炭负极对锂离子电容器电化学性能的影响,通过充放电性能测试,分析了常温充放电、倍率性能、循环性能、比能量、比功率、常温充电低温放电以及低温充放电性能,研究结果表明,当负极预嵌锂量截止比容量为300 m Ah/g时,由于提供了稳定的电位和足够的锂离子,锂离子电容器综合电化学性能最佳。     

氮离子束能量对光伏新材料氮化碳薄膜的影响

将碳基材料应用于太阳电池半导体器件的研究已经在国内外得到重视和开展。采用离子束溅射反应沉积技术,在p型绒面硅和p型硅基片上沉积出用于制备太阳电池的氮化碳薄膜(a-C:N)。ID/IG比率,ISi/IG比率是研究氮化碳薄膜微结构的重要拉曼参数,对这些参数随氮离子束能量的变化进行了研究。能量散射光谱(EDS)和透射电子显微镜(TEM)测试显示随氮离子束能量增大,薄膜中氮原子含量下降,团簇尺寸大幅下降,非晶网络中团簇分布也趋于均匀。用真空热蒸镀工艺在氮化碳/硅异质结的氮化碳薄膜表面镀上一层半透明的铝薄膜,测得AM1.5标准光照下的开路电压随氮离子束能量的增加而增大。     

Study on the electrical and optical properties of ITO and AZO thin film by oxygen gas flow rate

Transparent conductive oxide (TCO) thin films such as tin doped indium oxide (ITO), zinc doped indium oxide (IZO) and Al doped zinc oxide (AZO) have been widely used as transparent electrode for display. ITO and AZO thin films for display was prepared by the facing targets sputtering (FTS) system. The FTS method is called a plasma-free sputter method because the substrate is located apart from plasma. This system can deposit the thin film with low bombardment by high energetic particles in plasma such as γ-electrons, negative ions and reflected Ar atoms. ITO and AZO thin films were deposited on glass substrate at room temperature with oxygen gas flow rate and input power. And the electrical, structural and optical properties of the thin films were investigated. As a result, the resistivity of ITO, AZO thin film is 6?×?10^?4 Ω cm, 1?×?10^?3 Ω cm, respectively. And the optical transmittance of as-deposited thin films is over 80% at visible range.     

薄膜锂电池的研究进展

微电子机械系统(MEMS)和超大规模集成电路(VLSI)技术的发展对能源的微型化、集成化提出了越来越高的要求。全固态薄膜锂电池因其良好的集成兼容性和电化学性能成为MEMS和VLSI能源微型化、集成化的最佳选择。简单介绍了薄膜锂电池的构造,举例说明了薄膜锂电池的工作原理。从阴极膜、固体电解质膜、阳极膜三个方面概述了近年来薄膜锂电池关键材料的研究进展。阴极膜方面LiCoO2依旧是研究的热点,此外对LiNiO2、LiMn2O4、LiNixCo1-xO2、V2O5也有较多的研究;固体电解质膜方面以对LiPON膜的研究为主;阳极膜方面以对锂金属替代物的研究为主,比如锡的氮化物、氧化物以及非晶硅膜,研究多集中在循环效能的提高。在薄膜锂电池结构方面,三维结构将是今后研究的一个重要方向。     

High Quality Silicon-Based AlN Thin Films for MEMS Application

ABSTRACT

Aluminum nitride is an attractive piezoelectric material for MEMS devices such as bulk acoustic wave (BAW) devices. (002)-oriented AlN films were deposited on Si, Al and Pt by reactive sputtering. Optimized AlN (002) peak reaches a full width at half maximum (FWHM) of 5.6°. Auger electron spectroscopy is used to analyze the oxygen contamination of films. To find the suitable electrode material for device application, the growth mechanism of AlN crystallites on different substrates is also discussed. Based on sputtered AlN films, the prototype of AlN thin film bulk acoustic resonator (TFBAR) was fabricated successfully.     

磁控溅射镍膜及其性能的研究

采用磁控溅射法在聚对苯二甲酸乙二醇酯(PET)基材上制备了镍薄膜。用扫描电子显微镜(SEM)分析溅射功率、溅射真空室气压等工艺参数对镍薄膜表面形貌的影响;研究了溅射工艺参数与薄膜性能之间的关系。实验结果表明,在室温下,随着溅射气压的增加,沉积速率和粒径都是先增加后又逐渐变小,而薄膜的电阻则随着压强的增大先减小后逐步增大;薄膜的表面粗糙度随着溅射功率的增加而增大;膜层与基材的剥离强度较大且均匀,膜层结合较为牢固,薄膜的耐摩擦性能较为优良。     

Structural and electrochemical properties of Nichrome anode thin films for lithium battery

Low cost anode materials having a high electrochemical efficiency have been critical in the success of thin film batteries that are applicable in ubiquitous environments as a portable energy source. Nichrome thin films are ideally suited for use in hybrid assemblies but their applications include precision integrated circuits in fields of telecommunications, instrumentation, power supplies, military and medical equipment where low noise and good power dissipation are required. With such a wide spectrum of applications, it is important to understand the electric behavior of the Nichrome alloy thin films by their microstructure. In this work, nanocrystalline films of nickel chromium alloys were deposited on alumina substrate by radio frequency (RF) magnetron sputtering technology. High purity nickel and chromium sputtering target were used for the deposition. First, aluminum was deposited on ceramic substrate acts as a current collector and over that NiCr was deposited by RF sputtering method. Both the layers were analyzed for structural and electrical properties using X-ray diffraction (XRD), energy dispersive X-ray analysis (EDS), atomic force microscopy (AFM), scanning electron microscopy (SEM) and cyclic voltammetry. The XRD peak confirms that deposited NiCr and Aluminum have tetragonal and cubic structures, respectively. The crystallite size was determined by full width at half maximum of XRD peaks. Structure, composition and the properties of the film are the major focus of this paper. Composition ratio between nickel and chrome obtained by EDS is 1:1. Particle size and microstructure of the film have been studied by SEM and AFM. Electrochemical properties of the films were analyzed. Reaction mechanism for the insertion and excretion is reported. After Lithium insertion and extraction the effect on the surface and structure of the thin film has been studied. The composition of equilibrium phases of NiCr as useful as attracting anode for the thin film battery. Nichrome on aluminum thin films as an anode has been attracted because it provides practical advantages including low cost production and competitive electrical performance.     

Integration of Piezoelectric PZT Thin Films with Internal Electrodes into an Actuator Structure for MEMS Applications

This paper presents the Finite-Element-Method (FEM) analyses, the processing, and the characterization of micro cantilever beams, which are driven by the transversal piezoelectric effect of two PbZr 0.45 Ti 0.55 O 3 (PZT) thin films with an internal platinum electrode. SiO 2 /Si 3 N 4 is used as elastic substrate for this stack. For the development of this thin film bimorph silicon bulk micro machining is used in combination with chemical solution deposition (CSD), sputter technology and reactive ion etching (RIE). For electrical and piezoelectric characterization of the PZT films CV-, hysteretic, and double beam laser interferometer measurements are carried out. The findings are compared to the FEM analyses and the results of a single piezoelectric layer design [1].     

光学薄膜制备用的多离子束电子束系统

本文介绍一种新型的光学薄膜制备用多离子束电子束系统。     

PECVD低功率沉积氮化硅薄膜研究

为了减少太阳能电池氮化硅薄膜生产工艺中的缺陷、提高太阳能电池的转换效率,采用等离子增强化学气相沉积法在射频功率较低的条件下,对N型单晶硅片表面进行氮化硅沉积,获得与高射频功率沉积时相同膜厚和折射率的氮化硅膜,通过试验分析了低功率沉积工艺对电池电参数、对膜厚均匀性的影响。结果表明,在低功率沉积工艺条件下,有助于改善膜厚均匀性,使膜厚不均匀度由12%下降到6%,太阳能电池转换效率提高了0.05个百分点。     

氧化物薄膜抑制量子点的光衰性能

量子点应用于LED中,可获得高饱和性、宽色域光源,在液晶显示背光源领域前景广阔。但是,影响量子点寿命的因素很多,如温度、水氧等,严重阻碍了其推广应用。目前,水氧对量子点光衰性能影响的研究较少,本文旨在研究无机氧化物薄膜阻隔层对量子点光衰性能的影响。量子点成膜后表面溅射Al2O3、SiO2水氧隔离薄膜,蓝光LED激发绿光量子点,研究其光衰性能。结果表明,与无隔离膜的样品相比,单层SiO2薄膜的样品光衰性能有所改善;双层的SiO2薄膜及SiO2/Al2O3复合薄膜,可以有效地减小薄膜孔洞大小和孔洞密度,阻隔水氧的进入,抑制量子点的光衰减,提高量子点寿命。