Electrodeposition,Structure and Lithium Storage Performance of Novel Sn-Co-Zn(P) Alloy Electrode for Lithium Batteries

随着信息化技术和便携式电子设备的快速发展，对二次能源提出了更高的要求，其中锂离子电池是最重要的二次能源之一。锡基合金具有高的质量比容量和体积比容量，是下一代锂离子电池负极材料的研究热点之一。其主要缺陷在于嵌锂过程中巨大的体积膨胀而导致的活性材料的粉化脱落，循环性能不好。目前解决的主要方法有：①制成纳米材料；②与活性或非活性元素合金化；③用活性或非活性材料包覆。此外集流体的表面形貌各多孔对电极性能的提高也起着关键性的作用。根据以上构想，本文展开了以下几个方面的研究： （1）利用电沉积的方法在Sn-Co二元合金体系中引入第三种活性元素锌和第四种活性元素磷。通过线性扫描实验及循环伏安实验对Sn-C...With the information technology and the portable electronic equipment rapid development, lithium ion batteries must have high specific capacity. Tin -based alloys have been suggested as promising alternative anode materials for their high gravitational and volumetric capacity. The main disadvantage of tin and tin-based alloys is large volume expansion, which causes poor cycleablity. Up to now, the...学位：理学硕士院系专业：化学化工学院化学系_物理化学(含化学物理)学号：2052006115195

Electrodeposition and Electrochemical Properties of Ternary Sn-Co-Zn Alloy Electrodes as Anodes for Lithium-Ion Batteries

Corresponding author. Email: [email protected]; Tel: +86-592-5343629.[中文文摘]运用电沉积技术制备出Sn-Co-Zn合金电极材料.采用X射线衍射(XRD)和扫描电子显微镜(SEM)分析了该合金材料的相结构和表面形貌.通过循环伏安和电位阶跃实验研究了Sn-Co-Zn合金的电沉积机理,实验表明,Sn-Co-Zn合金电沉积按扩散控制连续成核和三维生长方式进行.XRD结果表明,该合金由CoSn3、Co3Sn2和Zn组成.电化学性能测试表明:Sn-Co-Zn合金电极首次放电(脱锂)容量达751mAh·g-1,首次循环的库仑效率为88%;30周循环之后放电容量为510mAh·g-1.该Sn-Co-Zn合金电极良好的电化学储锂性能可能归因于材料的多相结构.[英文文摘]A ternary Sn-Co-Zn alloy film was successfully prepared by electrodepositi on copper foil. Electrochemical deposition of the Sn-Co-Zn alloy was studied by cyclic voltammetry (CV) and chronoamperometry (CA). The structure and electrochemical performance of the electroplated Sn-Co-Zn alloy electrodes were also investigated in detail. The CV and CA results revealed that the initial deposition kinetics of the Sn-Co-Zn alloy corresponds to a model that includes a three-dimensional progressive nucleation and diffusion controlled growth. XRD results showed that the electrodeposited Sn-Co-Zn alloy consists of CoSn3, Co3Sn2, and Zn phase. Electrochemical tests indicated that at the first cycle, the discharge capacity (desertion) and columbic efficiency are measured 751 mAh·g-1 and 88%, respectively, at the 30th cycle, the Sn-Co-Zn alloy electrodes still delivered a discharge capacity of 510 mAh·g-1. The good lithium storage performance of the Sn-Co-Zn electrode is ascribed to multi-phase structure of the electrode.国家自然科学基金(20773102);国家基础研究重大项目计划(973)(2009CB220102)资

Preparation and performance of Sn-Co-Zn nanorods array alloy electrode

采用液相法制备铜纳米棒阵列,并用作锂离子电池负极集流体,通过电沉积制备Sn-CO-zn纳米棒阵列合金电极。合金电极主要是由CO Sn、CO Sn2和单质zn组成的混晶。以1 C在0.02~1.50 V循环,合金电极首次循环的放电比容量为813.8 M AH/g,库仑效率为87.5%,第50次循环的放电比容量为467.0 M AH/g。电极活性材料多相结构及纳米阵列间隙,可缓解嵌锂过程中的体积膨胀。Copper nanorods array was prepared by liquid phase reaction and used as anode current collector material for Li-ion battery.Sn-Co-Zn nanorods array alloy electrode was prepared by electrodeposition.The alloy electrode was the mixed crystal mainly composed of CoSn,CoSn2 and Zn.When cycled in 0.02 ~ 1.50 V with 1 C,the specific discharge capacity of alloy electrode in initial cycle was 813.8 m Ah / g,the columbic efficiency was 87.5%,the specific discharge capacity in 50 th cycle was 467.0 m Ah / g.The multi-phase structure of electrode material and the nanorods array could alleviate the volume expansion during lithium intercalation

Image Reconstruction Functions and Metal Pin Artifact Reducer in CT-Scanner

It is well known that metallic materials in patients cause severe artifacts on CT scans, which can considerably impair the information contained in the image. As the CT scanner prepares the user\u27s program, we used the soft Metal Pin Artifacts Reducer (MPAR) program, and attempted to apply the CT to the removal of artifacts which were brought about due to the use of dental materials or metals. Preceding the use of this program, image reconstruction functions (FC) of the CT scanner vary from FC1 to FC7, so we investigated the relation between each function from FC1 to FC5 and resultant images. CT images for FC1, FC2 and FC4 were considerably softer images, and artifacts originated in heavy metals were more intense at FC1 and FC2. However, among those tested, FC1 was harder and FC4 was softer than FC2. Images for FC3 and FC5, on the other hand, were vary hard. Results obtained by measuring CT values of dental materials indicated that the rates of function for FC1 to FC5 were approximately constituted by 1.0:0.9:0.3:0.8:0.3. Therefore, it seems that the softening of image from FC1 to FC2, and as far as FC4, is due to a lower rate of function; allowing for the production of a lower image contrast by decreasing the differences of CT value between an object and neighbors. FC3 and FC5 image hardness, on the other hand, was due to condensing CT values to 1/3 of FC1. Consequently, the images of FC3 and FC5 could not be clearly discerned and appeared rather flat and sharp. Finally, we examined the removal of artifacts by using MPAR soft. In most cases, artifacts were not successfully removed during the first procedure; barely visible white remnants were left in place of the artifacts. Regardless of whether remnants could be seen or not, a broad banded image always appeared in their place. Therefore, from these results, we currently feel that instead of immediately utilizing MPAR soft to reduce artifacts, it is better to select desirable window levels and widths which cannot be disturbed by artifacts, and can be made to fit to the diagnostic purpose. In order to more clearly understand the results of the removal of artifacts in the dental region, we feel that more time will be needed. It is our hope that serious consideration continues to be given to the development of soft programs

The Three Dimentional Reconstruction of CT Images for the Maxillo-Facial Lesions

Three-dimensional reconstruction of CT images has been actively pursued in recent years. In Japan, soft ware has been developed for 3-D image reconstruction and, as a result, several reports have also been done. We have used 3-D soft ware incorporated into CT scanner at MDC since 1988. This soft ware had originally been developed by Toshiba Medical Co. as a part of the image processing system for the TCT-60A-EX and TCT-700S (CT scanner, Toshiba). It performs with easy handling, 3-D image reconstruction in a short time. The shading, lighting, and viewing direction of 3-D images and set at will. Moreover, 3D-distance, angle and volume are measurable on the 3-D images. We will report here the outline of the procedure and the optimal conditions for image processing, we will also show some clinical cases

Ultrasound Imaging in Oral Radiology

The fundamentals, reseach method, principles and structure of ultrasound imageapparatus ; normal ultrasound image for oral maxillofacial surgery, and the signature of basic ultrasound have been described. The areas of research revolved around disorders that occur in the soft tissue of the jaw and facial region and diseases that affect the salivary glands. Especially in the case of salivary gland diseases, ultrasound imaging can obtain information that x-ray examination can\u27t without exposing the patient to radiation.Furthermore, unlike other methods, it is a non-surgical process. Ultrasound imaging is different from x-ray images. However, the image dose have an artifact that appears on the film. Therefore, the form and the place in which this artifact appears must be more thoroughly researched and understood before ultrasound imaging is carried out. Ultrasonography provides much more information that the other types of examinations can achieve. To obtain such precise imaging information anatomical knowledge, better skills in carrying out this method and new devices are needed. It is hoped that in the future other methods can be implemented along with x-rays

A Desk-Top Image Archiving/Processing Workstation for Oral Radiology and Color Images

The Department of Dental Radiology of Matsumoto Dental College is presently in the process of a new type of compact image archiving/processing system. The system consists of a personal computer, an image scanner with transparent unit for film scanning, an off-line CT image archiving through a floppy disk reader, a precision image display with full-color, a video printer and a high density 3.5 inch magneto-optical disk system. The system supports various image processing abilities which including frequency domain analysis and color processing. Our emphasis is on quality over speed and operation has also been tested and approved by dental radiologists and by the commercial availability of a system capable of an acceptable performance