钛基材料的制备及其在锂离子电池中的应用研究

发布时间：2018-03-19 10:05

本文选题：锂离子电池　切入点：3D网状结构　出处：《昆明理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着能源需求的日益增长和环境污染的日益加剧,能源的开发利用受到研究者们越来越多的关注。在此背景下,寻找高效、安全、环境友好的储能装置成为能源领域的重要研究课题。锂离子电池因其比容量高、绿色环保及携带方便等优点,成为电化学储能装置领域的研究热点。TiO2作为锂离子电池负极材料,在嵌脱锂过程中具有体积应变小(约3%),可有效避免锂枝晶的生长等优点,使其在安全性高、循环寿命长的储能电池领域具有广阔的应用前景。然而,该材料固有的低电子电导率和较低的实际比容量使其电化学活性不能得到很好地发挥。本论文首先通过水热法制备得到TiO2柔性电极材料。该材料在400 mA/g的电流密度下循环300圈之后,依然具有107.0 mAh/g的放电比容量,容量保持率为62.2%。该材料具有3D网状结构,有利于作为其他材料的载体,制备得到复合材料,实现优势互补。为使TiO2柔性电极材料得到更广泛的应用,本论文对MoS2@TiO2材料和SnO2@TiO2材料的制备进行了研究。通过水热法制备得到的MoS2@TiO2材料拥有较高的放电比容量和较好的循环稳定性,经过高温煅烧,提高了 TiO2与MoS2的结合力,表现出更加优异的电化学性能。二次煅烧过的MoS2@TiO2材料在800 mA/g的电流密度下循环300圈之后,依然具有361.5 mAh/g的放电比容量,容量保持率为88%。在TiO2柔性电极材料上刷4遍SnCl4溶液时,通过煅烧法可以制备得到电化学性能最佳的SnO2@TiO2复合电极材料。该材料在400 mA/g的电流密度下循环100圈之后,依然具有449.4 mAh/g的放电比容量,容量保持率为74.2%。
[Abstract]:With the increasing demand for energy and increasing environmental pollution, researchers pay more and more attention to the development and utilization of energy. Environmentally friendly energy storage devices have become an important research topic in the field of energy. Because of their high specific capacity, green environment and easy to carry, lithium ion batteries have become the research hotspot in the field of electrochemical energy storage devices. TiO2 is used as negative electrode materials for lithium ion batteries. In the process of intercalation of lithium with small volume strain (about 3%), it can effectively avoid the growth of lithium dendrite, and make it have a wide application prospect in the field of high safety and long cycle life energy storage battery. Because of its low electronic conductivity and low specific capacity, the electrochemical activity of the material is not well developed. In this paper, the TiO2 flexible electrode material was prepared by hydrothermal method. The current density of the material is 400 mA/g. After 300 cycles, The material still has a specific discharge capacity of 107.0 mAh/g, and the capacity retention is 62.2%. The material has a 3D mesh structure, which is beneficial to the preparation of composites as a carrier of other materials. In order to make TiO2 flexible electrode materials more widely used, In this paper, the preparation of MoS2@TiO2 and SnO2@TiO2 materials is studied. The MoS2@TiO2 materials prepared by hydrothermal method have higher discharge specific capacity and better cycle stability. After high temperature calcination, the binding force between TiO2 and MoS2 is improved. The second calcined MoS2@TiO2 material has a discharge specific capacity of 361.5 mAh/g and a capacity retention rate of 88% after circulating at a current density of 800 mA/g for 300 laps. After brushing four times of SnCl4 solution on the TiO2 flexible electrode material, the second calcined MoS2@TiO2 material has a specific discharge capacity of 361.5 mAh/g. The SnO2@TiO2 composite electrode material with the best electrochemical performance can be prepared by calcination method. The material still has a specific discharge capacity of 449.4 mAh/g and a capacity retention rate of 74.2% after a current density of 400 mA/g.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB332;TM912

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