新颖结构碳球的可控制备及其在锂硫电池中的应用

发布时间：2018-06-12 05:58

本文选题：刺状二氧化硅球 + 花型结构碳纳米球　；参考：《温州大学》2017年硕士论文

【摘要】：采用刺状二氧化硅球作为模板,水热可控制备构建新颖三维花型结构碳纳米球作为硫宿主材料,担载硫应用于锂硫电池正极。基于其高比表面积、大孔容以及互通介孔通道的结构特点,增加硫装载量、抑制多硫化物溶解、利于电解液离子扩散和迁移,以期改善电池性能。详细探究宿主碳材料的结构对锂硫电池性能影响,揭示构效关系。具体内容如下:(1)采用水热法合成刺状二氧化硅纳米球,探究影响二氧化硅纳米球尺寸、形貌的关键因素,实现制备的可控性,并提出不同尺寸二氧化硅球形成的可能机理。(2)以刺状二氧化硅纳米球为模板,葡萄糖为碳源,水热法合成花型结构碳纳米球。通过控制碳源和模板的投料比、碳化温度、碳化气氛等实现对碳纳米球的形貌、结构调控。探究不同结构碳纳米球、担载硫含量等因素对锂硫电池容量、倍率性能以及循环稳定性的影响,结合碳材料对多硫离子吸附、循环前后材料结构和电解液的分析,揭示碳材料结构与性能之间的关系。(3)以刺状二氧化硅纳米球为模板,以壳聚糖为碳源和氮源,水热法合成花型结构氮掺杂碳纳米球。研究不同碳化温度、碳源和模板的投料比对碳材料结构的影响,并进一步探究不同结构硫宿主碳材料对锂硫电池性能的影响。另外,我们拓展该类花型结构氮掺杂碳纳米球在电催化氧还原中的应用,详细研究碳材料比表面积和氮掺杂含量对电催化氧还原性能的影响。
[Abstract]:Using spiny silica ball as a template, water and heat can be controlled to construct a novel three-dimensional flower type carbon nanosphere as a sulfur host material. The load of sulfur should be used as the cathode of lithium sulfur battery. Based on its high specific surface area, large pore volume and the structure characteristics of interconnected mesoporous channels, the amount of sulfur loading can be increased, the dissolution of polysulfide is inhibited and the electrolyte ion is favorable. Diffusion and migration in order to improve the performance of the battery. The influence of the structure of the host carbon material on the performance of the lithium sulfur battery is detailed. The specific contents are as follows: (1) the key factors affecting the size and morphology of the silica nanospheres are investigated by the hydrothermal method, and the controllability of the preparation is realized. The possible mechanism of the formation of SiO2 spheres. (2) the morphology and structure of carbon nanospheres are controlled by controlling the feeding ratio of the carbon source and the template, the temperature of the carbonization and the carbonization atmosphere, and the different structure carbon nanospheres and the carrying sulfur are carried out by the template of the spiny silica nanosphere and the glucose as the carbon source. The influence of content and other factors on the capacity, ratio performance and cyclic stability of lithium sulfur batteries, the relationship between structure and properties of carbon materials was revealed by the adsorption of polysulfide ions and the analysis of the structure and electrolyte of carbon materials before and after the cycle. (3) the preparation of chitosan as a template and chitosan as carbon source and nitrogen source, and hydrothermal synthesis of chitosan as a carbon source and nitrogen source. The effects of different carbonization temperatures, carbon sources and templates on the structure of carbon materials were investigated, and the effects of carbon materials on the properties of lithium sulfur batteries were further investigated. In addition, the application of this type of flower type nitrogen doped carbon nanospheres in the electrocatalytic oxygen reduction was studied in detail. The influence of specific surface area and nitrogen doping content of carbon materials on the performance of electrocatalytic reduction of oxygen.
【学位授予单位】：温州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ127.11;TM912

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