碳复合锑基、硫基电极材料的合成及其电化学性能的研究

发布时间：2018-03-23 08:51

本文选题：锑　切入点：硫　出处：《中国科学技术大学》2017年硕士论文　论文类型：学位论文

【摘要】：碳材料与纳米材料的复合是提高锂离子和钠离子电池电极材料电化学性能的主要方法。在本论文中,分别合成了碳复合锑(Sb)负极材料和碳复合硫(S)正极材料,并并研究了其中碳的引入对电池电化学性能的影响,本论文的主要主要创新点如下:1.发展了锑/碳(Sb/NPC)复合电极材料的制备方法。首先采用水热法制备了一维的氨三乙酸镍(Ni-NTA)配合物前体,再将其在Ar气保护下,热分解得到嵌有镍(Ni)金属颗粒的氮掺杂的一维碳复合材料,随后通过纳米限域的置换法,与SbCl3反应生成负载Sb纳米颗粒的一维N掺杂多孔结构的锑碳复合物(记为Sb/NPC),其中金属颗粒的尺寸约为10-20 nm。将此Sb/NPC复合材料作为负极材料时,在锂离子电池中,在200 mA/g电流下,循环100圈后,可逆容量为556 mAh/g。在钠离子电池中,100 mA/g电流下,循环100圈,容量为400.9 mAh/g。与之前文献报导的类似材料相比,该复合材料的电化学性能得到提升。该材料性能的提升,主要是由于这种独特的纳米构筑:氮掺杂,一维,多孔,纳米化的锑颗粒,该材料具有良好的结构稳定性,可以有效的缓解Sb电极材料在锂离子嵌入脱出的过程中的体积膨胀问题。2.发展了硫/碳(S/NPC-Cu)复合电极材料的制备方法。首先采用乙二胺四乙酸(EDTA),三聚氰胺为碳源和氮源,硝酸铜为金属源,通过高温热解发制备了均匀负载金属铜(Cu)的氮掺杂的多孔碳纳米片,再将其与单质硫粉通过真空加热复合,制备了硫/硫化铜/碳(记为S/NPC-Cu)和S/NPC碳纳米复合材料,作为锂硫电池的正极材料,在0.5C(1C = 1675 mAh/g)倍率下,循环200圈,容量分别为701 mAh/g和588 mAh/g,与纯硫正极材料相比,复合材料电极的电池循环性能得到很大提升。电池性能的提升应当归因于:1.氮掺杂提高了材料的导电率及与多硫化物的吸附作用,2.金属硫化物进一步提供了较多的活性位点供多硫化物吸附。
[Abstract]:The composite of carbon materials and nano-materials is the main method to improve the electrochemical performance of electrode materials for lithium ion and sodium ion batteries. In this paper, carbon composite antimony ion (SB) negative electrode materials and carbon compound sulfur ion (S) cathode materials are synthesized, respectively. The influence of carbon on the electrochemical performance of the battery was also studied. The main innovations of this thesis are as follows: 1. The preparation method of SB / C Sb / NPC composite electrode material has been developed. Firstly, the precursor of 1-D Ni-NTA-aminotriacetate complex was prepared by hydrothermal method, and then the precursor was prepared under the protection of ar gas. A nitrogen-doped one-dimensional carbon composite containing Ni (Ni) particles was obtained by thermal decomposition. One-dimensional N-doped antimony carbon composites supported on SB nanoparticles were formed by reacting with SbCl3 (referred to as SB / NPCs, where the size of the metal particles is about 10-20 nm). When the Sb/NPC composite is used as a negative electrode material, in the lithium ion battery, at 200 mA/g current, After the 100th cycle, the reversible capacity is 556mAh/ g. At 100 mA/g current in the sodium ion battery, the capacity is 400.9 mAh/ g. The electrochemical properties of the composite are improved compared with the similar materials reported in previous literatures. Mainly due to this unique nanomaterials: nitrogen-doped, one-dimensional, porous, nanocrystalline antimony particles, the material has good structural stability, It can effectively alleviate the volume expansion of SB electrode materials in the process of lithium ion intercalation. 2. The preparation method of S / C Si / NPC-Cu) composite electrode materials has been developed. Firstly, EDTAA was used as ethylenediamine tetraacetate and melamine as carbon and nitrogen source. Copper nitrate as a metal source, N-doped porous carbon nanochips were prepared by pyrolysis at high temperature, and then combined with elemental sulfur powder by vacuum heating. Sulfur / copper sulphide / carbon (S / NPC-Cu) and S/NPC carbon nanocomposites were prepared, which were used as cathode materials for lithium-sulfur batteries at a 0.5C(1C = 1675 mAh/ g ratio, with a cycle capacity of 701 mAh/g and 588mAhP / g, respectively, compared with pure sulfur cathode materials. The battery cycle performance of composite electrode has been greatly improved. The improvement of battery performance should be attributed to: 1. Nitrogen doping improves the conductivity of the material and its adsorption with polysulfide. 2. Metal sulfides provide more. The active sites are used for polysulfide adsorption.
【学位授予单位】：中国科学技术大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O646;TB33

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