新型锂硫电池正极材料的研究

发布时间：2018-06-22 05:29

本文选题：锂硫电池 + 聚苯胺　；参考：《长春理工大学》2017年硕士论文

【摘要】：单质硫价格低廉,储量丰富,理论比容量较高,现被广泛用作锂硫电池正极研究。但单质硫及其放电终产物为绝缘体,且充放电过程中产生的多硫化物向电解液扩散引起的穿梭效应影响电池性能。本论文将导电聚苯胺与单质硫复合,在改善其导电性的同时利用吸附作用抑制多硫化物的穿梭效应。本论文在水-乙醇的液相体系中制备了硫酸、醋酸、硝酸掺杂的聚苯胺-硫-碳复合材料,研究不同酸掺杂的聚苯胺对电池性能的影响。通过电池测试发现,三种复合材料的循环性能具有差异,借助量子化学计算结合能,经不同质子酸掺杂的导电聚苯胺对多硫化物的吸附强度不同。利用一种与多硫化物具有高结合位点和高结合能的聚苯胺的质子酸掺杂剂—酸性磷酸酯,制得层层包裹的聚苯胺-硫-碳复合纳米材料。该材料具有较好的电池性能:0.5C的倍率下,第一圈放电比容量为1283 mAh/g,充放电循环100圈后比容量保持率为86.4%。
[Abstract]:Because of its low price, abundant reserves and high theoretical specific capacity, it is widely used in the research of lithium sulfur batteries. However, simple sulfur and its discharge end product are insulators, and the shuttle effect caused by the diffusion of polysulfide into electrolyte during charge and discharge affects the performance of the battery. In this paper, the conductive Polyaniline is combined with simple sulfur to improve its conductivity and to suppress the shuttle effect of polysulfide by adsorption at the same time. In this paper, Polyaniline-sulfur-carbon composites doped with sulfuric acid, acetic acid and nitric acid were prepared in water-ethanol liquid system. The effect of different acid-doped Polyaniline on the performance of the battery was studied It was found that the cyclic properties of the three composites were different. By means of quantum chemistry calculation of binding energy, the adsorption strength of polysulfide was different with different protonic acid doped conductive Polyaniline. Polyaniline-sulfur / carbon nanocomposite nanomaterials were prepared by using a proton acid dopant acid phosphate ester with high binding site and high binding energy to polysulfide. The specific discharge capacity of the first cycle is 1283 mg / g, and the specific capacity retention is 86.4 after 100 cycles of charge / discharge cycle.
【学位授予单位】：长春理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB33;TM912

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