锂离子电池硅基负极材料的改性研究

发布时间：2018-06-07 23:29

本文选题：锂离子电池 + 纳米硅　；参考：《哈尔滨工业大学》2014年硕士论文

【摘要】：本文通过对纳米硅进行表面改性，，以改善其循环稳定性与循环效率，从而提高其电化学性能。本文首先研究了化学镀铜改性纳米硅，以及高电导率掺杂态导电聚苯胺的制备，并采用原位聚合法制备了聚苯胺包覆合金化改性纳米硅基负极材料；另一个主要的研究内容是使用硅烷偶联剂KH570和KH550对纳米硅的修饰改性，并采用原位聚合法制备聚苯胺包覆硅烷偶联剂改性纳米硅基负极材料；除此之外，还制备了原位聚合法制备聚苯胺包覆羧基修饰纳米硅基负极材料等。本文通过对掺杂态聚苯胺的合成条件研究，制备了具有电导率为26.0S/cm的高电导率掺杂态聚苯胺。通过超声化学镀铜改性纳米硅制得的硅基负极材料的首次效率为74.8%，首次可逆容量为1607.1mAh/g，50次循环后的容量保持率为64.9%，可逆容量为1042.9mAh/g。与纯纳米硅相比，循环稳定性有了较大的提升。通过原位聚合法制备的聚苯胺包覆合金化改性纳米硅基负极材料，其首次效率为71.2%，首次可逆容量为1115.0mAh/g，40次循环后的容量保持率为80.8%，可逆容量为901.3mAh/g。通过硅烷偶联剂KH570改性后的纳米硅，其最好的结果如下：首次效率为62.7%，首次可逆容量为1845.1mAh/g，20次循环后的容量保持率为115.4%，可逆容量为2129.9mAh/g。通过原位聚合法制备的聚苯胺包覆硅烷偶联剂KH570改性纳米硅基负极材料，其首次效率为65.1%，首次可逆容量为1631.7mAh/g，10次循环后的容量保持率为99.8%，可逆容量为1627.9mAh/g。相对于纯纳米硅来说，有了很大的性能提升。此外，还进行了硅烷偶联剂KH550以及硅羧基化的探索。
[Abstract]:In this paper, the surface modification of nano-silicon is carried out to improve its cyclic stability and efficiency, and thus improve its electrochemical performance. In this paper, the preparation of electroless copper-plated nano-silicon and high conductivity doped conductive Polyaniline was studied. Polyaniline coated and alloyed modified nano-silicon-based negative electrode materials were prepared by in-situ polymerization. Another main research content is the modification of nano-silicon with silane coupling agents KH570 and KH550, and the preparation of Polyaniline coated silane coupling agent to modify nano-silicon-based negative electrode material by in-situ polymerization. Polyaniline coated with carboxyl group modified nano-Si-based anode materials were also prepared by in-situ polymerization. In this paper, the doped Polyaniline with high conductivity of 26.0S / cm was prepared by studying the synthesis conditions of doped Polyaniline. The first efficiency of silicon based negative electrode prepared by ultrasonic electroless copper plating modified nano-silicon is 74.8, the first reversible capacity is 1607.1 mg / g and the capacity retention is 64.9 after 50 cycles, and the reversible capacity is 1042.9 mg / g. Compared with the pure nano silicon, the cycle stability has been greatly improved. Polyaniline coated and alloyed modified nanocrystalline silicon-based negative electrode materials prepared by in-situ polymerization have the initial efficiency of 71.2and the first reversible capacity of 1115.0mAh-gr after 40 cycles. The capacity retention and reversible capacity are 80.8 and 901.3 mAh/ g respectively. The results show that the first efficiency is 62.7, the first reversible capacity is 1845.1 mAh-gn, and the capacity retention is 115.4%, and the reversible capacity is 2129.9 mAh-1 路g ~ (-1) 路L ~ (-1) 路L ~ (-1). The results show that the best results are as follows: the first efficiency is 62.7%, the first reversible capacity is 184.1 mAh-g ~ (-1) after 20 cycles. Polyaniline coated silane coupling agent KH 570 was prepared by in-situ polymerization. The first efficiency was 65.1, the first reversible capacity was 1631.7 mg / g, the capacity retention was 99.8 and the reversible capacity was 1627.9mAh/ g. Compared with the pure nano silicon, the performance has been greatly improved. In addition, the silane coupling agent KH 550 and silicon carboxylation were also explored.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM912;TQ316.6

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