高等学校化学学报 ›› 2023, Vol. 44 ›› Issue (11): 20230354.doi: 10.7503/cjcu20230354

• 物理化学 • 上一篇    

氮掺杂碳包覆rGO-纳米硅的制备及电化学性能

周惠1, 朱帅波1, 王际童1, 乔文明1(), 余子舰2, 张寅旭2   

  1. 1.华东理工大学化学工程联合国家重点实验室, 上海 200237
    2.合盛硅业(鄯善)有限公司, 吐鲁番 838200
  • 收稿日期:2023-08-01 出版日期:2023-11-10 发布日期:2023-09-15
  • 通讯作者: 乔文明 E-mail:qiaowm@ecust.edu.cn
  • 基金资助:
    国家自然科学基金(22178107);新疆维吾尔自治区重点项目(2022B01030)

Construction and Electrochemical Properties of Si/rGO@CN as Anode Materials for High-performance Lithium-ion Batteries

ZHOU Hui1, ZHU Shuaibo1, WANG Jitong1, QIAO Wenming1(), YU Zijian2, ZHANG Yinxu2   

  1. 1.State Key Laboratory of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China
    2.Hesheng Silicon Industry(Shanshan) Co. Ltd. ,Tolufan 838200,China
  • Received:2023-08-01 Online:2023-11-10 Published:2023-09-15
  • Contact: QIAO Wenming E-mail:qiaowm@ecust.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(22178107);the Xinjiang Uygur Autonomous Region Key Research and Development Program, China(2022B01030)

摘要:

通过静电自组装法, 将自带负电的石墨烯与用正电荷修饰过的纳米硅进行自组装, 再利用多巴胺的黏接特性对复合材料进行氮掺杂碳包覆得到复合材料Si/rGO@CN. 通过改变多巴胺的浓度和聚合时间, 研究了不同厚度的氮掺杂碳层对复合材料电化学性能的影响. 结果显示, 当氮掺杂碳的含量(质量分数)为23.6%时, 复合材料表现出优异的电化学性能. 在0.2 A/g电流密度下循环200次后容量为943.4 mA·h/g; 在1.0 A/g电流密度下的长循环性能测试中, 发现其经300次循环后容量仍然保持在753.8 mA·h/g. 氮掺杂碳层的均匀连续包覆不仅可以避免硅与电解液的直接接触, 还可以缓冲硅纳米材料在脱嵌锂时产生的体积膨胀, 维持材料结构的稳定性, 而石墨烯的存在提高了复合材料的导电性.

关键词: 锂离子电池, 负极材料, 硅碳复合, 纳米硅, 碳包覆

Abstract:

In this paper, the self-charged graphene and the nano-silicon modified with positive charge were self- assembled by electrostatic self-assembly method, and then the dopamine bonding characteristics was used to nitrogen-doped carbon coating of the composite material to obtain Si/rGO@CN composites, and the effect of different thicknesses of nitrogen-doped carbon layers on the electrochemical performance of the composite materials was studied by changing the concentration and polymerization time of dopamine. The electrochemical results showed that when the content of nitrogen-doped carbon was 23.6%(mass fraction), the composite showed excellent electro- chemical performance. The capacity of the composite was 943.4 mA·h/g after 200 cycles at a current density of 0.2 A/g, and its capacity remained at 753.8 mA·h/g after 300 cycles in the long cycle performance test at a current density of 1.0 A/g. The uniform continuous coating of the nitrogen-doped carbon layer can not only avoid the direct contact between silicon and electrolyte, but also buffer the volume expansion generated by silicon nanomaterials during lithium intercalation and maintain the stability of the material structure. The presence of graphene improves the conductivity of composite materials.

Key words: Lithium-ion battery, Anode material, Silicon-carbon composite, Nanosilicon, Carbon coating

中图分类号: 

TrendMD: