自支撑CC/NiS2纳米片中间层制备与锂硫电池性能研究*

Synthesis of Self-supported CC/NiS2 Nanosheet as an Interlayer and Its Performance Research of Lithium-sulfur Battery

  • 摘要: 多硫离子的穿梭效应是限制锂硫电池发展的一个关键问题。通过水热法和进一步的硫化反应合成了自支撑的碳布/二硫化镍纳米片(CC/NiS2)复合材料,并将其用作锂硫电池中间层来有效抑制多硫离子的穿梭效应。NiS2纳米片均匀生长在CC表面,具有较大的比表面积和优异的催化活性,能够显著增强对多硫离子的化学吸附能力并促进电化学反应动力学。相比于碳布(CC)中间层电池,CC/NiS2中间层电池具有明显提高的倍率性能和良好的循环寿命,在0.5C下放电的初始比容量为1 254 mA·h·g-1(增加52%),在2C下循环300圈后的比容量仍高达928 mA·h·g-1,容量衰减率仅为每圈0.015%。

     

    Abstract: The shuttle effect of soluble polysulfides is a key issue that limits the development of lithium-sulfur batteries. The self-supported NiS2 nanosheets modified carbon cloth(CC/NiS2) is synthesized by a hydrothermal method coupled with post-vulcanization reaction, and used as a multifunctional interlayer of lithium-sulfur battery(LSB) to inhibit the shuttle effect. NiS2 nanosheets that are vertically grown on the surface of CC have a large specific surface area and excellent catalytic activity, which can significantly enhance the chemisorption capacity of polysulfide species and promote electrochemical reaction kinetics. Compared with the LSB with a carbon cloth(CC) interlayer, the LSB with the CC/NiS2 interlayer exhibits significantly improved rate performance and outstanding cycling stability. The initial specific capacity discharged at 0.5C has an increase by 52% and reaches 1 254 mA·h·g-1. The LSB with the CC/NiS2 interlayer can still maintain a high specific capacity of 928 mA·h·g-1 after 300 cycles at 2C, and the capacity decay rate is only 0.015% per cycle.

     

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