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.

Key words: Lithium-sulfur battery, CC/NiS₂, interlayer, electrocatalyst