In Situ Built ZnS/MXene Heterostructure by a Mild Method for Inhibiting Polysulfide Shuttle in Li-S Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• MXene-derived heterostructures show promise for lithium-sulfur (Li-S) batteries due to high surface area and catalytic activity.
• Conventional synthesis methods for these heterostructures involve high temperatures, risking MXene oxidation and reduced conductivity.

Purpose of the Study:

• To develop a mild synthesis route for MXene-based heterostructures for Li-S batteries.
• To investigate the catalytic properties of ZnS/MXene heterostructures in accelerating sulfur redox kinetics and mitigating the shuttle effect.

Main Methods:

• Synthesized a two-dimensional ZnS/MXene heterostructure using a mild, low-temperature method.
• Characterized the material to confirm the retention of MXene structure and the in-situ growth of ZnS nanospheres.
• Fabricated Li-S batteries utilizing ZnS/MXene modified separators.

Main Results:

• The mild synthesis preserved the MXene nanosheet structure without oxidation, maintaining electrical conductivity.
• In-situ grown ZnS nanospheres prevented MXene restacking, increasing active sites and facilitating lithium-ion transport.
• The ZnS/MXene modified separators demonstrated a high initial discharge capacity (1230 mAh/g at 0.1 C) and excellent cycle stability (0.082% decay per cycle after 500 cycles at 0.5 C).

Conclusions:

• The developed mild method successfully produced ZnS/MXene heterostructures suitable for Li-S batteries.
• The ZnS/MXene heterostructure effectively accelerates polysulfide conversion and suppresses the shuttle effect through enhanced electron/ion migration.
• This work provides a valuable reference for fabricating advanced MXene-based heterostructures for high-performance Li-S batteries.