A gel polymer electrolyte functionalized separator for high-performance lithium-sulfur batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-sulfur (Li-S) batteries offer high theoretical energy density and low cost, making them promising for future energy storage.
• The practical application of Li-S batteries is severely limited by the shuttle effect of soluble lithium polysulfides (LiPSs).

Purpose of the Study:

• To suppress the shuttle effect in Li-S batteries by modifying the separator.
• To enhance the electrochemical performance and cycling stability of Li-S batteries.

Main Methods:

• Modification of an Al2O3 separator with tris(pentafluorophenyl)borane (TPFPB).
• Induction of 1,3-dioxolane solvent ring-opening polymerization to form a gel layer on the separator.
• Electrochemical testing of Li-S batteries with the modified separator.

Main Results:

• The TPFPB-modified separator effectively suppressed the shuttle effect of LiPSs.
• A gel layer formed between the sulfur cathode and separator, improving Li-S battery performance.
• Li-S batteries with the TPFPB/Al2O3 separator exhibited excellent cycling stability and high capacity retention.

Conclusions:

• Tris(pentafluorophenyl)borane modification of separators is a viable strategy to mitigate the shuttle effect in Li-S batteries.
• Functional interface layers on separators can significantly improve the performance of Li-S batteries.
• This approach offers a promising guideline for designing high-performance Li-S energy storage devices.