Double-Layered Modified Separators as Shuttle Suppressing Interlayers for Lithium-Sulfur Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Polysulfide shuttling in lithium-sulfur batteries causes significant capacity loss.
• Separator modification is a key strategy to mitigate these detrimental effects.
• Developing advanced separators is crucial for high-performance lithium-sulfur batteries.

Purpose of the Study:

• To design and investigate a novel double-layered separator for lithium-sulfur batteries.
• To suppress polysulfide shuttling and enhance electrochemical performance.
• To improve the overall efficiency and longevity of lithium-sulfur cells.

Main Methods:

• Fabrication of a double-layered separator combining a polypropylene (PP) matrix and poly(methyl methacrylate) (PMMA) microsphere layer.
• Electrochemical testing of sulfur positive electrodes with the novel PP/PMMA separator and a standard PP separator.
• Analysis of capacity, Coulombic efficiency, and polysulfide inhibition mechanisms.

Main Results:

• The PP/PMMA separator achieved a high initial capacity of 1100.10 mAh g^-1 at 0.1 mA cm^-2, exceeding the standard PP separator's 948.60 mAh g^-1.
• The arrayed PMMA microspheres effectively inhibited polysulfide diffusion via physical and chemical adsorption.
• Enhanced electrolyte affinity and accelerated lithium-ion diffusion were observed with the PMMA microspheres.

Conclusions:

• The developed double-layered PP/PMMA separator significantly suppresses polysulfide shuttling in lithium-sulfur batteries.
• This separator design leads to superior electrochemical performance, including higher capacity and efficiency.
• The findings highlight the potential of engineered separators for advancing lithium-sulfur battery technology.