Bifunctional K₃PW₁₂O₄₀/Graphene Oxide-Modified Separator for Inhibiting Polysulfide Diffusion and Stabilizing Lithium...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-sulfur (Li-S) batteries offer high theoretical energy density but face challenges like polysulfide shuttle and lithium dendrite growth.
• These issues limit the practical application and cycle life of Li-S batteries.
• Developing advanced separators is crucial for overcoming these limitations.

Purpose of the Study:

• To introduce a bifunctional K3PW12O40/graphene oxide-modified polypropylene separator (KPW/GO/PP) for Li-S batteries.
• To mitigate polysulfide diffusion and protect the lithium anode.
• To enhance the overall performance and stability of Li-S batteries.

Main Methods:

• Fabrication of a KPW/GO/PP separator by incorporating K3PW12O40 into a graphene oxide-modified polypropylene membrane.
• Electrochemical evaluation of the separator's ability to capture and convert lithium polysulfides (LiPSs).
• Analysis of lithium anode stabilization and dendrite suppression during cycling.

Main Results:

• The KPW/GO/PP separator effectively suppressed the polysulfide shuttling effect.
• It stabilized the lithium metal anode, preventing dendrite formation and ensuring a uniform lithium metal surface.
• Achieved an initial specific capacity of 1006 mAh g-1 and 626 mAh g-1 after 500 cycles at 1.0 C with a low decay rate of 0.075% per cycle.

Conclusions:

• The bifunctional KPW/GO/PP separator is a highly effective solution for improving Li-S battery performance.
• Synergistic effects of KPW and GO enhance polysulfide management and anode protection.
• This separator demonstrates significant potential for advancing next-generation Li-S battery technology.