Stabilizing All-Solid-State Li-S Batteries by a Polysulfide-Repelling and Anode-Protecting Self-Segregated Trilayer...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Stable, high-energy-density lithium-sulfur (Li-S) batteries require rational management of lithium polysulfide (LiPS) transport.
• The shuttle effect of LiPS and unstable lithium metal anode operation hinder Li-S battery performance.

Purpose of the Study:

• To develop a freestanding, self-segregated trilayer polymer electrolyte (TLE) for enhanced Li-S battery stability and performance.
• To investigate the dual-functional coatings of the TLE in repelling LiPS and stabilizing the Li metal anode.

Main Methods:

• Fabrication of a freestanding, self-segregated trilayer polymer electrolyte (TLE) via a single-step casting process.
• Autonomous phase separation of immiscible polymers to form ion-selective coatings at interfaces.
• Operando optical cell monitoring and theoretical modeling to analyze coating functionality.

Main Results:

• The TLE's dual-functional coatings simultaneously repel dissolved LiPS and stabilize Li metal plating/stripping.
• Effective suppression of the shuttle effect and stable Li metal anode operation were achieved.
• Initial discharge capacity of 1369 mAh g^-1 (81.7% of theoretical) with stable capacity over 50 cycles at 0.2C.

Conclusions:

• The developed TLE offers a practical and scalable solution for durable, high-performance Li-S batteries.
• The self-segregated coatings provide a robust strategy for overcoming key challenges in Li-S battery technology.
• This approach paves the way for advanced all-solid-state Li-S batteries.