Hierarchical Carbon Interlayer Design as Interfacial Stabilizer and In-Situ Solid-Electrolyte Infiltrate for...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-sulfur (Li-S) batteries offer high energy density but are hindered by the polysulfide shuttle effect in liquid electrolytes.
• Gel polymer electrolytes (GPEs) are explored as a solution due to their potential for high ionic conductivity and interfacial stability.

Purpose of the Study:

• To develop an in-situ polymerized GPE integrated with a hierarchical carbon interlayer for high-performance solid-state Li-S batteries.
• To address the shuttle effect and improve sulfur utilization and overall electrochemical performance.

Main Methods:

• In-situ ring-opening polymerization of DOL initiated by Al(OTf)₃ to form GPEs.
• Fabrication of a hierarchical carbon interlayer using aligned carbon nanotubes and Super P with a 0.76 nm size exclusion effect.
• Integration of GPEs and the carbon interlayer to create HC@PP separators.

Main Results:

• GPEs achieved ionic conductivity of 1.74 mS cm^-1 and low interfacial impedance.
• The HC@PP separator demonstrated enhanced interface stability and polysulfide conversion.
• Li-S batteries with HC@PP separators showed high discharge capacity (1332 mAh g^-1), improved rate capability, and 80% capacity retention after 150 cycles.

Conclusions:

• The in-situ polymerization strategy for GPEs combined with a hierarchical carbon interlayer offers effective interface regulation.
• This approach significantly enhances the performance of solid-state Li-S batteries by mitigating the shuttle effect.
• The developed HC@PP separators represent a promising advancement for next-generation energy storage solutions.