A multifunctional self-supporting LLTO/C interlayer 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 but face challenges like slow redox kinetics, the shuttle effect, and lithium dendrite formation.
• These issues hinder the practical application and long-term stability of Li-S battery technology.

Purpose of the Study:

• To design and construct a multifunctional interlayer for Li-S batteries to address their inherent limitations.
• To enhance redox kinetics, promote lithium sulfide nucleation, and suppress lithium dendrite growth.

Main Methods:

• Fabrication of a binder-free, self-supporting interlayer using lithium lanthanum titanate (LLTO) and amorphous carbon nanofiber matrices.
• Systematic electrochemical testing to evaluate electrocatalytic properties and lithium deposition behavior in symmetric cells.

Main Results:

• The LLTO carbon matrix interlayer demonstrated sustained high specific capacity (703.3 mA h g⁻¹ after 200 cycles at 0.1C with 5.5 mg cm⁻² sulfur loading).
• Exceptional long-term cycling stability was achieved, with a capacity of 905.9 mA h g⁻¹ and a low decay rate (0.069% per cycle over 1000 cycles at 5C with 1 mg cm⁻² sulfur loading).

Conclusions:

• The developed multifunctional interlayer effectively facilitates LiPSs redox kinetics, promotes Li₂S nucleation, and inhibits lithium dendrite formation.
• LLTO carbon composite materials show significant potential as advanced interlayers for optimizing the performance of next-generation Li-S batteries.