Molten Lean-Lithium Infiltrated Into a Lithiophilic 3D Carbon Framework for High-Performance Lithium-Sulfur Cells.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-sulfur (Li-S) batteries offer high theoretical energy density but face practical limitations.
• Conventional lithium-metal anodes suffer from instability, dendrite growth, and mass issues, especially under lean conditions.
• These challenges hinder the commercial viability of high-energy Li-S batteries.

Purpose of the Study:

• To address the limitations of conventional lithium-metal anodes in Li-S batteries.
• To develop a stable and practical anode for high-energy-density Li-S cells.
• To enable uniform lithium infiltration and long-term cycling stability.

Main Methods:

• Fabrication of a molten lean-lithium anode on a lithiophilic SiO2-coated 3D conductive carbon framework.
• Electrochemical characterization to evaluate anode performance and Li-S cell cycling.
• Testing of Li-S full cells with high-loading polysulfide cathodes and low electrolyte-to-sulfur ratios.

Main Results:

• The 3D architecture facilitated homogeneous current distribution and lithium nucleation, suppressing dendrite growth and volume expansion.
• Electrochemical tests showed enhanced redox kinetics, reduced polarization, and improved Coulombic efficiency.
• The Li-S full cell achieved 909 mAh g⁻¹ initial capacity, maintained 500 mAh g⁻¹ after 200 cycles at C/10, and showed stable high-rate performance without dendritic failure.

Conclusions:

• The developed molten lithium anode strategy effectively overcomes critical challenges associated with lithium-metal anodes.
• This scalable and cost-effective approach provides a practical pathway for realizing high-energy-density Li-S batteries.
• The use of a SiO2-coated 3D carbon framework enables stable and efficient lithium metal utilization.