A rice husk-derived SiO/C composite for effective lithium-sulfur battery separator modification

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-sulfur (Li-S) batteries possess high theoretical energy density but suffer from the polysulfide shuttle effect and poor conductivity.
• These issues limit reversibility and cycle life, hindering practical applications.
• Separator modification is a key strategy to address these challenges in Li-S battery design.

Purpose of the Study:

• To develop a sustainable and effective separator modification material for high-performance Li-S batteries.
• To investigate the synergistic effects of silica and porous carbon derived from rice husks.
• To improve sulfur utilization and electrochemical performance of Li-S cells.

Main Methods:

• Synthesis of a silica/porous carbon composite (S-MRH) from rice husk using a salt-assisted method.
• Coating a polypropylene separator with the S-MRH composite (S-MRH/PP).
• Electrochemical characterization of the S-MRH/PP separator in Li-S cells, including capacity, rate performance, and cycling stability.

Main Results:

• The S-MRH composite effectively suppresses polysulfide dissolution via silica's catalytic effect and enhances conductivity through the porous carbon network.
• The S-MRH/PP separator achieved a high specific capacity of 1507.7 mA h g⁻¹ at 0.1C and superior rate performance (766.5 mA h g⁻¹ at 3C).
• Excellent cycling stability was observed even under demanding conditions like high sulfur loading and lean electrolytes.

Conclusions:

• Biomass-derived S-MRH composite is a viable and sustainable material for enhancing Li-S battery separators.
• The synergistic interaction between amorphous silica and porous carbon significantly improves Li-S battery performance.
• This approach offers valuable insights for designing advanced materials for various energy storage systems.