Garlic-braid-derived activated biochar as a high-performance sulfur host for lithium-sulfur batteries

Area of Science:

• Materials Science
• Electrochemistry
• Sustainable Energy

Background:

• Lithium-sulfur (Li-S) batteries offer high theoretical energy density but face challenges like low sulfur conductivity and polysulfide shuttle.
• Developing efficient and sustainable sulfur hosts is crucial for advancing Li-S battery technology.

Purpose of the Study:

• To investigate garlic-braid-derived biochar as a sustainable sulfur host for Li-S battery cathodes.
• To engineer a porous carbon matrix from biomass for improved electrochemical performance.

Main Methods:

• Garlic braid biomass was chemically activated using potassium hydroxide to create a porous biochar.
• Sulfur was infiltrated into the activated biochar to form a composite cathode material.
• Electrochemical performance of the Li-S cells using the composite cathode was evaluated.

Main Results:

• The activated biochar exhibited a hierarchical porous structure with 48 wt.% sulfur loading.
• The optimized cathode achieved an initial discharge capacity of 1,015 mAh/g, stabilizing at ~700 mAh/g after 80 cycles at 0.1 C.
• A capacity of 491 mAh/g was maintained at 1 C, indicating good rate capability and stable cycling performance.

Conclusions:

• Garlic-braid-derived activated biochar effectively confines sulfur and facilitates ion transport, enhancing Li-S battery performance.
• Pore structure engineering and biomass selection are key for developing high-performance biochar-based cathodes.
• This study presents a promising, sustainable approach for advanced Li-S battery development.