Stable High-Capacity Elemental Sulfur Cathodes with Simple Process for Lithium Sulfur Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-sulfur (Li-S) batteries offer high energy density, making them ideal for drones.
• Challenges include poor sulfur conductivity and polysulfide shuttling, limiting cathode performance.
• Existing sulfur-carbon composites are costly and have low sulfur content, restricting areal capacity.

Purpose of the Study:

• To develop stable sulfur cathodes with high areal specific capacity for Li-S batteries.
• To mitigate polysulfide shuttling and improve energy density at a reduced cost.
• To enable mass production of practical Li-S battery devices.

Main Methods:

• Utilized composite current collectors, specific binders, and carbonaceous matrices for sulfur impregnation.
• Achieved high sulfur loading (3.8 mg/cm²) by ensuring good adhesion between components.
• Investigated the impact of binder swelling and electroconductivity on cycling performance.

Main Results:

• Successfully reached a high sulfur loading of 3.8 mg/cm² with a specific/areal capacity of 805 mAh/g/2.2 mAh/cm².
• Demonstrated that composite electrodes with high sulfur loading require non-swelling binders for stable cycling.
• Electroconductivity was found to be the dominant factor in cycling performance for high-sulfur-loaded Li-S cells.

Conclusions:

• A composite electrode design incorporating carbonaceous matrices, high sulfur loading, and non-swelling binders is crucial for high-performance Li-S batteries.
• This approach effectively addresses conductivity and shuttling issues, leading to improved energy density.
• The proposed design is amenable to mass production for practical energy storage devices.