High Energy Density Lithium-Sulfur Batteries Based on Carbonaceous Two-Dimensional Additive Cathodes

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Growing demand for electrical energy storage necessitates alternatives to current lithium-ion batteries.
• Lithium-sulfur batteries (LSBs) offer potential due to sulfur's low cost and high theoretical capacity.
• LSBs face challenges including poor conductivity and polysulfide shuttling, hindering commercialization.

Purpose of the Study:

• To develop high-performing lithium-sulfur batteries (LSBs) using functional carbonaceous additives.
• To investigate the impact of in-house synthesized graphene-based porous carbon (ResFArGO) and commercial conductive carbons (CAs) on sulfur cathode performance.
• To demonstrate a facile, scalable strategy for advanced LSB cathode development.

Main Methods:

• Formulation of sulfur cathodes using three different carbonaceous additives: ResFArGO (two variations) and CAs.
• Electrochemical characterization to evaluate conductivity enhancement, C-rate performance, and capacity retention.
• Assessment of polysulfide trapping ability and scalability through prototype pouch cell assembly.

Main Results:

• Carbon additives significantly improved electrochemical properties and electronic conductivity of sulfur electrodes.
• Remarkable capacities achieved: 4.3, 4.0, and 3.6 mA h cm⁻² at C/10 for ResFArGO₁₀, ResFArGO₅, and CAs, respectively.
• ResFArGO cathodes demonstrated high sulfur loading (>4 mgS cm⁻²) and effective polysulfide trapping; prototype cells showed excellent capacities (90 mA h and 70 mA h).

Conclusions:

• Functional carbonaceous additives provide a scalable strategy for developing high-performance LSBs.
• The developed ResFArGO and CAs enhance electrode conductivity and polysulfide management, overcoming key LSB limitations.
• The successful assembly of prototype pouch cells validates the system's potential for practical energy storage applications.