Metal-Organic Framework-derived Atomic Metal Sites Promoting Sulfur Cathode for All-Solid-State Lithium-Sulfur...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• All-solid-state lithium-sulfur batteries (ASSLSBs) promise high energy density and safety but suffer from slow redox kinetics and poor sulfur utilization.
• Conductive materials in sulfur cathodes can improve charge transfer and sulfur conversion efficiency.

Purpose of the Study:

• To introduce a novel cobalt-nitrogen-doped carbon (Co-NC) material derived from a metal-organic framework (MOF) for ASSLSBs.
• To investigate the impact of Co-NC on the electrochemical performance of ASSLSBs, focusing on charge transfer and sulfur utilization.

Main Methods:

• Synthesis of Co-NC from a MOF precursor.
• Fabrication of Co-NC@S cathodes for ASSLSBs.
• Electrochemical characterization including cycling performance and rate capability at various temperatures.

Main Results:

• The Co-NC material exhibits atomically dispersed Co-N sites and conductive carbon pathways, enhancing charge transfer.
• Co-NC@S cathodes demonstrated a high initial capacity of 1499 mAh g^-1 at C/20 with a sulfur loading of 5 mg cm^-2.
• ASSLSBs with Co-NC achieved a capacity of 903 mAh g^-1 at 5C and 60 °C, significantly outperforming those without Co-NC.

Conclusions:

• The MOF-derived Co-NC material effectively addresses sluggish redox kinetics and poor sulfur utilization in ASSLSBs.
• This approach offers a practical strategy for developing high-energy, high-rate, and safe ASSLSBs.