Mo₂C Electrocatalysts for Kinetically Boosting Polysulfide Conversion in Quasi-Solid-State Lithium-Sulfur Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-sulfur batteries (LSBs) face challenges with slow reaction kinetics and polysulfide (PSs) dissolution in liquid electrolytes, limiting their performance.
• Improving sulfur species kinetics and mitigating PSs shuttle effect are crucial for high-performance LSBs.

Purpose of the Study:

• To enhance the electrochemical performance and durability of lithium-sulfur batteries.
• To address sluggish reaction kinetics and polysulfide dissolution issues in LSBs.

Main Methods:

• Decorating molybdenum carbide (Mo2C) nanoparticles on carbon nanotubes (CNTs) as a host for sulfur active mass.
• Utilizing gel polymer electrolytes (GPEs) from in situ polymerization of 1,3-dioxolane (DOL) to reduce PSs diffusion and stabilize Li stripping/plating.
• Fabricating quasi-solid-state LSBs with CNT/Mo2C/S cathodes and GPEs.

Main Results:

• Enhanced initial specific capacity and suppressed dissolution of sulfur species in the sulfur cathodes.
• Remarkably improved lithium plating-stripping behavior at the anode when using GPEs.
• Synergistic effects leading to higher energy density and improved durability in the developed LSBs.

Conclusions:

• The developed CNT/Mo2C/S cathodes combined with GPEs offer a promising strategy for high-performance LSBs.
• This approach demonstrates a viable pathway for creating advanced quasi-solid-state lithium metal batteries with enhanced stability and energy density.