Viologen-based ionic conjugated mesoporous polymer as the electron conveyer for efficient polysulfide trapping and...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Commercialization of lithium-sulfur (Li-S) batteries is limited by polysulfide shuttle effect and slow redox kinetics.
• Developing effective cathode hosts is crucial for improving Li-S battery performance.

Purpose of the Study:

• To develop a novel cathode host material for Li-S batteries.
• To address the shuttle effect and enhance the electrochemical performance of Li-S batteries.

Main Methods:

• Synthesis of a viologen-based ionic conjugated mesoporous polymer (TpV-Cl).
• Modification of Li-S battery cathodes using the synthesized polymer as a host material.
• Electrochemical characterization including cycling performance and Coulombic efficiency.

Main Results:

• The S@TpV-PS cathode demonstrated excellent cycling stability, completing 300 cycles at 2.0 C with a low decay rate (0.032% per cycle).
• High sulfur loading (4.0 mg cm⁻²) was achieved with S@TpV-PS, maintaining excellent cycling stability and a Coulombic efficiency up to 98%.
• The viologen component acted as a reversible electron conveyor, improving polysulfide adsorption and conversion rates.

Conclusions:

• The developed viologen-based polymer (TpV-Cl) shows significant potential as a cathode host for high-performance Li-S batteries.
• The material effectively suppresses the shuttle effect and enhances redox kinetics, leading to improved battery longevity and efficiency.