Solvent-Free Dry-Process Enabling High-Areal Loading Selenium-Doped SPAN Cathodes Toward Practical Lithium-Sulfur...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Current dry-processed cathodes face challenges with structural integrity and performance under high-loading conditions.
• Selenium-sulfur cathodes are promising for high-energy-density batteries but suffer from volume expansion issues.

Purpose of the Study:

• To develop a robust dry-processed selenium-doped sulfurized polyacrylonitrile (Se-SPAN) cathode using multi-walled carbon nanotubes (MWCNT) and polytetrafluoroethylene (PTFE).
• To investigate the electrochemical-mechanical properties of the dry-processed Se-SPAN (D/Se-SPAN) and compare it with slurry-processed counterparts.
• To provide design guidelines for high-loading, cost-effective, and eco-friendly sulfur-based dry cathodes.

Main Methods:

• Fabrication of D/Se-SPAN cathodes via a dry process incorporating MWCNT and PTFE binder.
• Characterization of the D/Se-SPAN structure for density, robustness, and uniformity.
• Electrochemical-mechanical investigations to assess performance under ultra-high-loading conditions.
• Comparative analysis against traditional slurry-processed Se-SPAN (S/Se-SPAN) cathodes.

Main Results:

• The D/Se-SPAN exhibits a dense, robust, and uniform structure that mitigates internal stress evolution.
• Achieved reversible areal capacities of approximately 31.8 mAh cm⁻² under ultra-high-loading conditions (64.2 mg_Se-SPAN cm⁻²).
• Demonstrated remarkable cycle stability, outperforming traditional slurry-processed cathodes.

Conclusions:

• The dry-processing method significantly enhances the structural integrity and electrochemical performance of Se-SPAN cathodes.
• D/Se-SPAN offers a viable pathway for high-loading, stable, and durable sulfur-based battery cathodes.
• The study provides critical insights for developing next-generation, cost-effective, and sustainable energy storage solutions.