Sulfonic Group Modified Binder Endows Rapid Lithium-Ion Diffusion for SiO Microparticle Anode.

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Silicon anodes offer high specific capacity but suffer from poor cycling stability due to large volume expansion and particle pulverization.
• These issues lead to stress concentration, loss of electrical contact, and degraded battery performance.

Purpose of the Study:

• To develop an ion-conductive binder that enhances the electrochemical performance of silicon-based anodes.
• To address the challenges of volume expansion and particle pulverization in silicon anodes.

Main Methods:

• Free radical polymerization of acrylic acid and lithiated 2-acrylamido-2-methyl-1-propanesulfonic acid (LiAMPS) to create an ion-conductive binder.
• Incorporation of sulfonic acid anionic groups for enhanced lithium-ion diffusion.
• Utilizing noncovalent hydrogen bonds for improved mechanical properties to alleviate stress.

Main Results:

• The P(AA-co-LiAMPS) binder significantly improved lithium-ion diffusion kinetics and rate performance.
• The binder effectively alleviated stress concentration, preventing particle pulverization and maintaining electrode structural integrity.
• Silicon microparticle anodes with the new binder achieved a capacity of 587.8 mAh g⁻¹ after 400 cycles at 1C and 648.6 mAh g⁻¹ at 5C.

Conclusions:

• The synergistic strategy of enhancing ion diffusion and mechanical stability provides a promising approach for high-performance silicon anodes.
• The developed ion-conductive binder demonstrates significant potential for advancing high-energy-density battery technologies.