Recent Advances in Polyphenylene Sulfide-Based Separators for Lithium-Ion Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Polyphenylene sulfide (PPS) separators are crucial for next-generation lithium-ion batteries (LIBs) due to their high thermal stability (>260 °C), chemical inertness, and mechanical strength.
• Current separator technologies face limitations in performance and safety under demanding operational conditions.

Purpose of the Study:

• To comprehensively review advancements in PPS separator design for high-performance LIBs.
• To analyze the distinct properties and fabrication methods of porous and nonporous PPS separators.
• To identify challenges and future directions for PPS-based energy storage systems.

Main Methods:

• Review of wet-chemical methods (melt-blown spinning, electrospinning, thermally induced phase separation) for porous PPS separators.
• Examination of solvent-free dry-film processes for nonporous solid-state PPS separators.
• Analysis of COMSOL simulations for dendrite mitigation and electric field distribution in dry-processed separators.

Main Results:

• Porous PPS separators (<1 μm pores) achieve high ionic conductivity (>1 mS·cm⁻¹) at >55% porosity.
• Nonporous solid-state PPS separators exhibit excellent thermal dimensional stability (<2% shrinkage at 280 °C) and ion transference numbers >0.8.
• Dry-processed separators demonstrate dendrite suppression and uniform lithium deposition, even with contaminants.

Conclusions:

• PPS separators, both porous and nonporous, offer significant advantages for advanced LIBs, including enhanced safety and energy density (>500 Wh·kg⁻¹).
• Key challenges include optimizing thickness, scaling solvent-free manufacturing, and reducing costs.
• Future innovations like ultra-thin formats, self-healing networks, and compatibility with other ion systems (Na/Zn) are critical for widespread adoption in electric vehicles and grid storage.