Rational Design of Crosslinked Polymeric Microsphere Coatings for Thermally Stable and Swelling-Resistant Lithium-Ion...

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Lithium-ion battery separators require high thermal stability, low swelling, and electrolyte wettability.
• Conventional ceramic coatings increase weight and reduce porosity.
• Acrylate-based polymer coatings often lack sufficient heat resistance.

Purpose of the Study:

• To engineer a new class of polymeric microspheres for advanced lithium-ion battery separators.
• To overcome the limitations of existing separator coating technologies.
• To enhance separator performance, focusing on thermal stability, swelling resistance, and wettability.

Main Methods:

• Emulsion polymerization of styrene, methyl methacrylate, acrylonitrile, and dipentaerythritol hexaacrylate.
• Synthesis of highly crosslinked, monodisperse polymeric microspheres.
• Application of microspheres as thin (∼1.5 µm) separator coatings.

Main Results:

• Microspheres exhibit high thermal robustness (T₃ up to 370°C) and low electrolyte swelling (<11%).
• Coated separators show minimal thermal shrinkage (5.6% at 150°C) and enhanced electrolyte infiltration.
• Improved ionic conductivity (0.80 mS cm^-1) and superior cycling stability in pouch cells.

Conclusions:

• The developed polymeric microspheres offer a high-performance, lightweight, and scalable alternative to ceramic coatings.
• These microspheres significantly enhance lithium-ion battery separator performance and safety.
• The engineered microspheres pave the way for next-generation battery technologies.