Formation of Nanochannels Using Polypropylene and Acetylcellulose for Stable Separators

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Lithium-ion batteries require separators with high thermal stability to prevent short circuits and ensure safety.
• Current polymer separators often lack sufficient thermal durability, limiting battery performance under demanding conditions.

Purpose of the Study:

• To develop a polymer separator with enhanced thermal stability for lithium-ion batteries.
• To investigate the role of glycerin in improving the properties of acetyl cellulose-based separators.

Main Methods:

• A composite separator was fabricated by coating acetyl cellulose and glycerin onto a polypropylene (PP) membrane.
• The coated membrane underwent a water treatment process to modify pore structure and enhance inter-layer adhesion.
• Scanning Electron Microscopy (SEM) was used to analyze pore morphology.
• Thermogravimetric Analysis (TGA) and Fourier-Transform Infrared Spectroscopy (FT-IR) were employed to assess thermal stability and chemical interactions.

Main Results:

• The addition of glycerin plasticized acetyl cellulose, promoting pore formation and flexibility.
• Double coating and water treatment enhanced pore connectivity and interaction between PP and acetyl cellulose layers.
• The modified separator demonstrated an average water flux of 1.42 LMH.
• Decomposition temperature increased by approximately 60 °C compared to neat acetyl cellulose, indicating improved thermal stability.

Conclusions:

• The developed acetyl cellulose-glycerin composite separator offers significantly enhanced thermal stability for lithium-ion battery applications.
• The study confirms chemical interactions between acetyl cellulose functional groups and the polypropylene substrate.
• This approach provides a viable strategy for improving the safety and durability of lithium-ion battery separators.