POS6-0195
Bio-Derived Phytic Acid-Based Organic-Inorganic Hybrid Coating for Flame-Retardant and Thermally Stable Separators for Lithium-Ion Batteries
When and Where
Nov 30, -0001
12:00am - 12:00am
Presenter(s)
Gwangbin Won (Seoul National University)
Co-Author(s)
Abstract
As lithium-ion batteries are increasingly required to deliver higher energy density, separator safety has become a critical issue because commercial polyolefin separators suffer from severe thermal shrinkage and flammability under abusive conditions. Herein, we present a bio-derived phytic acid-based organic–inorganic hybrid coating strategy for flame-retardant and thermally stable polyethylene separators. The hybrid coating, denoted as PGPB, was constructed from phytic acid-functionalized glycidyl methacrylate, poly(acrylic acid), ethoxylated trimethylolpropane triacrylate, and boehmite particles, forming a cross-linked polar network on both sides of a commercial PE separator. The phytic acid-derived phosphorus groups and boehmite particles provide complementary flame-retardant functions through condensed-phase char formation, radical scavenging, endothermic dehydration, and ceramic barrier formation. As a result, the PGPB@PE separator exhibited significantly improved dimensional stability at elevated temperature and reduced self-extinguishing time compared with pristine PE. In addition, the polar functional groups, including phosphate, carboxyl, and Al–OH moieties, enhanced electrolyte affinity and promoted more uniform electrolyte penetration into the separator. Consequently, PGPB@PE showed increased electrolyte uptake, higher ionic conductivity, and improved Li⁺ transference number. The modified separator also enabled stable cycling performance in NCM811/Li cells by mitigating interfacial resistance growth during repeated charge–discharge processes. These results demonstrate that the bio-derived organic–inorganic hybrid coating simultaneously improves thermal safety, flame retardancy, electrolyte transport, and interfacial stability. This work provides a practical and multifunctional separator design strategy for safer and high-performance lithium-ion batteries.
