Radical-scavengeable 2,4,6-tris(3-bromophenyl)-1,3,5-triazine anchored polyolefin separators for lithium metal...

Ensuring the reliable safety of the polyolefin-based separator has become increasingly challenging because of the growing demand for lithium-ion batteries. In this study, a flame-retardant and radical-scavenging compound, 2,4,6-tris(3-bromophenyl)-1,3,5-triazine (TBT), consisting of a functionalized triazine functional group, is incorporated into a poly(ethylene) (PE) separator via a one-step casting process and its physical, thermal, and electrochemical properties are explored. The incorporation of the TBT coating material enhances the mechanical properties of the PE separator, thereby effectively inhibiting the thermal shrinkage behaviors even at 180 °C. The TBT-coated PE separator exhibits a reliable affinity for carbonate-based electrolytes and remarkable radical scavenging properties without trade-off effects, affording desirable compatibility with conventional battery components. Electrochemical performance denotes that the TBT-coated PE separator effectively controls the dendritic Li growth at the Li anode and suppresses the undesired interfacial reactions occurring at the cathode because the TBT coating material reduces the concentration of highly reactive radicals. These results suggest that the TBT-coated PE separator is a potential separator for advanced batteries owing to its improved electrochemical and safety performance.