High performance separator coated with amino-functionalized SiO₂ particles for safety enhanced lithium-ion batteries

Abstract

Amino-functionalized SiO2 (N-SiO2) particles were synthesized and used to coat both sides of a porous polyethylene separator. The N-SiO2 coated separator exhibited good wettability by liquid electrolyte, high ionic conductivity when soaked with liquid electrolyte and enhanced thermal stability at high temperatures. By employing the N-SiO2 coated separator in fabricating the lithium-ion cell composed of a graphite negative electrode and a LiNi1/3Co1/3Mn1/3O2 positive electrode, its cycling stability was improved compared to a cell assembled with either a conventional polyethylene separator or a SiO2 coated polyethylene separator. The NSiO2 coated separator is a promising separator to enhance the cycling stability and thermal safety of lithium-ion battery.