Fabrication and Evaluation of Si 3 N 4 -coated Organic/inorganic Hybrid Separators for Lithium-ion Batteries

Abstract

Polyethylene (PE) separator is the most popular separator for lithium-ion batteries. However,it suffers from thermal contraction and mechanical rupture. In order to improve the thermal/mechanical dimensional stabilities, this study investigated the effects of Si3N4 coating. SCS (Silicon-nitride Coated Separator) has been fabricated by applying 10 μm-thick Si3N4/PVdF coating on one side of PE separator. SCS exhibits enhanced thermal stability over 100~150οC: its thermal shrinkage is reduced by 10~20% compared with pristine PE separator. In addition, SCS shows higher tensile strength than PE separator. Employing SCS hardly affects the C-rate performance of LiCoO2/Li coin-cell, even though its ionic conductivity is somewhat lower than that of PE separator. PU - The Korean Electrochemical Society