The Polymer Society of Korea

Abstract

Lithium-ion batteries (LIBs) are widely used in portable electronics or electric vehicles due to their high energy density and long cycle life. Polyolefin-based separators, particularly polypropylene (PP), are commonly utilized because of their low cost and moderate mechanical properties. However, their inherent limitations—such as poor thermal dimensional stability, insufficient electrolyte wettability, and limited mechanical robustness—remain significant challenges for advanced battery applications. In this study, we propose a surface-engineering approach based on tailored coating layers to improve the mechanical robustness and thermal resistance of PP-based separators while enhancing electrochemical performances. By systematically optimizing the coating thickness while selecting functionalized polymers, this study aims to establish a design framework for achieving well-balanced separator performance without compromising negative effects due to overcoating.