The Polymer Society of Korea

Abstract

High-energy lithium-ion batteries (LIBs) require polymer binders that maintain mechanical integrity under high mass-loading. While polyvinylidene (PVDF) is electrochemically stable, its poor adhesion often leads to electrode delamination and capacity fading. Although modified PVDF binders have been explored, most lack systematic control over polymer structure. Here, we develop PVDF-g-polyacrylic acid (PAA) (PVDFA) binders with carboxylic acid functional groups to improve interfacial adhesion. By tuning side-chain length and spacing, we identify key structural parameters that govern adhesion and cycling durability. Enhanced bonding with electrode components is confirmed through electrochemical testing and post-mortem analysis. These results show that precise control of polymer architecture-particularly the interplay between side-chain length and interval-enables significant performance improvement, offering a rational strategy for designing durable, high-efficiency LIB binders.