Discovery of Optimal Interplay between Grafting Ratio and Side-Chain Interval in Adhesive Polymer Binders for Lithium-Ion Batteries

Polymer binders play a critical role in ensuring adhesion and mechanical stability in lithium-ion battery electrodes. Here, we systematically explore the architectural influence of poly(vinylidene fluoride)-graft-poly(acrylic acid) (PVDFA) binders synthesized via atom transfer radical polymerization. By tuning the grafting ratio and side-chain interval, we identify an optimal structure that maximizes adhesion and cycling stability. The optimized binder (22 mol % grafting, ∼300 interval) outperforms conventional PVDF in electrochemical performance. This study highlights the important role of fine-tuning polymer architecture in governing interfacial and mechanical properties and provides fundamental insights for the rational design of advanced adhesive binders for high-performance lithium-ion batteries.