The Polymer Society of Korea

Abstract

With the growing demand for high-performance lithium-ion batteries, the development of electrode materials with both high energy density and long cycle life is essential. Silicon is a promising anode material because of its much higher theoretical capacity than graphite, but its large volume change during cycling causes structural instability and rapid performance degradation.
In this study, water-soluble polyimide (W-PI) was applied as a binder for silicon anodes. The carboxyl groups (-COOH) in W-PI form strong chemical bonds with silicon nanoparticles, providing excellent interfacial adhesion, while the flexibility of the polymer chain accommodates repeated volume changes. As a result, the silicon anode using W-PI showed improved initial capacity, enhanced cycle stability, and stable charge/discharge performance compared to conventional binders.