The Polymer Society of Korea

Abstract

Li-ion batteries have emerged as the most important energy supply devices. However, graphite electrodes do not satisfy the performance demands of modern high-performance batteries, because graphite suffers from low capacity, high cost and limited power output. To address these demands, many studies on silicon anode are being conducted. In order to commercialize a silicon anode, it is important to suppress the drastic volume expansion of silicon anode.
In this study, polyurethane (PU) binders with different crosslinking densities were synthesized for the silicon anode. The urethane group of polyurethane forms a hydrogen bond with the silanol group on the silicon outside, enabling strong interaction. The electrochemical performance of the battery was evaluated according to the crosslinking density of PU. High crosslinking density effectively suppressed the extreme volume expansion of silicon particle, lowered interfacial resistance, and showed high-capacity retention rate.