The Polymer Society of Korea

Abstract

Silicon anodes suffer from electrode detachment due to volume expansion during charge-discharge cycles. To improve adhesion, PAA binders with COOH groups are employed, as they can form strong hydrogen bonds with silicon. PAA tends to aggregate due to intra-hydrogen bonding between its COOH groups. This reduces interfacial contact, leading to decreased battery performance. In this study, molecular dynamics simulations were conducted to investigate the structural behavior of PAA depending on the anions of lithium precursors and to examine its interactions with Li⁺. The radius of gyration analysis revealed that the LiOH-PAA system has high flexibility. Furthermore, the radial distribution function confirmed strong interactions between Li⁺ and COO^- groups in the LiOH-PAA system, suggesting their contribution to pre-lithiation in silicon anodes. This study provides insights into the design of polymer binders based on anion-specific effects for achieving high-performance silicon anodes.