ScholarWorks@성균관대학교

초록

Silicon anodes in Li-ion batteries suffer from severe mechanical degradation during repeated lithiationdelithiation cycling, highlighting the critical role of binder-mediated mechanical stability. In this context, supramolecular binders based on reversible interactions offer stress dissipation and self-healing capabilities; however, their long-term retention of dynamic bonds under cyclic deformation remains poorly understood, as existing evaluations focus primarily on viscoelastic metrics or transient self-healing responses. Here, we introduce a rheological fatigue-analysis method for supramolecular binders using a multi-rest time sweep test adapted from established rheological fatigue protocols, enabling simultaneous quantification of thixotropy, dynamic bond recovery, irreversible damage accumulation, and fatigue endurance limits. As a model system, we employ a poly(acrylic acid) (PAA)-based supramolecular binder that incorporates p-phenylenediamine (pPD) as a dynamic crosslinker. Systematic variation of pPD content reveals a non-monotonic relationship between crosslinker concentration and dynamic-bond retention. In particular, the 10 mol% pPD formulation delivers the highest fatigue endurance and the most robust network recovery, which correlates directly with improved electrochemical cycling performance. Collectively, these results demonstrate that the durability of supramolecular binders is governed not merely by viscoelasticity, but by the persistence of reversible interactions under repeated strain, thereby establishing a mechanistic design criterion for developing high-stability Si anodes for Li-ion batteries.

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