Degradation Pathways of Silicon-Based Anodes in Lithium-Ion Batteries

초록

Silicon offers high theoretical capacity as an alternative to graphite, yet it undergoes much more severe degradation, resulting in substantially poorer cycle and calendar life. In this context, a mechanistic understanding of degradation pathways is essential for designing silicon-based anodes with performance comparable to graphite. In this review, we present a comprehensive overview of the degradation mechanisms governing silicon-based anodes. The mechanisms are organized around active materials degradation at the particle level, which is governed by both intrinsic factors of silicon and extrinsic factors. At the electrode scale, we discuss electrode integrity loss, which arises from the breakdown of mechanical and electrical continuity. In addition, we differentiate solid electrolyte interphase instability into mechanical and chemical degradation mechanisms to clarify how each contributes to performance decay. We further describe lithium trapping as an additional source of irreversible capacity loss. Finally, we address crosstalk degradation that arises when silicon is used together with graphite, driven by mechanical and thermodynamic interactions between the two materials. This review provides an integrated understanding of the degradation pathways of silicon-based anodes, offering insights that can guide material design and improve the performance of lithium-ion batteries.

키워드