Chemically Coupled Multifunctional Binder Networks Enable Stable and Safe Microscale Silicon Anodes

ABSTRACT Silicon is a promising anode material for high‐energy‐density lithium‐ion batteries due to its ultrahigh theoretical capacity; however, its practical applications are largely impeded by severe capacity fading induced by the substantial volume changes during the lithiation and delithiation process. Here, we report a flame‐retardant polymeric binder with high stretchability that significantly enhances electrochemical performance and thermal safety of microscale silicon anodes. The multifunctional binder integrates rigid poly(acrylic acid) (PAA) as a mechanically robust framework and adenosine triphosphate (ATP) as active flame‐retardant segments, with the two components chemically cross‐linked via amidation. The resulting µSi/ATP‐PAA electrode exhibits a high initial Coulombic efficiency of 89.33% and excellent long‐term cycling stability, retaining a high specific capacity of 1427 mAh g −1 after 500 cycles at 1.2 A g −1 . Moreover, the phosphorus‐rich ATP moieties significantly improve the thermal safety of silicon‐based electrodes. This work provides a simple and practical strategy to design advanced binders for Si‐based anodes that combine high energy density with enhanced safety for next‐generation lithium‐ion batteries.