Ionophilic Amide‐Linked Planar π ‐Conjugated Polymer Armored Si Microparticles for Stable Anode and F‐Rich Solid Electrolyte Interphase Formation in Lithium‐Ion Batteries

Silicon is the most promising high‐capacity anode material for high‐energy lithium‐ion batteries (LIBs). However, its practical application is hindered by severe volume expansion and continuous solid electrolyte interphase formation during cycling, leading to rapid capacity decay and short cycle life. In this study, amide bond‐linked π ‐conjugated polymer‐coated silicon microparticles (ACP@Si MP) are developed. The robust amide‐bond and stacked π ‐conjugated polymer planes dissipate the stress from volume expansion, suppressing pulverization and maintaining the structural integrity of the anode. Bipolar amide bond from the resonance effect provides cation and anion affinity, facilitating Li + transfer and regulating F‐rich solid electrolyte interphase (SEI) formation. This maintains the reversibility of the Si anode and minimizes the accumulated dead Si during cycling by improving electrochemical kinetics through the formation of a conductive SEI layer. The ACP@Si MP anode exhibits a high reversible capacity (3289 mAh g −1 ), high initial Coulombic efficiency (87%), low decay rate of 0.072% per cycle, and a high reversible capacity (1114 mAh g −1 ) at high current density (6 A g −1 ). This study highlights the potential of ionophilic conjugated polymer networks to obtain a robust protective layer, facile ion transfer, and regulated F‐rich SEI, paving the way for durable Si‐based anodes in next‐generation LIBs.