Binder‐Induced Interfacial Engineering of a Dual‐Layered SEI for Durable Silicon Anodes Over a Wide Temperature Range

ABSTRACT

Silicon is a promising next‐generation anode for high‐energy‐density lithium‐ion batteries, yet its practical application is hindered by severe volume variation, structural degradation, and unstable solid‐electrolyte interphase (SEI). Herein, a novel multifunctional binder PNTA, composed of polyacrylic acid and nitrilotriacetic acid, is designed to enhance both the structural and interfacial stability of silicon anodes. The robust hydrogen‐bonding network of PNTA preserves structure integrity of the electrode during cycling. Meanwhile, the binder strongly impacts the electrode‐electrolyte interfacial properties by tuning local microenvironment (EC, DEC, and PF ₆ ⁻ concentration), facilitating Li ⁺ desolvation and regulating preferential reduction, thus inducing a unique dual‐layer SEI enriched with N‐containing and LiF components. This SEI demonstrates exceptional stability, combining energy‐dissipative characteristics with rapid Li ⁺ conduction, which ensures long‐term cyclability and wide‐temperature operation. As envisioned, the Si@PNTA anode exhibits outstanding cycling stability (>984 mAh g ⁻¹ after 1000 cycles at 2 A g ⁻¹ ) and superb performance from −15°C to 120°C. Moreover, this novel binder is well adapted to high‐loading SiO _x and Si/C anodes, achieving areal capacities of 4.98 and 3.74 mAh cm ⁻² , respectively. By exploring the fundamental mechanisms of interfacial tailoring, this work offers a new pathway to promote the overall properties of silicon‐based anodes via innovative multifunctional binders.