Interfacial Anchoring Effect Enables a Stable and High-Areal-Capacity Silicon/Carbon Composite Anode

Silicon (Si) has been widely accepted as a promising anode material owing to its high theoretical capacity (3590 mAh g –1 ) and abundance. Nevertheless, its practical application in next-generation batteries has long been hindered by several inherent challenges, including an unstable solid-electrolyte interphase (SEI), large volume changes, and low electrical conductivity. Herein, a facile and effective chemical route is proposed to construct a functional organic molecule that could constrain the framework and tune the interfacial properties of Si/C electrodes. Superior electrochemical performance with high anode material loading (∼8.0 mg cm –2 ) and high areal capacity (above 3.0 mAh cm –2 ) is achieved for the Si/C anode in terms of excellent cycling stability. A unique interfacial anchoring mechanism is found that plays a major role in effectively alleviating the huge volume expansion and maintaining the integrity of the Si/C electrode. Moreover, an investigation of the surface chemistry confirms that the constructed molecule can improve the stability of the SEI by promoting the formation of a LiF-rich interphase. Our findings provide deep insights into the design of high-performance Si/C anodes for practical applications in next-generation batteries.