Mechanochemically Boosting Additive for Robust Si/C Anodes in High‐Energy‐Density Li‐Ion Batteries

Silicon (Si) is regarded as one of the most promising anode materials for Li‐ion batteries (LIBs) owing to its high specific capacity of 3579 mAh g –1 and low redox potential. However, large volume changes in Si during lithiation/delithiation cycles lead to microcrack formation in the electrode and rupture of the solid electrolyte interphase (SEI) layer, resulting in poor cycling stability. In this regard, Si/carbon (Si/C) composites have been widely explored to mitigate the volume changes in Si and increase the Li‐ion kinetics. However, the mechanochemically unstable SEI layer is still challenging for the development of high‐energy‐density Si/C anodes. In this study, polyvinylpyrrolidone (PVP) is introduced as a mechanochemically boosting electrode additive (MBEA) to enhance the chemical and mechanical stability as well as the electrochemical performance of Si/C composite anodes in LIBs. PVP can stabilize the anode interface by forming a robust inorganic‐rich SEI layer, which improves the Li‐ion kinetics owing to its chemical stability and mechanical integrity. Furthermore, PVP on the surface of Si/C composite anodes enhances the binding affinity, including the adhesion and cohesion properties of the active materials. In these regards, the Si/C anodes with MBEA (Si/C‐MBEA) exhibit excellent electrochemical performance with alleviated volume changes compared with the pristine Si/C anode. This study presents a facile and practical approach for the development of high‐performance Si‐based anodes for next‐generation LIBs.