Polymer Coating Enabling a Durable Conductive Network for Si-Based Lithium-Ion Batteries

Silicon nanoparticles (SiNPs) have become a promising class of high-capacity silicon-based anodes. However, their large surface area intensifies severe interfacial side reactions, which impair kinetic performance. In this study, a uniform allyltrimethoxysilane-derived polymer (AP) coating is applied to SiNPs, enhancing the durability of the conductive network by strengthening triphasic contact integrity among SiNPs, conductive additives, and binders. This effectively mitigates electrical contact failure caused by volume fluctuations during cycling. The coating also improves the mechanical integrity of the entire electrode, while the robust solid electrolyte interphase (SEI) layer it induces prevents electrolyte penetration over long cycling. The optimized Si@AP anode exhibits an impressive reversible capacity of 1300 mAh g^-1 after 200 cycles and delivers a rate capacity of 842 mAh g^-1 at 5 C. This work underscores the significant potential of in situ polymer coatings for enhancing the mechanical and electrochemical performance of Si-based anodes.