Interface-confined silicon anode enabled by covalent anchoring and conductive network for stable and fast Lithium...

Achieving fast and durable lithium storage in silicon anodes remains a major challenge due to severe volume fluctuations and unstable solid-electrolyte interfaces (SEI). Herein, an interface-confined Si-GO@CNT composite anode is developed by constructing multi-point Si-O-C bonds between silicon (Si) nanoparticles and graphene oxide (GO) sheets, reinforced by a percolated carbon nanotube (CNT) network. This architecture enables synergistic interfacial confinement and continuous charge transport: covalent Si-O-C anchoring mitigates pulverization and stabilizes the SEI, while the CNT network ensures electron conduction under mechanical stress. Electrochemical and theoretical analyses confirm enhanced Li⁺ diffusivity, reduced migration barriers, and improved interfacial stability. As a result, the Si-GO@CNT electrode delivers a high capacity of 1223.4 mAh g^-1 after 100 cycles and retains 965.9 mAh g^-1 after 200 cycles at 1 A g^-1, along with a rate capacity of 753 mAh g^-1 at 3C. This work offers a scalable interfacial engineering strategy toward high-performance silicon anodes without external mechanical confinement.