Mechanically Robust and Interface-Stable pSi@GO–CNTs@C Anode via Multi-Level Confinement for Long-Cycling Lithium-Ion Batteries

Silicon anodes suffer from severe volume expansion (>300%) and interfacial instability, limiting their practical deployment in lithium-ion batteries (LIBs). Here, we propose a multilevel synergistic confinement strategy by constructing a hierarchical pSi@GO–CNTs@C composite. Porous silicon (pSi) synthesized via Mg2Si template etching provides intrinsic volume buffering. Electrostatic self-assembly of surface-functionalized pSi with graphene oxide (GO) and carbon nanotubes (CNTs) forms an interpenetrating 3D conductive network, enhancing electron/ion transport and mechanical integrity. A conformal carbon layer deposited via chemical vapor deposition (CVD) further isolates pSi from electrolyte, suppressing parasitic reactions and cooperatively confining volume changes. The optimized anode delivers exceptional cycling stability: >1000 mAh g–1 after 100 cycles at 0.1 A g–1 and 221 mAh g–1 after 1000 cycles at 5 A g–1. This work establishes a synergistic design paradigm addressing ionic/electronic transport, mechanical degradation, and interfacial instability simultaneously.