One‐Pot Construction of Core–Shell MnO/SiO x @NC Composites for High‐Performance SiO x Anodes via Synergistic Interfacial Engineering

ABSTRACT Non‐stoichiometric silicon oxide (SiO x ) is a promising high‐capacity anode material for lithium‐ion batteries but suffers from low initial Coulombic efficiency (ICE) and severe volume expansion. Herein, a one‐pot polydopamine (PDA)‐assisted strategy is developed to construct a core–shell MnO/SiO x @NC composite, wherein a nitrogen‐doped carbon (NC) layer and MnO nanoparticles are simultaneously formed on SiO x through a single heat treatment. The strongly coupled MnO–NC–SiO x interface modulates the local electronic structure and increases the pyridinic N fraction, while the MnO phase weakens excessively strong Li binding, reducing irreversible Li consumption. The continuous NC layer buffers volume changes and facilitates electron/ion transport. Consequently, the MnO/SiO x @NC anode achieves a high ICE of 85.02%, excellent rate capability (91.3% capacity recovery), and superior cycling stability (83.0% retention after 365 cycles at 0.5 A g −1 ). This work provides a simple and effective strategy to overcome the intrinsic limitations of SiO x anodes.