One-Pot Construction of Core-Shell MnO/SiOx@NC Composites for High-Performance SiOx Anodes via Synergistic Interfacial Engineering.

Non-stoichiometric silicon oxide (SiOx) 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/SiOx@NC composite, wherein a nitrogen-doped carbon (NC) layer and MnO nanoparticles are simultaneously formed on SiOx through a single heat treatment. The strongly coupled MnO-NC-SiOx 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/SiOx@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 SiOx anodes.