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

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.