Dual‐Layer Protected Silicon Anode With In Situ Converted MnSiO ₃ Interlayer and Carbon Shell for Lithium‐Ion Batteries

ABSTRACT

As promising high‐energy density anodes for lithium‐ion batteries, the Si electrodes face critical challenges from severe volume expansion and poor electrical conductivity. Herein, we report a dual‐layer protective structure (Si@MnSiO ₃ @C) constructed through an in‐situ conversion reaction followed by chemical vapor deposition carbon coating. The inner MnSiO ₃ layer is derived from the native SiO ₂ layer on Si, forming robust Si─O─Mn covalent bonds that ensure strong interfacial adhesion. The outer carbon layer provides a conductive network and additional structural confinement. This architecture effectively buffers volume expansion, enhances electron transport, and facilitates Li ⁺ diffusion kinetics. As a result, the Si@MnSiO ₃ @C composite delivers a high initial Coulombic efficiency of 80.1%, retains 86.1% of its capacity after 100 cycles at 0.5 A g ⁻¹ , and maintains a specific capacity of 1334 mA h g ⁻¹ after 600 cycles at 1 A g ⁻¹ , demonstrating excellent cycling stability and rate performance. This work presents a promising strategy for designing high‐performance Si‐based anodes through interfacial engineering.