Stereoactive Metallic Vanadium Oxide Barriers to Boost Silicon‐Based Lithium‐Ion Storage

Abstract Despite the intensive efforts devoted to confining silicon (Si)‐based materials with heteromatrices for high‐energy‐density lithium‐ion batteries, addressing practical issues with rationally incorporated stereoactive matrix is still a significant challenge. This study presents an electrochemical‐active, metallic matrix for boosting Si‐based lithium‐ion storage. By employing a straightforward strategy involving mechanical ball‐milling and controllable phase transformation, spatially confined Si‐based composites enabled by metallic vanadium oxide (VO_0.9) barriers can be readily achieved. The scalable interface engineering allows for expanded transportation channels and maintained structural integrity, which can be well established in both SiO_x and Si cases. Endowed with promoted electron conduction as well as fast lithium‐ion diffusion, the optimal Si‐based composite electrodes demonstrate remarkable lithium storage performance, that is, an initial Coulombic efficiency of 81%, and a high specific capacity of 1249 mAh g⁻¹ at 500 mA g⁻¹ after 100 cycles. Notably, full cells coupled with a commercial LiCoO₂ cathode are demonstrated, affording impressive specific energy of 440 Wh kg⁻¹ at high mass loading. This work provides a cost‐effective approach to promoting the practical application of Si‐based anodes, which also holds promise for extension towards energy‐related applications and beyond.