Ultrastable Monodisperse Resin‐Based Spherical Si─C Materials With Micropore Confined Growth of Silicon Nanoclusters for Lithium‐Ion Battery Anodes

Abstract Monodisperse spherical silicon‐carbon (Si/ASC) composites are developed as high‐performance anodes for lithium‐ion batteries (LIBs). The composites are synthesized by combining phenolic resin‐derived carbon spheres with chemical vapor deposition (CVD) to uniformly deposit silicon within the carbon matrix. The micropore nanoconfinement effectively mitigates silicon's volume expansion during cycling, enhancing electrochemical stability. The Si/ASC composite retains 93.3% of its initial capacity after 800 cycles in half‐cell testing and 46.7% after 500 cycles in full‐cell testing. In situ volume expansion analysis shows minimal expansion, confirming the stability of the composite. These findings highlight the potential of Si/ASC as a promising anode material for high‐energy‐density, long‐cycle‐life LIBs.