From Design to Application: Interface Engineering in Hierarchical Si/C Anodes for High‐Energy‐Density Batteries

Silicon anodes, renowned for their ultrahigh theoretical capacity, are pivotal for advancing next‐generation lithium‐ion and solid‐state batteries. However, their severe volume variation during cycling poses a fundamental challenge, leading to rapid electrochemical failure. This review systematically elucidates intrinsic mechanisms and design strategies for high‐performance silicon/carbon (Si/C) anodes via multi‐scale interface modulation, focusing on chemical vapor deposition (CVD)‐derived composites as a key model system. We explore the control of internal Si/C and electrode/electrolyte interfaces, while discussing complementary strategies such as intrinsic optimization (doping, alloying), architectural engineering (porous, yolk–shell structures), and electrode‐level regulation (binders, electrolytes). The discussion extends to pouch cells and solid‐state batteries, where interface stability is paramount. By establishing structure–interface–performance correlations, this work provides a holistic framework for transitioning high‐capacity silicon anodes from laboratory prototypes to commercial applications.