Revisiting the core problem impeding the commercialization of silicon-based lithium-ion batteries

To meet the growing demand for high-energy-density lithium-ion batteries (LIBs), silicon (Si) anodes have gained attention as a promising material for next-generation anodes owing to their ultrahigh gravimetric capacity. Nevertheless, the Si anode faces significant challenges, particularly severe volume expansion during cycling, which leads to rapid capacity degradation and greatly hinders its commercialization potential. Although extensive research has focused on mitigating volume changes and constructing stable solid-electrolyte interphases on Si-based anodes, a crucial factor for practical application, namely the volumetric capacity, has been often overlooked. For Si-based anodes to replace conventional graphite anodes, their volumetric capacity must be thoroughly evaluated. Key factors determining the volumetric capacity include gravimetric capacity, active material mass ratio, initial Coulombic efficiency, electrode swelling ratio, and the negative-to-positive capacity ratio. This paper systematically analyzes, discusses, and summarizes each of these factors in detail. Common issues with existing strategies are identified, and future research directions concerning the commercialization of Si-based anodes are outlined. This study provides a systematic and novel perspective on effectively modifying and designing Si-based anodes, aiming to promote the volumetric capacity toward the large-scale industrialization of next-generation LIBs.