Multiscale Carbon‐Integrated Silicon Anode for Stable Cycling Under Practical Lithium‐Ion Battery Conditions

Abstract Silicon‐based anodes offer exceptional energy density but are limited by severe volume changes and poor electrical conductivity, hindering their commercial integration. Herein, a silicon/carbon composite is designed for seamless incorporation into conventional graphite anodes, addressing the industry's focus on boosting practical energy density. This composite is obtained by simple, scalable vibratory milling of industrial waste silicon with functionally distinct carbon materials, meeting stringent requirements for both performance and cost. This multiscale carbon structuring mitigates silicon delamination, ensures continuous electronic pathways during volume fluctuations, and stabilizes the electrode–electrolyte interface. Detailed post‐mortem analyses confirm that this hierarchical carbon network effectively suppresses silicon extrusion—accompanied by significant morphological changes—a common failure mode. When implemented as a ≈17.5 wt.% additive into graphite electrodes, the composite achieves an industrially relevant target capacity of 500 mAh g −1 . It delivers outstanding performance under commercial‐level metrics, including a high areal capacity of 3 mAh cm −2 , electrode density of 1.6 g cm −3 , and active material ratio of 96.9 wt.%. In full‐cell configurations paired with a LiNi 0.6 Co 0.2 Mn 0.2 O 2 (NCM622) cathode, the system retains ≈78% capacity after 500 cycles, demonstrating its viability for real‐world applications. These results highlight the critical role of hierarchical carbon design for next‐generation lithium‐ion batteries.