Elucidating the Synergistic Role of In Situ SiOX Shell and rGO Network in Stabilizing Si Anodes via Distribution of Relaxation Times Analysis

Si is a promising anode material for lithium‐ion batteries due to its high theoretical capacity, but its practical use is hindered by severe volume changes, unstable solid electrolyte interphase (SEI) formation, and poor intrinsic conductivity. To address these limitations, Si/SiOX/reduced graphene oxide (rGO) composites were synthesized, in which the in situ grown SiOX layer stabilizes interfacial reactions and the rGO network enhances electronic conductivity. Here, electrochemical impedance spectroscopy combined with distribution of relaxation times (DRT) analysis was employed to disentangle the overlapping contributions of the SEI, charge transfer, and diffusion. Importantly, the DRT analysis resolved the dynamic SEI responses, revealing that SiOX predominantly governs interfacial stability by mitigating volume change induced stress, while rGO ensures continuous electron percolation and suppresses excessive SEI growth. As a result, the composites demonstrated superior cycling stability and rate capability compared with pristine Si. This work provides mechanistic insights into how interfacial and conductive layers cooperatively govern resistance evolution in Si‐based electrodes and offers guidance for the rational design of high‐performance Si anodes.