The Si surface coating by carbon is an appealing strategy to improve both theelectronic conductivity and to stabilize the solid electrolyte interphase (SEI).In the present study, the electrochemical performance comparison of threenanocrystalline silicon‐based electrodes confirms the advantage brought bythe carbon presence either as coating or in a composite, to improve theirperformance in Li‐ion batteries (LIBs). To rationalize this behavior, a fullstudy of the electrode/electrolyte interface was achieved through the analysisof the cumulated relative irreversible capacity and the impedance and X‐rayphotoelectron spectroscopies measurements. The study highlighted that thecarbon coating leads to more efficient and less resistive SEI than that formedon silicon or on the native oxide surface. The pitch carbon matrix offers thesame advantages and avoids moreover the isolation of particles. The control ofthe Si/electrolyte interface has a crucial role in the performance of Si‐basedelectrodes as negative electrodes for LIB.