Interfacial engineering of porous SiOx@C composite anodes toward high-performance lithium-ion batteries

SiOx@C anodes have been regarded as one of the most attractive candidates for next-generation high-capacity lithium-ion batteries (LIBs). However, the uneven thickness and lack of continuity in the carbon coating have led to a decrease in capacity, lifespan, and coulombic efficiency. Thus, there is a pressing need to address the atomic-level construction of the Si/C interface. In this study, we present a simple interfacial engineering approach to achieve an in-situ compact carbon layer on porous SiOx@C (pSiOx@C) anodes through low-temperature zinc thermal reduction. Following prelithiation, the pSiOx@C anode demonstrates excellent performance, including a high initial Coulombic efficiency (93.4%), a reversible capacity exceeding 900 mAh/g, long-term cycling stability (1300 charge/discharge cycles at 0.3 A/g) and remarkable rate capability. Furthermore, when coupled with the LiCoO2 (LCO) cathode, the pSiOx@C//LCO full cell exhibits superior Li-ion storage performance, achieving a high reversible capacity of 147 mAh/g at 0.2 A/g. This work provides valuable insights into the design of SiOx-based anode materials for high-energy–density LIBs.