Scalable synthesis of a freeze-dried Si@rGONRs composite anode with prelithiation-induced SEI stabilization for high-performance Li-ion batteries

초록

Silicon is a highly attractive anode material for lithium-ion batteries because of its exceptional theoretical capacity; however, its application is limited by extreme volume expansion and unstable solid-electrolyte interphase (SEI) formation. In this study, a robust composite anode was developed by embedding silicon nanoparticles within a reduced graphene oxide nanoribbon (rGONRs) matrix via the freeze-drying technique and enhanced by applying a direct contact prelithiation strategy. The resulting Si@rGONRs composite exhibited a flexible, conductive core-shell structure with strong Si-C and Si-O-C interfacial bonding, enabling both mechanical resilience and fast charge transport. Prelithiation boosts the initial Coulombic efficiency to over 100 %, compensating for the lithium loss and stabilizing the SEI. The anode delivers a high reversible capacity of 1600 mAh g- 1 at 200 mA g- 1 and retains 1261 mAh g- 1 at 2000 mA g- 1, with outstanding cycling stability (95.5 % retention after 400 cycles at 500 mA g-1). Post-mortem analysis revealed only a 59 % thickness expansion, which is far lower than the 142 % observed in the pure Si anode. This study demonstrates a scalable strategy to integrate structural confinement and prelithiation for long-life, high-capacity Si-based anodes, offering a promising direction for next-generation lithium-ion batteries.

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