Enhanced lithium-ion storage and diffusivity in regenerated graphite anodes with upcycled N-doped reduced graphene oxide from spent lithium-ion batteries Chanmo Park

The growing demand for lithium-ion batteries (LIBs) and their subsequent disposal is a serious environmental concern, requiring effective recycling and upcycling strategies. In this study, graphite residues from used LIBs were regenerated through a water washing process and thermal sintering process to effectively remove impurities and restore the structure of graphite. Furthermore, N-doped reduced graphene oxide, upcycled from washed graphite (W-NrGO), was added as an additive to enhance the electrochemical properties of the regenerated graphite (RG). The RG/W-NrGO anode material exhibited superior lithium-ion storage capacity and diffusion kinetics, with the synergistic effects of NrGO providing additional storage sites and facilitating lithium-ion transport. Electrochemical evaluations demonstrated that RG/W-NrGO achieved an average discharge capacity of 543.78 mAh/g over 100 cycles, approximately 1.5 times greater than commercial graphite (372 mAh/g). The lithium-ion diffusivity of RG/W-NrGO (4.17 ˟ 10-9 cm2/s) was improved by 3.2 times compared to RG (1.30 ˟ 10-9 cm2/s), highlighting the role of NrGO in enhancing transport kinetics. This study demonstrates the potential of graphite regeneration and upcycling for high-performance anode materials, offering sustainable approaches to LIB recycling and advancements in energy storage technology.Maste