Surface engineering enables the upcycling of spent graphite from retired lithium-ion batteries

The lithium-ions batteries (LIBs) have been widely employed in electric vehicles (EVs) and energy storage systems, with a generation of huge quantity of retired LIBs enriched with valuable metals and graphite resources. While it is still challenged with imbalance between extensive energy input and degraded electrochemical performances during the recycling of graphite. Herein, we proposed an energy-saving approach combined with Advanced Oxidation Process (AOP) purification, Li_1.3Al_0.3Ti_1.7(PO₄)₃ (LATP) coating and thermodynamics reconstruction towards the upcycling of graphite. Firstly, impurity lithium compounds with oxygen-containing functional group were effectively removed by AOP. Then, the morphology and layered structure of graphite were successfully restored through thermal treatment. Finally, the regenerated graphite was coated using LATP via deposition, constructing the continuous conduction pathways for Li⁺ which can be confirmed by enhanced diffusion coefficients measured through Galvanostatic Intermittent Titration Technique (GITT). Upcycled coated graphite delivers a reversible capacity of 436.5 mAh·g^-1 at 0.1C with full-cell excellent capacity retention of 88.90% after 180 cycles via long-term cycling test. This work offers an efficient and sustainable upcycling approach towards conversion of spent graphite with restored structure and superior electrochemical performances, providing a promising strategy for spent LIBs recycling.