Recycled graphite enabled superior performance for lithium ion batteries

Recycling graphite attracts growing attention since cumulative amount of spent Li-ion batteries and the shortage of graphite supply chain. Although various recycling methods have been reported, the recycled graphite cannot reach the strict commercial standards of purity, scalability, efficiency, and capacity, preventing it from battery manufacturing. Herein, the important roles of defects and functional groups on the graphite surface are deeply studied, and a closed-loop graphite recycling process with the surface recovery and modification for the graphite from the end-of-life batteries is demonstrated. The recovered graphite delivers a purity of over 99.9 % and an average initial coulombic efficiency of 91.5 %. Compared with commercial graphite in industrial standard battery testing parameters, full cells with recovered graphite possess enhanced rate reversibility, doubled cycle life, over 10 % higher capacity along with half anode material cost. These impressive results not only underscore the transformative potential of surface reconstruction and modification in graphite recycling, but also present economic feasibility and sustainable pathway for significantly improving battery performance and addressing global resource challenges via integration with the hydrometallurgical recycling process. A scalable closed-loop graphite recycling method is developed to overcome the limitation of raw materials and waste utilization. The economically feasible recycled graphite delivers high purity and high coulombic efficiency, along with a better rate performance and higher capacity compared with commercial graphite in standard full-cell tests, thus perfecting the whole lithium-ion battery recycling process. [Display omitted] •Industrial waste graphite is fully recovered by a novel scalable process.•The recovered graphite delivers a comparable capacity and better rate performance.•The functions of surface defects and dislocations are deeply studied.•The full batteries deliver 85 % longer cycle life.•The environmental and economic feasibility of the recycling process are verified.