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. In conclusion, 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.. Authors: Yao, Zeyi [Worcester Polytechnic Institute, MA (United States)]; Ma, Xiaotu [Worcester Polytechnic Institute, MA (United States)] (ORCID:0000000325276313); Wang, Rui [Worcester Polytechnic Institute, MA (United States)]; Hou, Jiahui [Worcester Polytechnic Institute, MA (United States)] (ORCID:0000000211191880); Fu, Jinzhao [Worcester Polytechnic Institute, MA (United States)]. DOE Contract: AC02-06CH11357. Subjects: 25 ENERGY STORAGE; Economically and environmentally feasible; Graphite recycling and recovery; Li-ion full batteries; Scalable reactions; Surface modification