Graphite – natural or synthetic – is the most dominant active material used for LIB anodes [1] . Natural graphite, however, is considered a critical material within the EU [2] , while synthetic graphite is obtained from coke [3] – a carbon precursor produced from coal or petroleum. Therefore, efficient recycling and reuse of graphite are essential towards sustainability and resource preservation [4] .
Herein, we report a novel and highly efficient process to recover high-quality graphite from spent LIBs. Following a comprehensive physicochemical characterization of the materials obtained, we conducted an extensive electrochemical characterization in half-cells and graphite‖NMC 532 full-cells and compared the results with the data obtained for half-cells and full-cells using pristine commercial graphite. In half-cells, the recycled graphite shows remarkably high reversible specific capacities (e.g., 350 mAh g ⁻ ¹ at C/20) and very stable cycling for several hundred cycles at 1C. The graphite‖NMC 532 full-cells also show excellent cycling stability, with a capacity retention of 80% after about 1,000 cycles. Particularly, the comparison with the pristine graphite comprising full-cells reveals very comparable performance, highlighting the great promise of recycled and reused graphite as a pivotal step towards truly sustainable LIBs and the great goal of a circular economy.
References
[1] J. Asenbauer, T. Eisenmann, M. Kuenzel, A. Kazzazi, Z. Chen, and D. Bresser, “The success story of graphite as a lithium-ion anode material – fundamentals, remaining challenges, and recent developments including silicon (oxide) composites,” Sustain. Energy Fuels , 2020.
[2] Comisión Europea, European Commission, Report on Critical Raw Materials and the Circular Economy, 2018 . 2018.
[3] S. Richard, W. Ralf, H. Gerhard, P. Tobias, and W. Martin, “Performance and cost of materials for lithium-based rechargeable automotive batteries,” Nat. Energy , vol. 3, no. Li, pp. 267–278, 2018.
[4] A. Vanderbruggen, E. Gugala, R. Blannin, K. Bachmann, R. Serna-Guerrero, and M. Rudolph, “Automated mineralogy as a novel approach for the compositional and textural characterization of spent lithium-ion batteries,” Miner. Eng. , vol. 169, p. 106924, 2021.