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Recycled Graphite for Sustainable Lithium-Ion Batteries

Wednesday, 1 June 2022: 16:20
West Meeting Room 210 (Vancouver Convention Center)
M. Olutogun (Helmholtz Institute Ulm (HIU), Karlsruhe Institute of Technology (KIT)), A. Vanderbruggen (Aalto University, School of Chemical Engineering, Helmholtz Zentrum Dresden-Rossendorf (HZDR)), M. Rudolph (Helmholtz Institute Freiberg for Resource Technology (HIF), Helmholtz Zentrum Dresden-Rossendorf (HZDR)), S. Passerini (Helmholtz Institute Ulm (HIU), Karlsruhe Institute of Technology (KIT)), and D. Bresser (Karlsruhe Institute of Technology (KIT))
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‖NMC532 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 g1 at C/20) and very stable cycling for several hundred cycles at 1C. The graphite‖NMC532 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.