A simple methodology for the quantification of graphite in end-of-life lithium-ion batteries using thermogravimetric analysis

Luis Arturo Gomez-Moreno; Anna Klemettinen; Rodrigo Serna-Guerrero

doi:10.1016/j.isci.2023.107782

A simple methodology for the quantification of graphite in end-of-life lithium-ion batteries using thermogravimetric analysis

iScience. 2023 Aug 29;26(10):107782. doi: 10.1016/j.isci.2023.107782. eCollection 2023 Oct 20.

Authors

Luis Arturo Gomez-Moreno¹, Anna Klemettinen¹, Rodrigo Serna-Guerrero¹

Affiliation

¹ Department of Chemical and Metallurgical Engineering, School of Chemical Engineering, Aalto University, P.O. Box 16200, Espoo, Aalto 0076, Finland.

Abstract

A new method based on thermogravimetric analysis was developed to measure the graphite content in battery material mixture. This approach exploits the thermochemical reduction of cathodic Li-transition metal oxides with anodic graphite at elevated temperatures under an inert atmosphere. Using known composition artificial mixtures, a linear correlation between cathode mass loss and sample graphite content was observed. The method was validated using industrial black mass samples and characterized traditionally to estimate and rationalize potential error sources. Thermal degradation profiles of industrial battery waste reflected those in the artificial system, demonstrating its applicability. This work also demonstrates that thermogravimetric degradation profiles can distinguish between a cathode consisting of single or multiple Li-metal oxides. Although accuracy depends on active component mixture content and impurities, it is demonstrated that the method is useful for a fast graphite content estimation. Unlike other graphite characterization techniques, the method proposed is simple and inexpensive.

Keywords: Analytical method in materials science; Electrochemical energy storage.