Characterization and Thermal Treatment of the Black Mass from Spent Lithium-Ion Batteries

Abstract

Recycling lithium-ion batteries is crucial for the environment and the sustainability of primary resources. In this paper, we report on the characterization of two grades of black mass from spent lithium-ion batteries (with typical lithium–nickel–manganese–cobalt oxide cathode compositions) and their behavior during heating trials. This study paves the way for optimizing lithium-ion battery recycling processes by fully characterizing black mass samples before and after heating. A gas release under pyrolytic conditions was detected using a multicomponent mass spectrometer and included dimethyl carbonate, diethyl carbonate, oxygenated hydrocarbons, hydrocarbons, and other miscellaneous gases. This can be attributed to the evaporation of volatile organic compounds, conductive salt, organic polyvinylidene fluoride binder, and an organic separator such as polypropylene. Thermal treatment led to the partial decomposition of the binder into char and newly formed fluorine cuboids. The compaction of the cathode decreased, but the remaining binder limited recycling processes. By heating the black mass samples to 900 °C, the intensity of the X-ray diffraction graphitic carbon peak decreased, and the lithium metal oxides were reduced to their corresponding metals. The graphite in the black mass samples was structurally more disordered than natural graphite but became more ordered when heated.

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

“…In an inert atmosphere, a mass loss detected by TGA will thus be associated with the release of CO and CO 2 that is correlated to the graphite content. This idea is in direct contrast to previously published studies using TGA under flowing air, 34 , 35 , 36 where uncontrolled combustion reactions take place, making it difficult to correlate mass changes with the BM composition. To develop the novel approach hereby proposed, TGA-EGA results were performed on artificial mixtures of graphite and cathode materials, i.e., Li(Ni 0.33 Mn 0.33 Co 0.33 )O 2 (NMC) or LiCoO 2 (LCO) at known compositions to produce standardized correlation functions.…”

A Review of Lithium-Ion Battery Recycling: Technologies, Sustainability, and Open Issues

“…Emissions from technical processes can occur in two ways when recycling LIBs: reaction emissions and material losses. Reaction emissions are generated from chemical reactions during the process, such as thermochemical reactions [125]. Material losses, on the other hand, result from the release of components of the batteries during the recycling process.…”

Modelling Binder Degradation in the Thermal Treatment of Spent Lithium-Ion Batteries by Coupling Discrete Element Method and Isoconversional Kinetics

“…Moreover, two common thermal processes are used to degrade the binder, calcination and pyrolysis, and an overview of industrial recycling routes can be found in [14]. Pyrolysis is more effective than calcination in preventing undesired graphite decomposition due to the absence of oxygen in the atmosphere [6,[15][16][17][18], which is one particular reason for our focus on pyrolysis conditions in this work. In order to tailor the binder degradation during the thermal treatment of black mass, efficient computational methods are necessary to optimize future thermal treatment processes and adapt flexibly to changing feeds in the recycling route.…”