A multi-analytical methodology for the characterization of industrial samples of spent Ni-MH battery powders. (December 2020)

• Record Type: Journal Article
• Authors: Zielinski, Margot; Cassayre, Laurent; Floquet, Pascal; Macouin, Mélina; Destrac, Philippe; Coppey, Nicolas; Foulet, Cédric; Biscans, Béatrice
• Is Part Of: Waste management. Volume 118(2020)
• Page Start: 677
• Page End: 687
• Publication Date: 2020-12
• Subjects: Ni-MH battery recycling -- Black Mass characterization -- Elemental mapping -- Clustering algorithms -- Magnetic susceptibility -- Thermal deactivation; Hazardous wastes -- Periodicals; Refuse and refuse disposal -- Periodicals; 363.728
• DOI: 10.1016/j.wasman.2020.09.017
• Languages: English
• ISSNs: 0956-053X

Abstract

Graphical abstract: Highlights: Methodology for characterizing industrial powders from spent Ni-MH batteries. Adaptation of mineralogical techniques to urban mining problematics. Statistical treatment of elemental maps using automated clustering algorithms. The proportions and compositions of three categories of particles were determined.; Importance of battery thermal deactivation and sieving on powder composition. Abstract: A multi-analytical methodology is implemented to characterize several sieving fractions of industrial samples of Black Mass (BM) powders originating from the thermo-mechanical treatment of cylindrical and prismatic-type spent nickel metal-hydride (Ni-MH) batteries. Elemental analyses of 17 elements (including C and O) indicate that the elemental composition of the powders (greater than93 %wt) does not depend on the battery type nor on the sieving fraction. XRD analyses evidence several phases (including Ni, NiO, CeO2 and C) but their quantification is not possible. Beyond these standard characterisations, magnetic susceptibility measurements demonstrate that the amount of metallic nickel versus nickel oxide increases with the sieving fraction, and that powders from prismatic-type batteries contain twice as much metallic nickel than cylindrical ones. Thanks to statistical analysis (based on clustering algorithms) of an electron probe µ-analysis (EPMA) compositional map, the complete methodology allows us to propose a full phase distribution for the BM particles. Three types of particles are identified and quantified. They originate from the partial oxidation of the battery components (anode active mass, anode current collector, cathode active mass and cathode current collector). The whole picture highlights the joint importance of battery ageing mechanisms, thermal deactivation and BM sieving steps on powder composition.