Direct Multielement Analysis of Polydisperse Microparticles by Classification-Single-Particle ICP-OES in the Field of Lithium-Ion Battery Electrode Materials

Abstract

The chemical and structural complexity of lithiumion battery electrodes and their constituting materials requires comprehensive characterization techniques to reveal degradation phenomena at the mesoscale. For the first time, application of single-particle inductively coupled plasma-optical emission spectroscopy enables the investigation of the chemomechanical interplay on the particle level of lithium transition-metal oxide [e.g., Li(Ni 1/3 Co 1/3 Mn 1/3 )O 2 ] cathode materials. The sampleinherent polydisperse size distribution of particles ranging up to 10 μm was effectively restricted with the use of a custom-made gravitational-counter-flow classifier to facilitate complete particle vaporization and excitation. After classification, the particles were transported directly to the plasma by means of an argon flow to prevent chemical alterations in aqueous media due to potentially occurring Li + −H + exchange reactions. The size-separated particles were monitored online by flow cell particle analysis (FPA). The influence of different gas flow settings and plasma parameters on the peak emission intensity of Li and Mn was evaluated. A particle size detection limit of ∼0.5 μm was estimated based on the 3σ criterion of the baselines and the measured peak intensities for Li and Mn considering the particle size distribution as obtained by FPA. The corresponding analyte masses at the detection limits were ∼30 and ∼180 fg for Li and Mn, respectively. Furthermore, an approach for a matrix-matched external calibration with electrochemically delithiated lithium transition-metal oxides is presented.

Comprehensive Characterization of Shredded Lithium‐Ion Battery Recycling Material

“…It has to been stated, that mixtures of NCM or additional LiNi x Co y AlO 2 (NCA) stoichiometries could make this analysis more complicated. If the ICP‐OES/MS results hint at a mixture of NCM and/or NCA materials, for example single particle investigations, recently introduced by Kröger et al., [43] could give further insights regarding mixed stoichiometries and varying active materials.…”

State-of-charge of individual active material particles in lithium ion batteries: a perspective of analytical techniques and their capabilities

“…Despite this limiting factor, larger particles can still be analyzed using CL-SP-ICP-OES if incomplete evaporation and excitation are accounted for by matrix-matched external calibration. 71 Moreover, the optical emission detection system could be exchanged for a mass spectrometer to reduce the dwell time and limits of detection. Especially time-of-flight (ToF) mass analyzers can be a promising option for single particle analysis as typical quadrupole mass analyzers are only able to monitor a single mass-to-charge ratio ( m/z ) during operation.…”

Atomic spectrometry update: review of advances in the analysis of metals, chemicals and materials

“…Two papers by Kroger et al used single particle ICP-OES measurements to determine microparticles in lithium ion batteries. 228,229 In the rst, a lithium transition metal oxide mixture Li(Ni 1/3 Co 1/3 Mn 1/3 )O 2 cathode material (known as NCM111) was analysed. The powder (200 mg) was injected into the top of an s-shaped gravitational counter ow classier that had been made in house and argon introduced at the bottom.…”