Reliably Analyzing Residual Material from Lithium-Ion Batteries

The recycling of lithium-ion batteries is rapidly gaining importance. The European Union mandates a recycling efficiency of 65% of the average weight of lithium-ion batteries. At the heart of the recycling process is what is known as “black mass”: a granular or powdered mixture of graphite and metals such as lithium, cobalt, copper, nickel, and manganese, which is produced during the processing of used batteries. Precise analysis of its composition is crucial—both for assessing the quality of the raw materials and for the performance of new batteries. The challenge lies not only in the complexity of the matrix but also in the efficiency of the analytical process: Different elements require different flame types and calibration strategies, and manual dilution steps slow down routine operations. This application note demonstrates how the analysis of major elements in black mass from lithium iron phosphate (LFP) batteries can be automated and reliably performed using High-Resolution Continuum-Source Flame AAS (HR-CS AAS).

By combining rapid sequential measurement with automatic sample dilution, aluminum, copper, and lithium can be determined in a fully automated analytical process—without element-specific lamp changes and without manual intervention when measurement ranges are exceeded. The system’s high spectral resolution also enables the identification and correction of potential spectral interferences directly at the analyte peak.

For four LFP black mass samples of varying particle sizes, recovery rates in the range of over 90% were determined following acid extraction—an indication of matrix-free analysis. The relative standard deviation of the triplicate measurements was consistently below 2%, underscoring the method’s reproducibility.

The complete application note details the method parameters, instrument configurations, and sample preparation steps used—as well as how the results for the individual samples differ in detail.