Classification of spent Li-ion batteries based on ICP-OES/X-ray characterization of the cathode materials

Development of lithium-ion batteries (LIBs) during the latest decades resulted in improved performances of the new integrated cathode materials and in their wide applications. This rapid expansion of new materials led to the intensive replacement of the old-fashioned, traditional materials and increased a simultaneous accumulation of both kinds of materials at extremely hazardous electronic waste sites, which additionally increased an urgent need for their recycling. Most importantly, in this way, spent LIBs may further serve as a significant source of valuable metals such as Li and cobalt. However, one of the key problems in LIBs recycling is the absence of a precise battery classification/sorting based on the chemical composition of the used cathode material. In this paper, characterization of the cathode material was performed regarding chemical composition of 40 samples of spent LIBs using inductively coupled plasma - optical emission spectrometry and X-ray diffraction. Preparation of the samples, (pretreatment) included: discharging, dismantling, separation of the main components (cathode, anode and the separator), and detachment of the cathode material from the aluminium foil. The obtained results showed that, in the investigated commercially available LIBs, lithium cobalt oxide was the most frequently used (cathode) material.