Characteristics of crushed battery waste and mechanical pre-treatment at laboratory scale

The study aimed at investigating the characteristics and mechanical processability of primary crushed E-bike and power tool batteries. Both samples, the e-bike and power tool, were sieved into 12 fractions (Sieve sizes of 0.5 – 63 mm) with rather similar size distribution. Gas emissions from all the fractions were also monitored with FTIR, and HF detector was used to identify HF. No HF was detected, but carbon emissions (e.g. CO2) were detected from the sample fractions. After emission tests, the power tool sample was discarded, and the study was refocused on the E-bike sample which was divided into two parts (composed of individual size fraction) and were further inspected. The < 4 mm fractions were analysed separately with XRF, and the results treated in aggregate indicated the presence of NMC-111 type cathode materials. The size fractions > 4 mm were visually inspected for classification as well as liberation purposes. Significantly, undamaged cells were detected due to the primary crushing. In particular, poor liberation was identified upon Al cathode foils, which is expected due to the polymeric binders. The mechanical treatment experiments showed that significant share of damaged battery cells was removed with magnetic separation whereas cathode and anode as well as plastics continued to eddy current separation. Eddy current enriched anode and cathode particles to splitter fraction, the recoveries were 32 and 28 wt% respectively. This study concentrated on preliminary suitability of the eddy current separation on crushed battery wastes. Despite the rather low recoveries, a separation property of anode and cathode particles was observed with eddy current. In this task, the raw material was only primary crushed, the foils were not fully liberated, which decreases the recoveries.