A Simple Process to Recover High-Purity Electrode Blackmass Provided for Regeneration from Spent LiFePO4 Batteries

Abstract

Pulverizing and sieving are commonly used techniques in the recycling of waste batteries to separate valuable components (electrode blackmass). However, this method results in the separated blackmass with high levels of Al and Cu impurities, making it unsuitable for direct regeneration (a promising post-treatment technique for electrode blackmass). Here, a process optimization scheme with multiple pulverizing and sieving was proposed to reduce the Al and Cu contents in the separated cathode and anode blackmass to 0.046% and 0.359%, respectively, well below the threshold for direct regeneration. Additionally, the recovery rate of cathode and anode blackmass was also achieved, reaching 95.392% and 98.674%, respectively. Specifically, the mechanisms affecting the separation efficiency and the synergistic effects of various factors (including mesh size, pulverizer load, pulverizing time, and process steps) in electrode blackmass separation during pulverizing and screening processes are deeply explored. The optimal process parameters and process steps were determined. Material characterization showed that the separated cathode and anode black powder can be directly used for regeneration. The process proposed in this study can realize large-scale production and provide a reference for the practical application of regeneration technology.