Recycling Spent Lithium Ion Batteries and Separation of Cathode Active Materials: Structural Stability, Morphology Regularity, and Waste Management

Recycling of cathode active materials from spent lithium ion batteries (LIBs) by using calcination and solvent dissolution methods is reported in this work. The recycled material purity and good morphology play major roles in enhancing the material efficiency. LIBs were recycled by an effective recycling process, and the morphology and structure of the cathode active materials were studied. Both calcination and solvent dissolution processes were used to obtain the purified cathode active materials. The pristine cathode active material (CAM) sample was peeled off of the aluminum surface after thermal treatment at 700 °C for 5 h, and this was compared with the cathode active material, which was recycled by calcination and solvent dissolution processes (CAM-CA-SD). The structure and morphology were analyzed by XRD, Raman, XPS, SEM, and TEM. The morphology shows that PVDF polymer and carbon black were completely removed from the cathode active materials which were recycled by both calcination and solvent dissolution methods. EDAX curves and mappings show the presence of Ni, Mn, Co, and O in the cathode active material. The elemental analysis from EDAX shows that the recycled cathode active material from spent LIBs is NMC 532 Li (Ni₅Mn₃Co₂) O₂. The EDAX curves show that the PVDF polymer completely disappeared in the CAM-CA-SD sample. The surfaces of CAM and CAM-CA-SD recycled materials contain multiple oxidation states such as +3 and +2 states of Mn, Co, and Ni metal ions. The calcination and solvent dissolution methods have a strong impact on the cathode active material purity.