Recycling of Cathode active materials from Spent Lithium-ion Batteries (LIBs): Effective Methodology for Environmental Remediation

Abstract

In this work, three different solvents such as N, N-Dimethylformamide (DMF), N-Methyl-2-pyrrolidone (NMP) and Dimethyl sulfoxide (DMSO) were used to recycle cathode active materials (CAM) from spent lithium ion batteries (LIBs). Both calcination and solvent dissolution processes were used. The cathode active materials recycled from DMF, NMP and DMSO solvent dissolution process were named as CAM 1, CAM 2 and CAM 3, respectively. Initially, cathode electrode cut into small pieces and then baked at 600 °C for 7 h in tube furnace under argon environment. In the send step baked electrode transferred to solvent and then continue reflux reaction 24 h. In the final step the Al foils were separated from the solution and the cathode active material were collected by vacuum filtration and heat treatment. The structure and morphology of the cathode active materials were characterized by using XRD, Raman, SEM and TEM instruments. The SEM morphology shows that PVDF polymer and acetylene black removed from the cathode active materials by calcination and solvent dissolution process. EDAX and mapping shows that CAM 3 is more pure and uniform morphology than CAM 1 and CAM 2 cathode active materials. The elemental analysis shows that CAM 1, CAM 2 and CAM 3 are NMC 532 cathode powder with a chemical formula Li (Ni5Mn3Co2) O2. XRD results show that R3m layered structure with strong crystalline peaks for all three recycled cathode active materials. Raman analysis confirms the presence of metal oxide.