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

Abstract

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 (Ni 5 Mn 3 Co 2 ) O 2 . 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.

Boosting Osmotic Energy Harvesting from Organic Solutions by Ultrathin Covalent Organic Framework Membranes

“…Therefore, scientists have made tremendous efforts to explore and utilize renewable energy sources, especially focusing on nanofluid-based energy harvesting technologies, such as osmotic power generation. − Osmotic energy generated at the junction of sea and river has drawn tremendous attention due to its sustainability, widespread presence, and minimal variability in power output compared to intermittent energy sources like solar and wind power. − In addition to such natural salinity gradient, industrial processes (e.g., dyeing, weaving, medicine synthesis, and paper production) also produce huge volumes of waste organic solvents containing various concentrations of inorganic salts . Besides, the recycling of electrode materials in power batteries also yield massive organic waste solution containing salts of lithium, cobalt, and manganese . Instead of sending to on-site incineration immediately, extracting osmotic energy from these waste organic solutions through reverse electrodialysis (RED) represents a promising approach to reuse such industrial wastes as valuable resources and mitigate the ever-growing energy needs. ,− In this context, numerous nanofluidic membranes have been constructed from polymers, nanofibers, nanosheets, metal–organic frameworks (MOFs), and their hybrids to enable the directed transport of counterions and harvesting osmotic energy from waste organic solutions. − However, compared to extracting osmotic energy from aqueous systems, − power harvesting from organic solutions can be much more complicated owing to the high viscosity of waste organic solutions and the diverse array of ion–solvent, ion–wall, and solvent–wall interactions within nanofluidic channels.…”