The transition to a circular economy vision must handle the increasing request of metals required to satisfy the battery industry; this can be obtained by recycling and feeding back secondary raw materials recovered through proper waste management. Here, a novel and green proof‐of‐concept was developed, based on deep eutectic solvents (DESs) to fully and easily recover valuable metals from various cathode active materials, including LiMn2O4, LiNi0.5Mn1.5O4, and LiNi0.8Co0.2O2. DES composed of choline chloride and lactic acid could leach Li, Mn, Co, and Ni, achieving efficiency of 100 % under much milder conditions with respect to the previous literature. For the first time, to our best knowledge, a two‐step approach was reported in the case of LiNi0.8Co0.2O2 for selective recovery of Li, Co, and Ni with high yield and purity. Furthermore, other cathode components, namely aluminum current collector and binder, were found to be not dissolved by the proposed DES, thus making a simple separation from the active material possible. Finally, this strategy was designed to easily regenerate and reuse the leaching solvents for more than one extraction, thus further boosting process sustainability.

No abstract

Sustainable management of spent lithium-ion batteries, LIBs, is an urgent and critical challenge due to the number of such devices reaching the end-of-life. Recycling can offer a path for the recovery of valuable raw materials such as lithium and cobalt, whose supply is critical. Thus, it is mandatory to develop efficient ways for the selective recovery of Li and Co from the cathode degradation processes. In this study the most updated organic acids-based processes for the degradation of LiCoO 2 , the most common LIBs cathode, is explored to obtain a leached solution containing Li and Co. The possibility to exploit the 3-methyl-1-octylimidazolium thenoyltrifluoroacetone, Omim-TTA, ionic liquid was demonstrated to efficiently separate Li and Co. In particular it was possible to recover > 70 % of Li and separate it from Co using this ionic liquid, independently from the organic acid used for the leaching procedure and adding EDTA to the aqueous phase. The quantification was carried out through ICP analysis; the recovering of the unaltered ionic liquid was also demonstrated, to further increase the global sustainability of the process.

Lithium metal batteries (LMBs) are a key product for sustainable and efficient electric transport. Long-life and safe LMBs require the development of solid or semisolid (e.g., gel polymer) electrolytes capable of blocking lithium dendrites. In this context, Janus double-faced membranes (JMs) offer interesting perspectives, as they allow for modulating the properties of each side according to specific requests. In this paper, we report on facile fabrication via the solvent casting of JMs based on poly(vinylidene fluoride hexafluoropropylene) (PVDF-HFP). Here, an electronically insulating layer containing Al2O3 is in contact with the anode, whereas a mixed ionically–electronically conducting layer containing Al2O3, carbon nanotubes, and Super P carbon black is in contact with the cathode. We also investigate the role of the JM thickness and show that a 40 μm membrane allows for ~45% of the specific nominal capacity at 2C with Coulombic efficiency of ~100%. The proposed JMs are very promising for LMBs.