Closed-loop recycling of spent lithium-ion batteries based on selective sulfidation: An unconventional approach

A facile and efficient recovery method of valuable metals from spent lithium-ion batteries via simultaneous leaching and separation strategy

Traditional hydrometallurgical recycling methods present challenges including complex processes, significant metal loss, and high costs. To address these issues, this work introduces a facile and efficient recycling method for spent ternary cathode materials, which combines acid leaching and oxidation as well as ammonia leaching. Firstly, careful control of the phosphoric acid concentration and sodium persulfate dosage allows for the selective leaching of Li and Ni in the process of acid leaching and oxidation, and thus their leaching efficiencies can reach as high as 99.3 % and 97.2 % respectively. Meanwhile, Co and Mn can be separated in the form of Co3O4 and MnO2 remaining in the waste residues. Secondly, based on the stability difference of complexes formed by cobalt and manganese with ammonia, Co can be selectively leached from waste residue through ammonia leaching, with the leaching efficiency reaching 93.2 %, while Mn is separated via reacting with CO32- in the solution to form MnCO3. Moreover, the mechanisms of selectively leaching Li and Ni during acid leaching and oxidation processes are revealed using characterization techniques such as XRD, ICP, SEM-EDS, and thermodynamic analysis. Finally, economic analysis shows that the benefits of this approach in terms of battery reuse are considerable, and there are clear advantages in terms of process simplification and operational safety. Compared to traditional hydrometallurgical recovery methods, which typically involve sequential separation after metal leaching, the proposed method achieves simultaneous leaching and separation of metals, thereby simplifying the recovery process and reducing metal losses.

A closer look at lithium-ion batteries in E-waste and the potential for a universal hydrometallurgical recycling process

The demand for lithium-ion batteries (LiBs) is rising, resulting in a growing need to recycle the critical raw materials (CRMs) which they contain. Typically, all spent LiBs from consumer electronics end up in a single waste stream that is processed to produce black mass (BM) for further recovery. It is desired to design a recycling process that can deal with a mixture of LiBs. Hence, this study investigates the structure and composition of battery modules in common appliances such as laptops, power banks, smart watches, wireless earphones and mobile phones. The battery cells in the module were disassembled into cell casing, cathode, anode and separator. Then, the cathode active materials (CAMs) were characterized in detail with XRD-, SEM-, EDX- and ICP-OES-analysis. No direct link was found between the chemistry of the active materials (NMC, LCO, LMO, LFP etc.) and the application. Various BM samples were submitted to a leaching procedure (2 M H2SO4, 50 °C, 2 h, 60 g BM/L) with varying concentration (0-4 vol%) of H2O2 to study the influence of their chemical composition on the dissolution of Li, Ni, Mn and Co. Only a part of the BMs dissolved completely at 4 vol% H2O2, which was attributed to the oxidation state of the transition metals (TMs). Exact determination of H2O2 consumption by redox titration confirmed this hypothesis.

Research on the facile regeneration of degraded cathode materials from spent LiNi0.5Co0.2Mn0.3O2 lithium-ion batteries

Rational reusing the waste materials in spent batteries play a key role in the sustainable development for the future lithium-ion batteries. In this work, we propose an effective and facile solid-state-calcination strategy for the recycling and regeneration of the cathode materials in spent LiNi0.5Co0.2Mn0.3O2 (NCM523) ternary lithium-ion batteries. By systemic physicochemical characterizations, the stoichiometry, phase purity and elemental composition of the regenerated material were deeply investigated. The electrochemical tests confirm that the material characteristics and performances got recovered after the regeneration process. The optimal material was proved to exhibit the excellent capacity with a discharge capacity of 147.9 mAh g-1 at 1 C and an outstanding capacity retention of 86% after 500 cycles at 1 C, which were comparable to those of commercial NCM materials.

Resource recovery and regeneration strategies for spent lithium-ion batteries: Toward sustainable high-value cathode materials

Traditional cathode recycling methods have become outdated amid growing concerns for high-value output and environmental friendliness in spent Li-ion battery (LIB) recycling. Our study presents a closed-loop approach that involves selective sulfurization roasting, water leaching, and regeneration, efficiently transforming spent ternary Li batteries (i.e., NCM) into high-performance cathode materials. By combining experimental investigations with density functional theory (DFT) calculations, we elucidate the mechanisms within the NCM-C-S roasting system, providing a theoretical foundation for selective sulfidation. Utilizing in situ X-ray diffraction techniques and a series of consecutive experiments, the study meticulously tracks the evolution of regenerating cathode materials that use transition metal sulfides as their primary raw materials. The Li-rich regenerated NCM exhibits exceptional electrochemical performance, including long-term cycling, high-rate capabilities, reversibility, and stability. The closed-loop approach highlights the sustainability and environmental friendliness of this recycling process, with potential applications in other cathode materials, such as LiCoO2 and LiMn2O4. Compared with traditional methods, this short process approach avoids the complexity of leaching, solvent extraction, and reverse extraction, significantly increasing metal utilization and Li recovery rates while reducing pollution and resource waste.