Hydrochloric acid, nitric acid, sulfuric acid and several organic acids like lactic acid, citric acid, formic acid, and tartaric acid were tested in previous works 12,13 while many complete flowsheets implementing chemical operations such as leaching and solvent extraction were proposed. 11 This process usually involves acid leaching to dissolve the cathode material, followed by solvent extraction or precipitation to separate each metal. Hydrometallurgy appears as the good technology to extract valuable metals from spent LIBs because it can recover all metals contained in spent LIBs including lithium unlike pyrometallurgy. Nevertheless, only few studies are devoted to investigate NMC 811 recycling while more papers concerns the development of recycling processes for the recovery of metals from NMC 111. Furthermore, the use of NMC 811 instead of NMC 111 will undoubtedly reduce cobalt demand and supply risk for this element, which is a critical metal. 7 During the last years, more and more attention has been paid to LiNi 0.8Mn 0.1Co 0.1O 2 (NMC 811) since this material is considered a good alternative to LiNi 1/3Mn 1/3Co 1/3O 2 (NMC 111) for the next generations of LIBs because of the good compromise between its performance and its stability. Cobalt stabilizes layer structure of materials and also improves rate capability. Manganese dominates the safety and cycle life. High content of nickel results in high capacity and rate capability but also in poor safety. In these electrodes, nickel changes its oxidation states during charge–discharge cycling of the battery due to lithium insertion–deinsertion (Ni 2+ ↔ Ni 4+). Ternary composites Li(Ni 1− x− yMn xCo y)O 2 are widely used as cathode material in LIBs. 6Ĭommercial LIBs usually use various types of Li containing oxides and phosphate as cathode materials, such as LiCoO 2, LiMn 2O 4, LiFePO 4, LiNi 1− x− yMn xCo yO 2 (NMC, or sometimes also called NCM), etc. 5 However, in many places, the word “recycling” generally only refers to collection, sorting and dismantling of battery wastes, and does not include the further process of raw material recovery from these wastes. Therefore, recycling of spent LIBs presents significant environmental and economic importance. 3,4 In addition, lithium and cobalt recovery from primary and spent LIBs is an important topic as Co and Li are classified as critical energy materials by the US, EU and UN. On the other hand, inappropriate disposal of large amounts of spent LIBs can lead to serious environmental and safety issues.

1,2 Concerns have been raised as the increasing demand of raw materials may not be easily satisfied, especially for countries where resource availability is limited. 1 Introduction Since 1991, lithium-ion batteries (LIBs) have been widely used in electronic devices and electric vehicles, because it can provide high energy and power per unit of battery weight. Finally, the overall reaction of NMC 811 leaching by hydrochloric acid can be written as: 2LiMO 2,(s) + 8HCl (l) ⇌ 2LiCl (l) + 2MCl 2,(l) + 4H 2O (l) + Cl 2,(g). In the second step, the new phase is dissolved (limiting step): 2 nd step. In the first step, NMC is transformed into a new phase which contains less lithium (2.8 < n < 3.6): 1 st step: where M = Ni, Mn, Co. Analysis of leaching kinetic data evidenced that NMC 811 dissolution occurs in two steps. This study shows that the leaching behaviour of lithium is quite different than those observed for nickel, cobalt and manganese contained in NMC 811 since lithium dissolution is faster than those observed for nickel, cobalt and manganese. This paper investigates the reactions involved when LiNi 0.8Mn 0.1Co 0.1O 2 (NMC 811), which is one of the most promising positive electrodes for the next generation of lithium-ion batteries, is leached by hydrochloric acid.

Nmc cathode