Direct Recycling of Spent LiNi_0.5Co_0.2Mn_0.3O₂ Cathodes Based on Single Oxalic Acid Leaching and Regeneration under Mild Conditions Assisted by Lithium Acetate

Abstract

The tremendous consumption of lithium-ion batteries (LIBs) raises concern about sustainable resources especially for the valuable metals. Recycling valuable metals from spent LIBs is expected to meet the demand growth of LIBs. Herein, a novel approach combined with oxalic acid leaching, calcination relithiation, and annealing is proposed to regenerate spent LiNi0.5Co0.2Mn0.3O2 (NCM523) cathodes. This approach can reduce the recycling cost, accompanied with small energy consumption. Moreover, almost 98% of the valuable metals (Ni, Co, Mn) can be directly regenerated. The regenerated NCM523 cathode exhibits an initial capacity of 146.1 mAh g–1, with ∼85% capacity retention after 100 cycles. This work not only provides an efficient and simple method for recycling spent cathodes but also gives a new perspective of sustainable manufacturing of energy materials.

Review of Ultrasound-Assisted Recycling and Utilization of Cathode Materials from Spent Lithium-Ion Batteries: State-of-the-Art and Outlook

“…Acid leaching is the most utilized method for recovering metals from the cathode materials of SLIBs. Inorganic acids, organic acids, ionic liquids, and deep eutectic solvents are mainly utilized as leaching agents to develop an environmentally friendly recycling process. , The mechanical, thermal, and chemical effects induced by the cavitation improve the mass transfer efficiency, provide additional redox agents, and remove the passivation layer on the particle surface …”

Stacking Fault Formation in LiNi0.6Co0.2Mn0.2O2 during Cycling: Fundamental Insights into the Direct Recycling of Spent Lithium-Ion Batteries

“…The valuable metals in freshly fabricated LIBs were originally produced from various mined ores through pyrometallurgy, hydrometallurgy, or both. Pyrometallurgy includes a high-temperature heating process (>∼ 800 °C) for reducing metal oxides to form alloys, , whereas hydrometallurgy consists of acid leaching and solvent extraction processes. , In principle, the valuable metals in spent LIBs can be recovered by these methods, which have advantages for mass production and the purity of the metals. − However, destruction-and-regeneration-type recycling consumes more total energy than that for producing these metals from ores and increases the risk of secondary environmental pollution; thus, many researchers have attempted to directly recycle these (positive) electrode materials by simply reactivating them as a more efficient strategy for producing these materials. − …”

Retrieving Spent Cathodes from Lithium‐Ion Batteries through Flourishing Technologies

“…without using high pressure. [35][36][37] However, the directrelithiation can restore their original electrochemical properties only if lithium-ion loss is the primary aging mechanism. Again, it is a big challenge to sort spent cathode materials which are suitable for direct relithiation.…”

“…The hydrothermal process has been directly employed for the regeneration of suitable cathode material like LiCoO 2 , LiNi 1/3 Co 1/3 Mn 1/3 O 2 , LiNi 0.5 Co 0.2 Mn 0.3 O 2 , and LiNi 0.6 Co 0.2 Mn 0.2 O 2 etc. without using high pressure [35–37] . However, the direct‐relithiation can restore their original electrochemical properties only if lithium‐ion loss is the primary aging mechanism.…”