Efficient Recovery of Value Metals from Spent Lithium-Ion Batteries by Combining Deep Eutectic Solvents and Coextraction

Abstract

The advancement of the electric vehicle industry has inevitably resulted in the increased production and numerous scraps of lithium-ion batteries (LIBs), among which the nickel cobalt manganese ternary material has become the fastest growing and largest proportion material in the lithium battery cathode material market. Therefore, a practical and effective method to recycle spent LIBs must be established. In this study, an efficient recycling method was proposed to leach value metals from cathode materials via the excellent solubility of deep eutectic solvents to metals, and regenerated LiNi1/3Co1/3Mn1/3O2 was prepared via coextraction and coprecipitation. 91.63% of Li, 92.52% of Co, 94.92% of Ni, and 95.47% of Mn are leached from the recycled cathode electrode. The kinetic experiments indicated that the leaching process fitted well to the shrinking core model controlled by chemical reactions. The value metals could be extracted with high efficiencies by adjusting the operating parameters in the step of coextraction. Moreover, the electrochemical tests of the regenerated ternary material revealed that the material had an excellent electrochemical performance. The proposed method, which can realize the sustainable development of spent LIBs, has great potential in the deep recycling of spent LIBs.

Decomposition of Deep Eutectic Solvent Aids Metals Extraction in Lithium‐Ion Batteries Recycling

“…More recently, using the same DES composition, Wang et al. obtained, already with pristine DES, an extraction yield higher than 90 % both for Ni and Co by leaching the cathode material in a hydrothermal reactor at 190 °C for 24 h [21] . This result seemingly contradicts the selective extraction of Co attained through our leaching test with pristine DES at 180 °C.…”

“…However, in view of our results of leaching with the reused DES, the faster thermal decomposition of DES induced according to Wang et al. by the larger leaching temperature could explain the apparent contradiction [21] …”

“…The increased selectivity of Co extraction as compared to that of Ni excludes the complex separation of Ni and Co, considerably simplifying the downstream recovery of Co. [20] However, replicating the leaching with the residual DES left after the recovery of metals, we found an increase in the Ni extraction yield from about 10 to 40 % without any significant change in the extraction of Co, corresponding to the loss of original DES extraction selectivity. [18] Above 90 °C, DES is not stable, and we already reported several decomposition products after leaching the LIBs black mass at 180 °C for 24 h. [18] More recently, using the same DES composition, Wang et al obtained, already with pristine DES, an extraction yield higher than 90 % both for Ni and Co by leaching the cathode material in a hydrothermal reactor at 190 °C for 24 h. [21] This result seemingly contradicts the selective extraction of Co attained through our leaching test with pristine DES at 180 °C. However, in view of our results of leaching with the reused DES, the faster thermal decomposition of DES induced according to Wang et al by the larger leaching temperature could explain the apparent contradiction.…”

“…However, in view of our results of leaching with the reused DES, the faster thermal decomposition of DES induced according to Wang et al by the larger leaching temperature could explain the apparent contradiction. [21] Some results about the decomposition of DES based on choline chloride and ethylene glycol in applications not related to metal extraction were reported, but no previous work systematically investigated whether and how decomposition products can influence the ability of DES to dissolve metal oxides. [22][23][24][25] We found only few recent articles where the reuse of DES is analyzed.…”

Deep eutectic solvent for spent lithium-ion battery recycling: comparison with inorganic acid leaching

“…For instance, leaching efficiencies of 91.63%, 92.52%, 94.92%, and 95.47% for Li, Co, Ni, and Mn, respectively, were obtained in ChClethylene glycol DESs (molar ratio of 1 : 2) from an NCM battery. 120 For NCO batteries, almost 100% of Li, Co, and Ni were leached through ChCl-lactic acid DESs (molar ratio of 2 : 1). 121 Compared with DESs, inorganic acids, including H 2 SO 4 , HCl, HNO 3 and H 3 PO 4 , are superior in the leaching performance of Li and Co from spent LIBs.…”