New Bifunctional Deep-Eutectic Solvent for In Situ Selective Extraction of Valuable Metals from Spent Lithium Batteries

Abstract

A novel bifunctional deep-eutectic solvent (DES) based on glycol (EG) and oxalic acid dihydrate (OAD) was designed for efficient and selective extraction of valuable metals from spent lithium ion batteries (LIBs) cathode active materials (LiCoO 2 or Li 14.8 Ni 1.7 Co 8.5 MnO 30.5 ) under mild conditions, realizing complete in situ separation of Li and Co/Ni/Mn. The effects of different experimental parameters on Li and Co extraction efficiencies (η Li , η Co ) were explored by orthogonal and single-factor experiments in detail. Under the optimal conditions (90 °C, 5EG:1OAD, 12 h, 16 g/L), nearly 94.4 and 94.1% of Li, as well as trace amounts of Co/Ni/Mn (<1.2%), were separately leached from LiCoO 2 and Li 14.8 Ni 1.7 Co 8.5 MnO 30.5 into the filtrate, while the oxalate dihydrates (CoC 2 O 4 •2H 2 O or (Ni, Co, Mn)C 2 O 4 •2H 2 O) with nanorod structures were achieved. The specific leaching mechanism was elucidated. Moreover, the lithium oxalate (Li 2 C 2 O 4 ) with irregular particle morphology was also obtained by evaporating the filtrate at 200 °C. The reusability of the as-prepared DES (5EG:1OAD) for the LIBs was also studied. After three cycles of DES leaching, the η Li could still reach more than 93%, while almost all Co was remained in the solid phase. This study may shed light on developing bifunctional or even multifunctional DESs to achieve highly selective extraction of metals from LIBs.

Highly efficient lithium-ion battery cathode material recycling using deep eutectic solvent based nanofluids

“…Meanwhile, pseudo boric acid could have a positive effect on the leaching of LiMO 2 (2LiMO 2 + HO–(CH 2 ) 2 –OH + 2H + = 2M 2+ + O(CH 2 ) 2 O + H 2 O (ref. 38 and 63)). Therefore, besides the positive effect in terms of heat and mass transfer which has been proved by means of studying thermophysical properties and CFD simulation, BN, a nanoparticle featuring both acid and base sites, could be used as a base to inactivate PVDF and an acid to accelerate the leaching efficiency of metal species in spent LIBs.…”

“…The XRD spectra clearly show a typical response of Li(NiCoMn) 1/3 O 2 before and after DES nanofluid treatment indicating that the chemical composition did not considerably change during the liberation process. 39 A similar phenomenon was observed in the FTIR spectra; however, some minor peaks, such as 1117 cm −1 , 1500 cm −1 , and 1618 cm −1 which correspond to the C–F vibration, CH 2 scissoring and CC vibration of PVDF respectively, 59 weakened or disappeared to some degree presumably because of the removal of the organic binder during the liberation process with peaks representing Ni–O, Mn–O and Co–O remaining 60 (Fig. 6d).…”

“…Kinetics of the metal leaching process was also discussed. In the meantime, Guo et al 39 developed a bifunctional DES based on EG and oxalic acid dihydrate (OAD) for selective extraction of valuable metals from spent LIBs. They also demonstrated a novel strategy for selective extraction of Ni, Co, and Mn respectively from the spent LiNi x Co y Mn 1− x − y O 2 cathode through the regulation of the coordination environment of DESs.…”

Hydrogen Bond Network for Efficient and Stable Fully Ambient Air-Processed Perovskite Solar Cells with Over 21% Efficiency

“…It was found that ImA-SA-IPA was formed as a low melting point mixture, which may indirectly support the hydrogen bond interaction between ImA and SA (Figure S1). , Reported research on defect passivation showed that the introduction of organic molecules or low-dimension semiconductor material (wide bandgap) would inevitably hinder the transport of carriers between perovskite grains. On the contrary, while passivating the perovskite GB, bridging the independent perovskite grains might accelerate the carrier transport between perovskite grains.…”

Green recycling of spent Li-ion battery cathodes via deep-eutectic solvents

“…146 Despite reported attempts to reuse recovered DESs (often multiple times), there are limitations on leaching efficiency. 107,147 The…”