Use of Microwave-Assisted Deep Eutectic Solvents to Recycle Lithium Manganese Oxide from Li-Ion Batteries

Abstract

To realize efficient recycling of lithium manganese oxide (LMO) from spent Liion batteries, microwave-assisted deep-eutectic solvent (DES) treatment is proposed. The effects of the DES, temperature, time, and liquid/solid (L/S) ratio on the leaching efficiency were studied by orthogonal and single-factor experiments. The results of the orthogonal experiments indicated that the effects of each factor on the leaching of Li and Mn ions lay in the following order: DES > L/S ratio > temperature > time. The results of the single-factor experiments indicated that the leaching efficiencies of both Li and Mn ions reached 96% under the condition of choline chloride-oxalic acid (ChCl-OA), 15 min, 75°C, and L/S ratio of 6 g/0.1 g. Microwave-assisted DES treatment is highly efficient for recycling LMO from Li-ion batteries, greatly decreasing the leaching time from several days to less than 1 h even at 75°C in comparison with the traditional heating method.

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

“…[18] Additionally, an extraction yield for any target metal (Co, Ni, Mn) higher than 90 % was attained after only 4 h, and a maximum extraction yield close to 100, 93, and 94 % for Co, Ni, and Mn, respectively, was reached after 6 h. To date the highest extraction yield was reported for Co (100 � 3 %) using ethylene glycol:choline chloride (EG:CC) DES, [5,7,8,10,12] almost equal to that obtained using DES formulated using organic acid as hydrogen bond donor. [10,26] To evaluate whether the dissolution of metals was influenced by unknown species contained in the real waste LIBs black mass, a leaching test with duration of 24 h was performed with DESTT by employing commercial NMC111 (LiNi 1/3 Mn 1/3 Co 1/ 3 O 2 ) and NiO. Extraction yields close to those attained with the black mass were found (Figure 1d), excluding that unknown species from the black mass could have influenced metals dissolution.…”

Deep Eutectic Solvents: Green Approach for Cathode Recycling of Li‐Ion Batteries

“…Very recently, microwave-assisted treatment was employed to enhance the leaching efficiency using choline chloride-oxalic acid (ChCl-OA). [79] The report showed that the leaching efficiencies of both Li and Mn ions reached 99% and 96%, respectively, with only 15 min of microwave heating at 75 C. Although the result , with concentrations of 9.9 Â 10 3 ppm (red line), 7.9 Â 10 3 ppm (dark blue line), 6.6 Â 10 3 ppm (orange line), 4.9 Â 10 3 ppm (yellow line), 3.9 Â 10 3 ppm (light blue line), 3.0 Â 10 3 ppm (dark green line), 2.0 Â 10 3 ppm (gray line), 1.0 Â 103 ppm (light green line), and 0.5 Â 10 3 ppm (purple line). Adapted with permission.…”

Status and advances of deep eutectic solvents for metal separation and recovery

“…In addition, with the assistance of microwave, the oxaline could efficiently recycle both Li and Mn ions from spent LIBs with a high extraction efficiency of 96% at only 75 °C with a leaching time of 15 min. 212 Additionally, Schiavi et al (2021) 213 focused on improving the selectivity of the DESs-based solvent extraction process towards the target metals (Co, Mn) over the impurities (Fe, Al and Cu). They developed a novel solvometallurgical process containing two successive DES leaching stages conducted at different temperatures (as shown in the flow diagram in Fig.…”

“…35,36 In addition, with the assistance of microwave, the oxaline could efficiently recycle both Li and Mn ions from spent LIBs with a high extraction efficiency of 96% at only 75 °C with a leaching time of 15 min. 212 Furthermore, green leaching processes using DESs were approached to selective extraction of various metal ions from other e-waste, including end-of-life permanent magnets, 130,214 lamp phosphor waste, 215 and printed circuit boards (PCB). 96,118 Specifically, the guanidine hydrochloride-lactic acid (GUC-LAC) combined DES was screened from nine kinds of guanidine-based DESs as the best leachant to selectively extract the rare earth elements, neodymium (Nd), from the end-of-life permanent magnets with a high separation factor (>1300) between Nd and Fe through a simple selective dissolution step followed by precipitation process with oxalic acid.…”