Cumulative leaching of lithium-ion battery (LIB) cathode andanode in two-component deep eutectic solvent

In this research, the leaching of the mixture of cathode and anode materials of lithium-ionbatteries (LIBs) in a two-component deep eutectic solvent (DES) of choline chloride (ChCl)and p-toluenesulfonic acid (PTSA) has been investigated. A 1:1 molar ratio of ChCl:PTSA wasused to prepare DES. Leaching of mixed LIBs was investigated in the temperature range of 40-100 °C and the time range of 30-1440 min in DES. The results of the temperature investigationshow that the leaching efficiencies of iron, nickel, cobalt, copper, and manganese increase withincreasing temperature at a fixed time. For example, at 40 °C, the leaching efficiencies of iron,nickel, cobalt, copper, and manganese are 16.5, 46.5, 69.0, 48.4, and 64.3%, respectively. But,at 100 °C and a fixed leaching time of 1440 min, the efficiencies increase to 30.6, 97.8, 98.4,89.7, and 94.4%, respectively. Time, as another influential parameter in the LIBs leachingprocess, has a positive effect on leaching efficiency. As time increased, the leaching efficienciesof iron, nickel, cobalt, copper, and manganese increased. By enhancing time from 30 to 1440min, leaching efficiencies increased from 17.4% to 30.6% for iron, 53.2% to 98.4% for nickel,84.5% to 98.4% for cobalt, 51.3% to 89.7% for copper, and 80.3% to 93.5% for manganese.An important point to note is the ability of the two-component DES to dissolve highconcentrations of elements. Under the optimum conditions obtained from the experiments inthis research (temperature of 100 °C and time of 300 min), the concentration of iron, nickel,cobalt, copper, and manganese was found to be 108, 272, 1489, 920, and 503 mg.L-1,respectively. Considering the cumulative concentration of these elements, approximately 3295mg.L-1 has been dissolved in the deep eutectic solvent. Therefore, the results demonstrate thatthe two-component solvent of choline chloride and p-toluenesulfonic acid has a good ability todissolve the mixture of LIBs.

Cumulative leaching of lithium-ion battery (LIB) cathode andanode in two-component deep eutectic solvent Keywords:

Leaching , lithium-ion battery (LIB) , Deep eutectic solvent (DES) , Temperature effect , Time effect , choline chloride , p-toluenesulfonic acid.