Thus, the same acids were used for separation of foil coatings of varying chemistries which depended on the supplier.
Experiments were designed and conducted to find the lowest acid concentration, the lowest temperature, and the shortest time required for full separation of the coatings from the foils for each of the battery chemistries (manufacturers).
The optimum recycling condition was identified as the lowest acid concentration, the lowest temperature, and the shortest time required for full separation of the coatings from the foils for all cell chemistries (manufacturers).
The results of testing various HNO3 concentrations and temperatures identified that full separation of the coatings from the aluminum foils was possible within 83 s for samples from all manufacturers by using an HNO3 concentration of 2 mol/L at 70 °C.
The separation of the carbon coatings from the copper foils occurred within 65 s for all concentration and temperature conditions tested.
Therefore, for separation of the carbon coatings from the copper foils, 50 mL of 2.0, 1.0, and 0.5 mol/L solutions of sulfuric acid (95.0 98.0 %, Sigma-Aldrich Co, St . Louis MO) were prepared.
For separation of the cathode active coatings from the aluminum foils, 50 mL of 2.0, 1.0, and 0.5 mol/L solutions of nitric acid (70%%, Sigma-Aldrich Co, St . Louis MO) were prepared.
The differences between the LIB chemistries from the three manufacturers resulted in greater variations in the conditions required for full separation of the cathode active material coatings than of the anode coatings.
For the conditions tested, the separation of the cathode active material coatings from the aluminum foils tended to take longer time than the time required for the separation of the carbon coatings from the copper foils for each manufacturer.
In recent decades, hydrophobic hybrid metal or metalloid oxide (MO polymer composites are widely used in a variety of applications such as self-cleaning hydrophobic coatings [1 3], chemical separation of polar and nonpolar substances [4, 5], adsorption of organic contaminants, and removal of oil from the water surface [6, 7].
