Tribocatalytic recycling of lithium-ion batteries

In order to explore recycling solutions for used lithium-ion batteries (LIBs), a tribocatalytic method is proposed in this paper. Using ZnO nanoparticles as catalysts, the leaching rates of lithium and cobalt in lithium cobaltate batteries reached 95% and 84%, respectively. In Li-Co-Mn-Ni batteries, the leaching rates of lithium, cobalt, manganese and nickel were 96.61%, 90.00%, 76.06% and 61.78%, respectively. In the acid leaching system, the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO) of citric acid (CA) were in more appropriate positions, indicating that CA is more prone to redox reactions when rubbed on the surface of zinc oxide. Compared to H₂O, CA is more electrostatically polarized and can participate in more reactions through electron transfer on the ZnO surface. First-principle calculations of adsorption energies show that the interactions are stronger when CA molecules are located on the LCO (110) surface. The combination of theoretical calculations and experiments verified that the tribocatalytic weak acid leaching process is an effective ion leaching scheme. The free radicals generated during the catalytic process promoted the leaching of metal ions, thus enabling the recycling of cathode materials for lithium-ion batteries. In addition, this method has great potential for the reduction and leaching of ions.