005

Title:

Leaching of valuable metals from spent-lithium-ion batteries (LIBs) using Organic Aqua Regia

Discipline: Environmental Engineering

Presenter:

Leqi Lin

Abstract:

Lithium-ion batteries (LIBs) have increasingly been used since 1991 in diverse electronic products such as camera, cellphone, laptop, and further for electrical vehicle. The market of cathode of LIBs is growing from $7 billion in 2018 to $58.8 billion by 2024. LIBs usually run 500-2000 cycles depending on the type of cathode and have 2-3 years of life span. These electronic waste (e-waste) with high concentrations of metals and toxic organic solvents may negatively affect our environment and human health. Material recovery from spent-LIBs system is not only necessary for the environmental protection, but also important for resource conservation. Hydrometallurgy has been considered as the most efficient way to recover Li and Co from LIBs by using inorganic acids. In this work, we investigated the recovery of Co and Li using ten dilution times Organic Aqua Regia (OAR) without the separation of cathode from Al foil which can reduce the complexity of pretreatment process. The metal leaching rate reached up to 0.035 mg-Li·ml-1·min-1 and 0.29 mg-Co·ml-1·min-1 depending on the metal species and other leaching conditions, which are comparable to the reported rates using other acids (i.e.,nitric acid, citric acid and succinct acid). The result shows the leaching efficiency for Co and Li are over 80%, 2 wt.% H2O2 under the temperature of 85oC for 60 minutes with ultrasonication (120W). Moreover, we characterized the changes of morphology and crystallinity of cathode materials before/after leaching by X-ray Diffraction, Raman spectrometer, SEM-EDS and Ultraviolet-visible spectroscopy to further understand the leaching mechanisms. This green chemical extraction or leaching method is aimed at improving the industrial metal recovery processes for LIBs.

Author(s):

Leqi Lin, Wen Zhang

Funding Acknowledgements:

US Environmental Protection Agency Pollution Prevention (P2) program (No: NP96259118-0)