2025 AIChE Annual Meeting

Optimizing the Recovery of Precious Metals during Lithium-Ion Battery Recycling

Lithium-ion batteries (LIBs) have become integral to modern technology due to their broad range of applications. However, the growing demand for LIBs raises geopolitical challenges in sourcing critical metals and poses significant environmental risks when spent batteries are improperly disposed of. In a strive towards sustainability, recycling introduces greener pathways towards recovering precious metals from spent LIBs, reducing resource wastage, and promoting the circular economy. In heat-based recycling, LIBs are typically subjected to incineration, roasting, and smelting. Although effective, these thermal treatments can be highly energy-intensive and emit air pollution. Alternatively, liquid-based pathways, such as leaching, utilize a solvent to extract metal particles into an aqueous solution for collection. With low energy consumption and low waste gas emission, leaching can be considered the environmentally friendlier recycling option. Organic acids and deep eutectic solvents are promising leaching agents because of their high metal-dissolution efficiency, low toxicity, biodegradability, and tunable chemical properties, making them attractive for environmentally sustainable recovery of valuable metals. Although several studies have explored the effectiveness of both solvents, a comprehensive comparison of the aforementioned leaching solvents and microwave-assisted leaching to recover precious metals from spent LIBs is scarcely reported, especially under the same testing conditions. Therein lies the motivation of this study.
The study aims to understand the performance of each solvent under leaching conditions for different metals. In this research, inductively coupled plasma mass spectrometry (ICP-MS) was used to quantify the concentration of precious metals such as Lithium (Li), Manganese (Mn), and Cobalt (Co) in each sample post-leaching. Preliminary results show that across all metals, AA has extracted more metals from LIB powder compared to DES. Moreover, the introduction of a common reductant such as glucose (G) has shown synergistic effects with DES at certain temperatures, and inverse effects with AA overall. As of current, the chemical structure and composition of pre- and post-leaching samples are under further assessment using Scanning Electron Microscopy, Energy Dispersive X-ray spectroscopy, and X-Ray Diffraction. Additionally, kinetic studies will be conducted on the best leaching pathways to observe how metals are extracted at each time interval.