Chemical and Biomolecular Engineering
Faculty Advisor: Alexander Dowling
Revolutionizing Lithium-Ion Battery Recycling with Membrane Separations: Multiscale Modeling, Optimization, and Uncertainty Quantification
The importance of lithium-ion batteries (LIBs) is evident from their ubiquity in society and the 2019 Nobel Prize in Chemistry. Despite great advances since the 1970s, there remains a pressing need for sustainable LIB recycling technologies. Furthermore, worldwide production of lithium (Li), cobalt (Co), and other raw materials are insufficient to meet their projected demand over the next decade1 necessitating their secondary mining (recycling) from spent LIBs. Traditional processes that recycle LIBs are energy intensive and use large volumes of environmentally insulting solvents and high strength acids in leaching processes to extract metal rich solutions for further processing2. Relative to conventional technologies, membrane separations have demonstrated significant advantages in sustainability and energy efficiency3. Specifically, self-assembled copolymers, due to their nanoporous structure and pore wall functionalization enable the separation of similarly sized solutes via chemical affinity and can replace the solvent used in current LIB recycling technology. However, there is no clear understanding of the interfacial and thermodynamic phenomena underlying the chemically-selective transport mechanisms needed to separate molecules with comparable sizes such as Li and Co (atomic radii 1.8 Å and 2.0 Å respectively) which hinders the development of membrane materials for this task. Another challenge is the recovery of high purity products from a membrane separations unit. The formation of salt precipitate layers at the membrane interface when the feed side solution approaches the solubility limit prevents the extraction of high purity products, which also prevents the direct staging of these units.
References: 1. Bloomberg NEF Electric Vehicle Outlook, 2019; 2. X. Zeng et. al., Crit. Rev. Environ. Sci. Technol., 2014, 44, 1129; 3. W. A. Phillip, et al. Science, 2011, 333, 712;