AbstractElectrodeposition of Cobalt and Nickel for Hydrometallurgical Lithium Ion Battery Recycling by Anthony Castillo Reyes Master of Science in Engineering University of California, Irvine, 2023 Associate Professor Iryna Zenyuk, Chair Battery recycling is the solution for creating a closed loop system between manufacturing and production of batteries to the end-of-life batteries from cars to energy storage. With growing interest in electric vehicles creating inevitable battery waste, a scalable and efficient recycling process is needed for this increasing demand. The goal of this study is to electrochemically deposit cathode material from a leached solution to incorporate into existing hydrometallurgical battery recycling processes. Cobalt and nickel were galvanostatically deposited from a simulated leached cathode solution of NMC, producing 0.46 g of deposit material with a held current of -0.25 A for 4900 s. This material resulted in both cobalt and nickel depositing in a 1:1 ratio and is suitable for the construction of new cathode material recycling from end-of-life batteries. Moreover, poly[diallyldimethylammonium chloride] was incorporated as an electrode coating for the separation of cobalt and nickel. This addition resulted in a lighter deposit material of 0.39 g and was found unsuccessful in separation. The inability to separate the metals was attributed to the separation occurring only at the surface of the electrode.