Recycle of End-of-Life NMC 111 Cathodes By Electrochemical Relithiation

Abstract

Recycling end-of-life (EoL) lithium ion batteries (LIBs) is of great significance to provide additional transition metal resources and alleviate environmental pollution from batteries wastes, but lags far behind compared with that of lead-acid batteries in the recycling industry. Conventional LIBs recycling methods including pyrometallurgy and hydrometallurgy processes have limitations with regard to energy inefficiency, extensive gas treatment, as well as complex chemical reactions and purification steps for leaching and separating metals. This project is part of ReCell which is a collaborative effort to develop efficient and economical recycle and reuse methods for EoL battery cathodes. The objective of this work is to recover the EoL cathode performance and structure by electrochemical relithiation using a Li metal sacrificial anode since Li ion (Li+) inventory loss plays a significant role for the cathode degradation. The morphology, composition and structure of the initial NMC 111 pristine and chemically delithiated powders used for the ReCell project were characterized through Raman spectroscopy, FIB SEM and TGA. Chemically Delithiated NMC 111 anodes have been prepared and relithiated using a range of temperatures and currents in order to optimize the electrochemical relithiation for application in a roll to roll process. Initial results indicate that elevated temperatures will be necessary to facilitate fast relithiation of the NMC 111 cathodes with the addition of more thermally stable electrolytes. Analysis and characterization of aged NMC 111 anodes in pouch cells is applied to verify the effectiveness of electrochemically relithiated anodes and to compare to the chemically delithiated NMC 111 model material. This study provides more understanding towards developing a battery material recovery process that will potentially recover specialized material morphology and help to minimize energy use and emissions. Figure 1