Environment-friendly acids for leaching transition metals from spent-NMC532 cathode and sustainable conversion to potential anodes

Abstract

For a clean and sustainable world, energy storage systems like Li-ion batteries (LIBs) will play a vital role due to their wide range of applications. The exponential growth of batteries will lead to the generation of a substantial number of failed batteries in the near future. As a consequence, recycling will play a crucial role to reduce e-waste and to scale down the mining of virgin materials. Herein, we demonstrate a strategic approach to reduce e-waste and effectively reuse the same materials by regenerating batteries, enabling a circular economy. The study focuses on the recycling and regeneration of LiNi_0.5Mn_0.3Co_0.2O₂ (NMC532) cathode material via a hydrometallurgical process with two different environmentally friendly acids. The regenerated materials were characterized by X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. Regenerated mixed metal phosphide and oxide anodes exhibited excellent electrochemical performance in an LIB system. This work opens up the scope for a simple and scalable approach to develop the recycling and regeneration of NMC batteries, which will facilitate a circular economy, thereby leading the way for more developments in this field.