Abstract: Lithium-ion batteries (LIBs) are an indispensable component of the green revolution, and the growing demand for LIBs reflects this trend. As reliance on LIBs increases, sustainable metal recovery strategies are crucial to mitigating raw material scarcity and environmental concerns. This study examines commonly used and emerging lixiviants for metals extraction, balancing operational efficiency with environmental sustainability. Established mineral acids such as hydrochloric, sulfuric, and nitric acids are effective but pose ecological risks. On the other hand, organic acids present a promising alternative by reducing environmental impact but often compromising process efficiency. In addition to extensively studied organic acids, this review explores the potential of lesser-explored organic acid variants such as propionic and gluconic acids. Biometallurgical recovery, a hybridized alternative methodology to conventional hydrometallurgy, and electrochemical leaching, an emerging metal recovery method, are also explored to enhance sustainability. Furthermore, the review highlights the critical role of policy and regulatory frameworks in aligning recycling practices with circular economy principles and examines spent LIB recycling in China, the USA, and the European Union in this context. By exploring past and future trends, this work underscores the need for innovative, cost-effective, and environmentally responsible solutions in metallurgical processing.

Key words: Lithium-ion batteries, Sustainable metal recovery, Acid leaching, Lixiviants, Circular economy