Evolution of lithium-ion battery recycling: state-of-the-art processes, emerging technologies, and future prospects

Abstract

Recycling spent lithium-ion batteries (LIBs) and efficiently extracting high-value-added metal ions (e.g., Li⁺) hold significant strategic importance for alleviating resource shortages and promoting carbon neutrality in the energy storage sector. However, current recycling methods for spent LIBs still face key issues such as difficulty in disassembly, high energy consumption, and significant environmental pollution. Meanwhile, direct regeneration methods for LIBs remain relatively scarce. This review aims to systematically discuss and analyze the recycling and regeneration technologies of lithium-ion batteries (LIBs). For the recycling technologies, safety hazards are eliminated through physical or chemical discharge in the pretreatment stage. The core recycling technologies including pyrometallurgy, hydrometallurgy, and biohydrometallurgy have been summarized. Additionally, this review also covers the recently emerging technologies such as photocatalytic metallurgy, biomass processing, and electrochemical methods for recycling. For the extraction of valuable metals, techniques such as precipitation, electrodeposition, and the hydrogel method enable efficient separation and purification, which have been evaluated according to the recycling efficiency and environmental impacts. Besides, this review also discusses the direct regeneration of LIBs as well as the derivative applications, such as catalysts, other ion batteries, and capacitors. Finally, future challenges, including material heterogeneity, balancing regeneration efficiency and cost, improving regulatory systems, green battery design, and data-driven recycling, are discussed. This review outlines pathways for upgrading LIB recycling and regeneration through technological innovation and system improvement, so as to achieve resource circulation and sustainable development.