Deep eutectic solvents for high-efficiency and short-process recycling of spent lithium-ion batteries: progress, challenges, and perspectives

The rapid expansion of the electric vehicle and energy storage sectors has driven unprecedented demand for sustainable recycling of spent lithium-ion batteries (LIBs). Conventional recycling technologies such as pyrometallurgy and hydrometallurgy typically suffer from high energy consumption, environmental pollution, and lengthy workflows. Recently, deep eutectic solvents (DESs) have gained considerable attention for resource recovery due to their potential to enable a green, efficient, and short-process recycling route. Nevertheless, the practical application of DESs still faces considerable scepticism, owing to their dependence on high temperatures, low solid-to-liquid (S/L) ratios, and high costs. In this review, we focus on the intrinsic properties of DESs and the key mechanisms governing their role in metal recovery and material regeneration. Building on this, we provide perspectives on future development spanning DES design, characterization techniques, expansion application, techno-economic and environmental assessment, policy incentives and industrial compatibility. These insights aim to clarify the current trends in the application and development of DESs for spent battery recycling, while identifying future directions for their practical utilization. This journal is © The Royal Society of Chemistry, 2026.