Review on hydrometallurgical recovery of valuable metals from spent lithium-ion batteries

With the development of the new energy vehicles industry, the number of spent lithium-ion batteries has increased sharply. The recovery of valuable metals from spent lithium-ion batteries can effectively alleviate the dependence on foreign countries for important strategic metals (Ni, Co, Mn, Li, et al.), as well as reducing resource waste and environmental pollution. Hydrometallurgical recovery is considered to be the most suitable recycling technology among the many recycling technologies. This paper introduces the leaching process of hydrometallurgy technology for battery recycling and summarizes different types of leaching agents and their advantages and disadvantages. A combination of H2SO4 and H2O2 to recycle valuable metals is believed to be a relatively mature recycling process at this stage due to its high recovery rate, fast reaction rate, no secondary pollution and low requirements for equipment corrosion resistance. The latest research progress on leaching valuable metals using deep eutectic solvents (DESs) in our group is also introduced. The research direction and main focus for the recycling of spent lithium-ion batteries in the future are put forward. We dedicate this review to academician Qingru Chen to express our respect for his lifelong research contributions to advancing the field of mineral processing, especially in the fundamental research and technological development of dry coal preparation.