Preprocessing of spent lithium-ion batteries for recycling: Need, methods, and trends

Recycling lithium-ion batteries (LIBs) has gained prominence in the last decade due to increasing supply chain constraints for critical materials (such as lithium and cobalt) and policy shift toward increased circularity of materials to mitigate environmental concerns. Conventional recycling methods (e.g., pyrometallurgical techniques) are suboptimal because of high-temperature (>1400 °C) processing with recovery yields ranging from 50% to 85%. On the other hand, optimal preprocessing/pretreatment of end-of-life (EoL) LIBs results in a) high (>90%) recovery yield, b) lower temperature processing (lower environmental footprint), c) high potential for commercial returns of materials, and d) lower safety risks. This paper reviews major preprocessing methods, including sorting, stabilization, dismantling and comminution, and separation for spent LIBs. The capabilities of major recycling firms and preferences for preprocessing in recycling methods are also reviewed, highlighting research and development (R&D) initiatives to allow more efficient and cleaner solutions for recycling spent LIBs. The industry-wide state-of-the-art recycling process is also detailed based on global practices, focusing on the highest yields and lowest environmental footprint. Finally, this paper provides policy recommendations to enable sustainable recycling of LIBs on a global scale, consequently reducing the environmental Impact of waste material and addressing the growing need for LIBs as a result of the increased demand for electric vehicles and stationary storage.