Ascorbic-acid-assisted recovery of cobalt and lithium from spent Li-ion batteries

Recycling of the major components from spent Li-ion batteries (LIBs) is considered desirable to prevent environmental pollution and recycle valuable metals. The present work investigates a novel process for recovering Co and Li from the cathode materials (containing LiCoO2 and Al) by a combination of ultrasonic washing, calcination, and organic acid leaching. Copper can also be recovered from the anode materials after they are manually separated from the cathode. Ascorbic acid is chosen as both leaching reagent and reducing agent to improve the Co recovery efficiency. Leaching efficiencies as high as 94.8% for Co and 98.5% for Li are achieved with a 1.25 mol L−1 ascorbic acid solution, leaching temperature of 70 °C, leaching time of 20 min, and solid-to-liquid ratio of 25 gL−1. The acid leaching reaction mechanism has been preliminarily studied based on the structure of ascorbic acid. This method is shown to offer an efficient way to recycle valuable materials from spent LIBs, and it can be scaled up for commercial application.