Recovery of Li/Co from spent lithium-ion battery through iron-air batteries

Abstract

The widespread application of Lithium-ion Batteries (LIBs) has led to a significant increase in the number of spent LIBs. Consequently, the recycling and utilization of spent LIBs have become an inevitable choice for recovering valuable resources and protecting the environment, aligning with the principles of sustainable development. This study reports an iron air battery recycling system that is capable of recovering both Li/Co and energy from spent LiCoO₂ cathode materials and the separation reaction is completely spontaneous. Meanwhile, lithium and cobalt were successfully recovered from the powdered leach solution of spent LiCoO₂ cathode material, and it was preliminarily demonstrated that spent iron could be used as a sacrificial anode for the system. Several key parameters affecting recovery are optimized, including anode solution pH, discharge current density, and concentration of the solution to be recovered. Under the conditions of anode solution pH of 1.8, discharge current density of 0.1 mA cm⁻², and concentration of recovery solution of 0.15 mol/L, the system can be operated stably for more than 24 h, and the recoveries of Li⁺ and Co²⁺ can be up to 1.49 mg h⁻¹ and 18.75 mg h⁻¹ respectively, and the output energy can reach 75.15 kJ/mol. This research not only provides a sustainable and cost-effective method of disposing of used lithium-ion batteries, but also offers up new possibilities for the disposal of scrap iron.