Towards a closed loop recycling process of end-of-life lithium-ion batteries: Recovery of critical metals and electrochemical performance evaluation of a regenerated LiCoO2

The growing demand for lithium-ion battery technology emphasizes the critical need to establish effective recycling and proper disposal methods for used batteries, ensuring the long-term sustainability and security of the battery supply chain. This study addresses this need by exploring two hydrochemical routes, using sulfuric acid and nitric acid, respectively. The objective is to investigate the influence of the acid used in the leaching process on the properties of the regenerated final product, LiCoO2. Moreover, a novel and simplified approach for extracting lithium as lithium carbonate is proposed. In evaluating the recycled batteries, careful examination of their physicochemical properties and electrochemical performances reveals striking similarities to batteries produced from commercial sources. This comparison provides evidence of the successful recycling process. By optimizing the leaching conditions, we were able to extract more than 98% of both cobalt and lithium from the used cathode materials of cell phone batteries. Significantly, our study demonstrates that nitric acid offers a straightforward method for separating and obtaining a pure product, surpassing the outcomes achieved with sulfuric acid using the same steps. Additionally, we thoroughly investigate and compare the electrochemical performances of the synthesized cathode materials with those synthesized from pure commercial reagents. This systematic analysis confirms the effectiveness and viability of the proposed recycling process. The key advantage of this approach lies in its ability to achieve a complete recycling of the initial spent cathodic elements, which is crucial for establishing a circular economy. This comprehensive recycling method not only addresses the increasing demand for lithium-ion battery technology but also contributes to the sustainable utilization of resources and the preservation of the battery supply chain's integrity.