Efficient and Sustainable: Direct Electrochemical Recovery of Lithium from Spent LiFePO4Batteries

Abstract

One of the most significant challenges for resource conservation and sustainable energy development is the separation of lithium from spent lithium-ion batteries. In this study, a simple and cost-effective direct electrochemical approach was employed for recovering lithium from spent LiFePO4batteries using a chemometric approach. A two-step process was applied to recover Li from the spent LiFePO4batteries. The process begins with the leaching of lithium into the Na2SO4electrolyte solution, followed by the precipitation of lithium as Li3PO4in a subsequent step. The electrochemical leaching conditions for lithium were investigated through a face-centered central composite experimental design. The leaching efficiency and selectivity of lithium were achieved at about 92 and 96%, respectively. The selectivity of the process was confirmed by scanning electron microscopy with energy dispersive X-ray spectroscopy and inductively coupled plasma optical emission spectroscopy analysis, which clearly showed that the other metals remained nearly constant prior to as well as following the leaching process. Furthermore, the X-ray diffraction and inductively coupled plasma optical emission spectroscopy analysis verified the precipitation and purity efficacy of recovered Li3PO4, which were 89 and 99%, respectively. The direct electrochemical lithium recovery from lithium-ion batteries could offer higher efficacy compared to the conventional hydrometallurgical lithium recovery, which involves several separation steps for impurity elements. This efficient and flexible approach signifies a notable advancement in purification and separation technology, providing an eco-friendly solution for lithium recovery from spent lithium-ion batteries. This study introduces a viable approach for developing a recycling process for spent lithium-ion batteries that aligns with the ultimate goal of achieving carbon neutrality.