Optimizing the Electrodialysis Process for High-Efficiency Lithium Recovery from Lithium Secondary Battery Process By-products

Recently, the demand for lithium has increased due to the rapid increase in the eco-friendly electric vehicle and energy storage system industry, and the waste liquid generated during the lithium secondary battery manufacturing process contains about 5000 ppm of lithium. Lithium contained in waste liquid is about 20 times greater than that contained in general seawater. In the case of general process waste, it cannot be reused immediately. But it can be recycled through the water treatment process. Among the various recycling processes, the electrodialysis recycling process uses electrical energy. Therefore, it is an eco-friendly water treatment method that can perform lithium concentration and desalination of lithium waste liquid and simultaneously treat purified water and lithium. In this paper, the electrodialysis optimal process conditions for lithium-containing waste liquids generated during the lithium secondary battery manufacturing process were confirmed. Variables input to the electrodialysis optimal process were combined using the Minitab program, and the individual effects and importance of each reaction were confirmed through Minitab. Analysis result values were identified as the desirability of the multi-response system. The optimization of the process was carried out using a design of experiments method and was performed and analyzed under three conditions: a concentration process, a desalination process, and a concentration and desalination process.