Recently, due to the rapid growth of the lithium-ion battery(LIB) industry and the significant increase in waste LIB generation, the LIB recycling business has garnered global attention. The recycling of waste LIBs holds paramount importance as it facilitates resource circulation by reusing precious and valuable metals like Mn, Co, Ni, and Li contained within batteries, thereby preventing environmental pollution. In this study, we aim to introduce a technology that utilizes a hydrometallurgical process to separate and recover Mn, Co, Ni, Li, and other materials from the black mass generated after pretreating waste LIBs. Specifically, we will analyze instances of solvent extraction technology application, which serves as the core technology in the separation process. We will elucidate efficient process design methods and provide an overview of potential future eco-friendly technologies poised to capture attention.