Abstract: The global importance of lithium-ion batteries (LIBs) has been increasingly underscored with the advancement of high-performance energy storage technologies. However, the end-of-life of these batteries poses significant challenges from environmental, economic, and resource management perspectives. This review paper focuses on the pyrometallurgy-based recycling process of lithium-ion batteries, exploring the fundamental understanding of this process and the importance of its optimization. Centering on the high energy consumption and emission gas issues of the pyrometallurgical recycling process, we systematically analyzed the capital-intensive nature of this process and the resulting technological characteristics. Furthermore, we conducted an in-depth discussion on the future research directions to overcome the existing technological barriers and limitations. This review will provide valuable insights for researchers and industry stakeholders in the battery recycling field.