Recycling of Spent Lithium‐Ion Batteries in View of Lithium

The growing demand for lithium‐ion batteries (LIBs) has intensified the need for sustainable lithium sources, as natural reserves struggle to meet global requirements. Spent LIBs, rich in lithium, present a promising alternative for lithium extraction, providing both environmental and economic benefits. This review underscores the significance of lithium recycling and systematically examines recent advances in extraction processes, focusing on the extraction of lithium salts from spent cathode and anode materials, while addressing key challenges such as impurity control. Further, innovative lithium reintegration pathways, particularly direct regeneration methods utilizing carbonate salts are reviewed. By broadening the scope of extracted lithium compounds beyond conventional carbonates, how expanding extraction media can enhance the feasibility of a closed‐loop lithium supply is demonstrated. The proposed “lithium extraction‐reintegration” framework not only improves resource circularity but also establishes a foundation for securing lithium in the battery economy. This review aims to inspire future research and industrial efforts toward closing the lithium supply loop, bridging critical gaps in sustainable battery material recovery.