An unprecedented flood of end-of-life cells is being produced by the exponential expansion of lithium-ion battery (LIB) deployment across electric mobility, portable electronics, and stationary storage. Within the next ten years, this wave is expected to reach millions of tons yearly. Recovering the anode and cathode active materials from this spent-battery stream is central to closing the loop on critical raw materials such as lithium, cobalt, nickel, manganese, and graphite, and to decoupling battery manufacturing from primary mining. This review provides an integrated assessment of the technological, economic, environmental, and regulatory landscape of anode and cathode recovery from spent LIBs. We first summarize the current industrial status of LIB recycling and the structural limitations of conventional pyrometallurgical smelting, motivating the shift toward hydrometallurgical, direct-regeneration, and cathode-upcycling routes that preserve rather than destroy the crystalline architecture of active materials. We then examine how artificial intelligence is beginning to reshape battery sorting, disassembly, and circular manufacturing, and how digital twins are enabling intelligent, self-optimizing recycling plants. Techno-economic and life-cycle assessments are synthesized to compare the cost structures, profitability, and greenhouse-gas footprints of pyrometallurgical, hydrometallurgical, and direct-recycling pathways, and the evolving policy landscape anchored by the EU Battery Regulation (EU) 2023/1542 is reviewed as a driver of circularity. Finally, persistent research gaps spanning graphite anode regeneration, black-mass heterogeneity, solid-state and sodium-ion battery recyclability, and standardization are identified, and a future outlook is offered for a resilient, low-carbon, circular battery materials economy.