Abstract Lithium iron phosphate (LiFePO 4 , LFP) batteries are widely used in power and energy storage applications, yet their impending retirement poses significant challenges for resource sustainability and environmental protection. The evolution of LFP recycling reflects a paradigm shift from element recycling to structural reconstruction and ultimately to functional upgrading. This review systematically discusses the recycling, regeneration, performance evaluation, and high-value utilization of spent LFP (S-LFP) cathode materials. Current recycling methods include hydrometallurgy and pyrometallurgy, both of which face limitations such as high chemical consumption, energy intensity, and environmental impact. In comparison, direct regeneration techniques, such as solid-phase, molten salt, hydrothermal, and electrochemical regeneration, offer more promising pathways by repairing lattice defects and restoring electrochemical properties with lower energy input. Among these, molten salt regeneration enhances lithium-ion diffusion and reduces repair temperature, representing a key research focus. Furthermore, converting regenerated LFP into high-value materials like sodium-ion battery cathodes, catalysts, or functional composites significantly improves economic viability. However, industrial-scale implementation remains hindered by high costs, material variability, and the lack of standardized evaluation and closed-loop supply chains. Future efforts should prioritize green low-energy recycling systems, multi-mechanism synergistic regeneration, standardized assessment protocols, and precision conversion strategies to advance the sustainable and high-value recycling of S-LFP batteries.
Chen et al. (Sun,) studied this question.