High-Value Recycling and Regeneration of Spent LiFePO4 Batteries: Recent Advances, Mechanisms, and Perspectives

Abstract

The rapidly growing deployment of electric vehicles and energy storage systems is generating increasing quantities of spent LiFePO₄ (LFP) batteries and creating an urgent need for environmentally sound and economically viable recycling. Compared with Ni- and Co-rich cathodes, spent LFP has a lower intrinsic resource value, which reduces the profitability of conventional pyrometallurgical and hydrometallurgical routes and limits their suitability for closed-loop utilization. This review summarizes recent advances in the high-value recycling and regeneration of spent LFP batteries, with an emphasis on retirement trends, degradation mechanisms, recycling challenges, and advanced regeneration strategies. Conventional pyrometallurgical and hydrometallurgical recovery routes are first compared in terms of efficiency, cost, environmental burden, and scalability. Recent progress in direct regeneration is then discussed, including lithium replenishment, lattice repair, carbon-coating reconstruction, hydrothermal treatment, and molten-salt-assisted regeneration. Upgraded regeneration strategies, including defect modulation, doping, surface engineering, micro/nanoscale structural optimization, cross-system conversion, and transformation into multifunctional materials, are also highlighted. Finally, key barriers associated with feedstock heterogeneity, impurity control, process economics, environmental sustainability, and industrial standardization are identified. This review provides systematic insights into green, scalable, and value-added recycling pathways for spent LFP batteries.