A Comprehensive Evaluation Framework for Lithium Iron Phosphate Cathode Relithiation Techniques: Balancing Production Costs, Electrochemical Performance, and Environmental Impact

Lithium iron phosphate (LFP) has found many applications in the field of electric vehicles and energy storage systems. However, the increasing volume of end-of-life LFP batteries poses an urgent challenge in terms of environmental sustainability and resource management. Therefore, the development and implementation of efficient LFP battery recycling methods are crucial to address these challenges. This article presents a novel, comprehensive evaluation framework for comparing different lithium iron phosphate relithiation techniques. The framework includes three main sets of criteria: direct production cost, electrochemical performance, and environmental impact. Each criterion is scored on a scale of 0–100, with higher scores indicating better performance. The direct production cost is rated based on material costs, energy consumption, key equipment costs, process duration and space requirements. Electrochemical performance is assessed by rate capability and cycle stability. Environmental impact is assessed based on CO₂ emissions. The framework provides a standardized technique for researchers and industry professionals to objectively compare relithiation methods, facilitating the identification of the most promising approaches for further development and scale-up. The total average score across the three criterion groups for electrochemical, chemical, and hydrothermal relithiation methods was approximately 60 points, while sintering scored 39 points, making it the least attractive relithiation technique. Combining approaches outlined in publications with scores exceeding 60, a relithiation scheme was proposed to achieve optimal electrochemical performance with minimal resource consumption and environmental impact. The results demonstrate the framework's applicability and highlight areas for future research and optimization in lithium iron phosphate cathode recycling.