RecyclingRecycling lithiumLithium-ionLithium-ion battery batteriesBattery (LiBs)LIB batteries from electric vehicles (EVs) is essential for sustainabilitySustainability, environmental protection, and a circular economyCircular economy, given the increasing amount and complexity of cell chemistries and the variety of binders used. With the growing popularity of lithium iron phosphateLithium iron phosphate (LFP) batteriesBattery, which present an economic challenge in conventional recyclingRecycling in sole processing, and the application of mixed cathode materials, there is a demand for flexible processing methods. This study explores the synergistic effects of spent LFP-NMCNMC blackLFP-NMC mixing mass mixtures, focusing on leachingLeaching time, sulfuric acid concentration, and the molar ratio of the mixtures. The objective is to demonstrate a more environmentally friendly and straightforward approach to processing LFP and NMCNMC black mass without the need for external reducing agents, oxidants, or thermal pre-treatment. The optimized mixture is leached to recover critical batteryBattery metals efficiently. Ultimately, a flexible hydrometallurgical recyclingRecycling process is developed and validated.