The cathode performance of lithium-ion batteries (LIBs) fabricated from recycled cathode active materials is studied for three scenarios. These scenarios are based on the conditions for separation of different cathode active materials in recycling facilities during the LIB’s recycling process. In scenario one, the separation process is performed ideally, and the obtained pure single cathode active material is used to make new LIBs after regeneration. In scenario two, the separation of active materials is performed with efficiencies of less than 100%, which is the actual case in the recycling process. In this scenario, a single cathode active material that contains a little of the other types of cathode active materials is used to make new LIBs after the materials’ regeneration. In scenario three, the separation has not been performed during the recycling process. In this scenario, all types of cathode active materials are regenerated together, and a mixture is used to make new LIBs. The studies are performed through modeling and computer simulation, and several experiments are conducted for validation purposes. The cathode active materials that are studied are the five commercially available cathodes made of LiMn₂O₄ (LMO), LiCoO₂ (LCO), LiNi_xMn_yCo_(1−x−y)O₂ (NMC), LiNi_xCo_yAl_(1−x−y)O₂ (NCA), and LiFePO₄ (LFP). The results indicate that the fabrication of new LIBs with a mixture of cathode active materials is possible when cathode active materials are not ideally separated from each other. However, it is recommended that the separation process is added to the recycling process, at least for the separation of LFP or reducing its amount in the cathode active materials mixture. This is because of the difference of the voltage level of LFP compared to the other studied active materials for cathodes.

Lithium (Li)‐ion batteries (LIBs) are extensively used in modern electronics and electric vehicles, leading to a growing accumulation of spent batteries. Improper disposal poses serious environmental and economic challenges. While most recycling efforts focus on recovering valuable metals such as Li, cobalt (Co), and nickel (Ni) from cathodes, the anode material—primarily graphite—is often overlooked and discarded, contributing to resource inefficiency. In this study, a practical and sustainable method was developed to recover and regenerate anode graphite from mixed spent LIBs containing diverse chemistries, including Li Co oxide (LCO), Li iron phosphate (LFP), LMO, Ni manganese Co oxide (NMC), and NCA. A density‐based separation technique, based on Stokes’ law, was employed to isolate graphite from cathode residues. The separation efficiency was confirmed through scanning electron microscopy (SEM) and energy‐dispersive X‐ray spectroscopy (EDX), both of which revealed a clean and complete separation of graphite. Structural analysis using X‐ray diffraction (XRD) showed sharp diffraction peaks at (002), (100), and (004) planes, indicating high crystallinity and minimal lattice degradation during processing. The recovered graphite was subjected to thermal treatment and evaluated through galvanostatic cycling. The regenerated anode material exhibited a specific capacity of 340 mAh/g, closely matching that of commercial graphite (342 mAh/g), confirming excellent electrochemical performance. These findings demonstrate the viability of regenerating anode materials from mixed battery waste and underscore its role in reducing environmental impact, conserving critical raw materials, and enhancing the sustainability of LIB recycling systems.