The recyclingRecycling of end-of-life lithium-ion batteries (LIBs)Lithium-Ion Batteries (LIBs) is crucial for resource sustainabilitySustainability and environmental protection. With the rapidly increasing volume of spent batteries, simplified recyclingRecycling approaches based on roasting treatment and subsequent metalRecovery recoveryMetal recovery are highly desirable. In this study, the thermokineticThermokinetic analysis behavior, phase evolution, and microstructural transformations of spent commercial LiMn₂O₄ (LMO) electrodes were investigated. XRD and SEM–EDS analyses revealed that the cathode consisted of LMO coated on both sides of an Al current collector, while the anode comprised graphite coated on a Cu current collector. After heating at 50 K/min to 1000 °C and holding for 2 h under argon, LiMn₂O₄ decomposed into MnO, Li₂O, LiAlO₂, and Al₂O₃ phases. Quantitative analysis showed that of the 2.59 wt.% lithiumLithium in the treated battery, 45.48% was leached as water-soluble Li₂CO₃, while 54.52% remained in water-insoluble LiAlO₂. These results demonstrate the feasibility of a pyrometallurgyPyrometallurgy and waterLeaching leachingWater leaching combined process and emphasize the need to suppress LiAlO₂ formation for more efficient lithiumLithium recoveryRecovery.