Bridging the gap between manganese oxide precursor synthesis and lithium manganese oxide cathodes for high-voltage lithium-ion batteries†

The synthesis route of a cathode material is pivotal in developing and optimizing materials for high-performance lithium-ion batteries (LIBs). The choice of the starting precursor, for example, critically influences the phase purity, particle size, and electrochemical performance of the final cathode. In this work, we established a direct link between MnO₂ precursor properties and the performance of LiMn₂O₄ cathodes (LMO) synthesized via a simple one-step solid-state method. By employing permanganate reduction, we synthesized MnO₂ with controlled nanoparticle growth kinetics and crystallization pathways. These tailored MnO₂ precursors were thoroughly characterized and tested as manganese precursors for LMO synthesis. Interestingly, the precursor's structural properties and oxidation states directly impacted the solid-state reaction and spinel structure formation. Operando Accelerating Rate Calorimetry (ARC) and operando XRD also highlighted the thermal and structural stability with the cycling performance of these LMO cathodes. Our findings provide valuable insights for optimizing LMO synthesis to enhance stability and performance in next-generation eco-friendly energy storage technologies.