Effect of Mn3O4 particle size on synthesis and electrochemical performance of spinel LiMn2O4 cathode

Abstract

Spinel LiMn₂O₄ has emerged as a highly promising cathode material for large-scale applications in lithium-ion batteries. The physicochemical properties of LiMn₂O₄, particularly particle size, specific surface area and crystallinity, play crucial roles in determining electrode kinetics and electrochemical performance. In this study, spherical Mn₃O₄ particles with controlled sizes were synthesized through a metallic manganese corrosion-oxidation method, which subsequently served as manganese precursors for preparing LiMn₂O₄ with different particle sizes. The effects of particle size on the structural characteristics and electrochemical properties of LiMn₂O₄ were systematically investigated. The results demonstrate that the spherical LiMn₂O₄ synthesized from smaller Mn₃O₄ particles (median particle size D₅₀ = 3.33 μm) exhibits enhanced structural stability, reduced electrochemical impedance, and improved lithium-ion diffusion coefficient, leading to remarkable improvement in lithium storage properties. Specifically, this optimized material delivers specific discharge capacities of 126.51 mAh/g at 1 C and 105.01 mAh/g at 10 C under 25 °C. Moreover, it exhibits a capacity retention rate of 83.76% after 400 cycles at 1 C and 25 °C, indicating stable long-term performance. These findings reveal that the particle size of Mn₃O₄ significantly influences the structural and electrochemical properties of LiMn₂O₄, providing valuable guidance and practical pathways for synthesizing high-performance lithium manganese oxide cathode materials.