Solid-State Synthesis of Na and Al Co-doped Lithium Manganese Spinel Cathode Material

In this study, LMO-xNa and LNMO-yAl were synthesized by a simple high-temperature solid-phase method. MnO2, Li2CO3, NaOH, and Al2O3 were used as manganese source, lithium source, sodium source and aluminum source, respectively. The effects of Na doping and Na, Al co-doping on the electrochemical performance and crystal structure of spinel LiMn2O4 materials were explored, and the crystal parameters and cycle performance of the co-doped materials were discussed emphatically. Through the discussion of SEM, XRD, EIS curve, cycle curve and the performance of the first charge and discharge cycle, it was concluded that when the Na doping ratio x = 0.15 and the Al doping ratio y = 0.10, the reversible cycle capacity of the material maintained is as high as 95%, and the first discharge capacity reaches 125.5 m Ah g–1. It can be seen that the Na, Al co-doped LNMO-yAl not only maintains a certain discharge capacity and has a higher capacity retention rate, it is a promising cathode material for lithium-ion batteries.