Novel synthesis of LiMn2O4 with large tap density by oxidation of manganese powder

Research highlights: → A novel synthesis of LiMn2O4 using metallic manganese powder as starting material. → The manganese oxide precursors have high purity and large tap density. → The optimized LiMn2O4 has a large tap density of 2.66 g cm-3 and good performances. → The tap density of LiMn2O4 in this work is much larger than those of other spinels. -- Abstract: A novel synthesis of LiMn2O4 cathode has been developed using metallic manganese powder as starting material. The LiMn2O4 cathode has large tap density and high purity. The samples are characterized by TG/DTA, XRD, SEM, ICP and electrochemical measurements. The manganese oxides prepared by oxidation of manganese powder at 800 oC are identified as complex of Mn3O4 and Mn2O3, and have high purity and a large tap density of 2.92 g cm-3. All the LiMn2O4 made from manganese oxides or manganese powder exhibit the same cubic spinel phase structure. The optimized LiMn2O4 has a large tap density of 2.66 g cm-3 and good electrochemical performances with an initial discharge capacity of 119.1 mAh g-1, and a capacity retention of 89.1% at the 15th cycle.