LiMn2O4 rods as cathode materials with high rate capability and good cycling performance in aqueous electrolyte

• LiMn2O4 rods were synthesized by a modified solid-state reaction method.
• LiMn2O4 rods exhibit high rate capability in Li2SO4 aqueous electrolyte.
• LiMn2O4 rods exhibit good cycling performance after 200 cycles.

The aqueous lithium–ion batteries using LiMn2O4 as cathode materials are considered to be one of the most promising stationary power sources for large-scale energy storage devices. In the present work, LiMn2O4 rods were successfully synthesized by using hydrothermal reaction to produce β-MnO2 rods as precursor followed by its solid-state lithiation. The influences of the solid-state reaction conditions on the final products were investigated and the electrochemical performances were tested in Li2SO4 aqueous electrolyte. The results show that LiMn2O4 rods can be obtained at 700 °C for 8 h (Sample A) and at 900 °C for 3 h (Sample B), respectively. Sample A exhibits superior electrochemical performances. The discharge capacities are 92.5, 92.9, 93.5 and 96.8 mAh g−1 at 1000, 500, 200 and 100 mA g−1, respectively. They are nearly constant between the high current density of 1000 and 200 mA g−1, demonstrating its high rate capability. In addition, sample A exhibits good cycling performance with only a total capacity loss of 5.4% after 200 cycles.