Ordered Spinel LiMn2O4 as Cathode for High Performance Aqueous Energy Storage

Well-ordered nano-LiMn2O4 is successfully prepared. The preparation follows two steps: synthesis of oval MnCO3 by hydrothermal reaction and preparation of LiMn2O4 through sol-gel route. The as-prepared LiMn2O4 preserves cubic spinel morphology and consists of uniform particles with a diameter of similar to 200 nm. It exhibits an excellent electrochemical performance in aqueous electrolytes. A cell with the LiMn2O4 cathode and active carbon anode is fabricated. The initial discharge capacity of the cell is 119 mAh/g and it retains 88% even at the current density of 10000 mA/g. The coulombic efficiency maintains nearly 100% over 700 cycles at the current density of 5000 mA/g. Moreover, the cell could be fully charged with total time of similar to 2 min. The superior rate capability and excellent cycling stability show that the LiMn2O4 is a promising cathode material for aqueous energy storage in practical application.