Synthesis and electrochemical properties of Li-rich spinel type LiMn 2O 4 powders by spray pyrolysis using aqueous solution of manganese carbonate

Abstract

Li-rich lithium manganese oxide (Li 1.09Mn 1.91O 4) powders were prepared by spray pyrolysis using an aqueous solution of manganese carbonate. The aqueous solution, in which manganese carbonate was uniformly dispersed by a surfactant, was used as the starting solution. As observed by scanning electron microscopy, Li 1.09Mn 1.91O 4 had spherical morphology with a porous microstructure and consisted of primary particles. Powder X-ray diffraction analysis revealed that the crystal phase of the Li 1.09Mn 1.91O 4 powders was in good agreement with the spinel phase. Inductively coupled plasma analysis showed that the molar ratio of Li and Mn in the Li 1.09Mn 1.91O 4 powders was 1.09:1.90. Through electrochemical measurements, the initial discharge capacity of a Li 1.09Mn 1.91O 4 cathode was found to be 107 mAh/g at 1 C (99% retention after 100 cycles) and 91 mAh/g at 10 C (93% retention after 100 cycles). The retention ratio of discharge capacity remained greater than 90%, although capacity loss was observed up to 20 cycles. The Li 1.09Mn 1.91O 4 cathode derived from carbonate solution had excellent cycling stability in comparison with the LiMn 2O 4 cathode derived from nitrate solution.