Sodium dodecyl sulfate (SDS)-assisted preparation of homogeneous monodisperse MnCO3 microspheres and its application to the synthesis of LiMn2O4

In recent years, there has been increasing interest in the morphological design of lithium manganese oxide (LiMn2O4), but little attention has been paid to the agglomeration and mono-dispersion characteristics of the particles. In the present study, a facile co-precipitation method was used to synthesize manganese carbonate (MnCO3) microspheres. Their effects on the dispersion of microspheres were investigated by introducing three different types of surfactants: anionic sodium dodecyl sulfate (SDS), cationic hexadecyl trimethyl ammonium bromide (CTAB), and nonionic polyethylene glycol (PEG). The extent of MnCO3 dispersion was analyzed by scanning electron microscopy (SEM) and laser particle size analysis. The results demonstrated that the addition of 50 wt% SDS enabled the effective synthesis of homogeneous monodisperse MnCO3 microspheres with superior tap density. Additionally, LiMn2O4 cathode material was synthesized by solid-phase sintering utilizing spherical MnCO3 as the template. Electrochemical tests indicated that the homogeneous monodisperse LiMn2O4 exhibited superior electrochemical performance, with a first-cycle Coulombic efficiency of 92.29% and a specific discharge capacity of 110.73 mAh.g-1 at 5 C and 128.49 mAh.g(-1) after 100 cycles at 1 C.