3D flower-like MnCO3 microcrystals: evolution mechanisms of morphology and enhanced electrochemical performances

•3D flower-like MnCO3 microcrystals have been synthesized with the addition of Na3Cit.•The influences of reaction time and dosage of Na3Cit on the morphology of MnCO3 microcrystals were investigated.•A mechanism for the morphology evolution of 3D flower-like MnCO3 microcrystals were proposed.•The 3D flower-like MnCO3 microcrystals exhibit the significantly enhanced cycling performance.•This work provide valuable insight into the researches on the formation mechanism for inorganic compounds.

3D flower-like MnCO3 microcrystals have been prepared via a facile hydrothermal method with the addition of sodium citrate (Na3Cit). The microstructures of the prepared microcrystals were characterized through X-ray diffraction (XRD), scanning electron microscope (SEM), thermogravimetric analysis (TGA), fourier transform infrared spectroscopy (FTIR) and N2 adsorption. Moreover, a mechanism for the morphology evolution of 3D flower-like MnCO3 microcrystals was also discussed in detail. Using the obtained 3D flower-like MnCO3 microcrystals as anode for lithium ion batteries and a series of tests including charge-discharge test, cycling ability, rate performances, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were carried out. The results show that 3D flower-like MnCO3 microcrystals can be obtained by varying the reaction time and the dosage of Na3Cit at the hydrothermal temperature of 180 °C, and the suitable hydrothermal reaction time and the dosage of Na3Cit for the 3D flower-like MnCO3 microcrystals are 12 h and 3 mmol, respectively. The electrochemical measurements indicate that 3D flower-like MnCO3 microcrystals exhibit specific capacity of 384 mAh g−1 at 0.2 C after 200 cycles, showing the significantly enhanced cycling performance than that of the obtained spherical MnCO3 microcrystals.

Graphical abstractSchematic illustration for the possible formation mechanism of 3D flower-like MnCO3 microcrystals.Download high-res image (178KB)Download full-size image