Electrochimica Acta, Vol.251, 119-128, 2017
3D flower-like MnCO3 microcrystals: evolution mechanisms of morphology and enhanced electrochemical performances
3D flower-like MnCO3 microcrystals have been prepared via a facile hydrothermal method with the addition of sodium citrate (Na(3)Cit). 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 N-2 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 Na(3)Cit at the hydrothermal temperature of 180 degrees C, and the suitable hydrothermal reaction time and the dosage of Na(3)Cit 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. (C) 2017 Elsevier Ltd. All rights reserved.
Keywords:3D flower-like;MnCO3 microcrystals;Hydrothermal synthesis;Evolution mechanisms of morphology;Electrochemical performances