Synthesis and electrochemical properties of ZnMn2O4 microspheres for lithium-ion battery application
The precursors of ZnMn2O4 microspheres are synthesized by a mixed solvothermal method using ZnAc2·2H2O and MnAc2·4H2O as metal source as well as urea or ammonium bicarbonate as the precipitant. The as-synthesized precursors are further heat-treated at a suitable temperature to obtain the expected compounds. The expected samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. The electrochemical properties of the sample are investigated by battery testing system. The influences of different precipitants on its structure, morphology and the electrochemical properties are discussed. The results show that the morphology of expected compound is depended on different precipitants. When tested as anode material for lithium ion battery, the ZnMn2O4 sample obtained by pyrolysis of the Zn0.33Mn0.67CO3 precursor using ammonium bicarbonate as precipitant exhibits better electrochemical properties. It has a high initial discharge specific capacity of 1269 mAhg−1 and remains its capacity at 602 mAhg−1 after 100 cycles under a constant current of 100 mAg−1 in the voltage range of 0.01-3 V. The outstanding electrochemical performances for the ZnMn2O4 microspheres suggest that it could be a promising candidate as a novel anode material for lithium ion battery applications.