Enhancement of lithium storage performance of ZnMn2O4 anode by optimizing hydrothermal synthesis

To explore the effect of the preparation conditions on the electrochemical properties of transition metal oxide anode materials, ZnMn2O4 anode material was hydrothermally synthesized using zinc nitrate and manganese nitrate as raw materials. The effects of reaction temperature, reaction time, compactness, and pH on the synthesis conditions were systematically studied through an orthogonal test designed with four factors and three levels. X-ray diffraction and scanning electron microscopy proved the formation of a micron-scale block-like ZnMn2O4 structure with the I41/amd space group. The Li/ZnMn2O4 cells delivered an initial discharge specific capacity of 933.1 mA·h/g, and the discharge specific capacity remained at 249.3 mA·h/g after 100 cycles at a current rate of 0.1C for the as-synthesized ZnMn2O4 under the optimized conditions. The optimized sample with orthogonal test exhibits outstanding cycle stability and rate performance.