Electrochemical Performance and ex situ Analysis of ZnMn₂O₄ Nanowires as Anode Materials for Lithium Rechargeable Batteries

One-dimensional ZnMn₂O₄ nanowires have been prepared and investigated as anode materials in Li rechargeable batteries. The highly crystalline ZnMn₂O₄ nanowires about 15 nm in width and 500 nm in length showed a high specific capacity of about 650 mAh·g^-1 at a current rate of 100 mA·g^-1 after 40 cycles. They also exhibited high power capability at elevated current rates, i.e., 450 and 350 mAh·g^-1 at current rates of 500 and 1000 mA·g^-1, respectively. Formation of Mn₃O₄ and ZnO phases was identified by ex situ X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies after the initial discharge-charge cycle, which indicates that the ZnMn₂O₄ phase was converted to a nanocomposite of Mn₃O₄ and ZnO phases immediately after the electrochemical conversion reaction.