Nanostructured Zn-based composite anodes for rechargeable Li-ion batteries

Abstract

The mechanism of the electrochemical reaction of Zn with Li was investigated by ex situ X-ray diffraction (XRD) analysis combined with a differential capacity plot of the Zn electrode at a low current of 10 mA g⁻¹. The pure Zn electrode showed a high reactivity with Li, with first discharge and charge capacities of 574 and 351 mA h g⁻¹, respectively. In addition, Zn–C and Zn–Al₂O₃–C composites prepared by simple high-energy mechanical milling were evaluated for use as anode materials in rechargeable Li-ion batteries. The Zn–C nanocomposite was composed of nanosized Zn in an amorphous C matrix, while the Zn–Al₂O₃–C nanocomposite (obtained by the mechanochemical reduction of ZnO and Al) was composed of nanocrystalline Zn and amorphous Al₂O₃ in the amorphous C matrix. Electrochemical tests showed that the Zn–Al₂O₃–C nanocomposite electrode exhibited a high volumetric capacity of more than 1800 mA h cm⁻³ over 100 cycles.