Tetragonal Zinc Diphosphide and Its Nanocomposite as an Anode for Lithium Secondary Batteries

Tetragonal zinc diphosphide (ZnP2) and its nanocornposite (ZnP2/C) were prepared using commercially available amorphous red phosphorus and zinc powder by high energy mechanical milling (HEMM) at ambient temperature and pressure. The ZnP2/C nanocomposite was composed of uniformly distributed, nanosized, ZnP2 crystallites in the amorphous carbon matrix, as confirmed with X-ray diffraction (XRD) and high resolution transmission electron microscope (HRTEM) analyses. The electrochemical reaction mechanism of the ZnP2/C nanocomposite with lithium was investigated during the first cycle. Electrochemical tests showed that the ZnP2/C nanocomposite exhibited enhanced electrochemical reversibility, good cyclability, and high-rate capability when cycled between 0.55 and 2 V.