Zinc Telluride as Electrochemical Storage Material for High-Performance Sodium-Ion Batteries

High-energy ball milling (HEBM) is used to synthesize zinc telluride (ZnTe) and amorphous C (ZnTe-C) nanocomposites as novel anode materials for sodium-ion batteries (SIBs). A nanostruc-tured ZnTe-C composite is prepared using Zn, Te, and acetylene black as precursor materials via a facile two-step HEBM process. The initial HEBM of Zn and Te induces the formation of the ZnTe alloy nanostructure via a mechanochemical reaction. The subsequent HEBM process generates the ZnTe composite embedded in amorphous C (ZnTe-C), as confirmed using X-ray diffraction, transmission electron microscopy, and element mapping analyses. When used as SIB anode, the ZnTe-C composite exhibits good cyclic life (specific discharge capacities of 383 mAh g^-1 at 0.1 A g^-1 over 150 cycles and 373 mAh g^-1 at 0.5 A g^-1 after 500 cycles) and excellent rate capability (89% capacity retention at 10 A g^-1 relative to that at 0.1 A g^-1). The impedance analysis and ex situ scanning electron microscopy results reveal that the properties of ZnTe-C are superior to those of ZnTe because C serves as buffering matrix that suppresses the volume changes in ZnTe during alloying/dealloying and reduces the charge transfer resistance. The ZnTe-C nanocomposite in this study is a promising candidate for high-performance SIB anodes.