Nano-sized SnSbAgx alloy anodes prepared by reductive co-precipitation method used as lithium-ion battery materials

Nano-sized SnSbAgx alloy anode materials are prepared by reductive co-precipitation method combining with the aging treatment in water bath at 80 degrees C. The microstructure, morphology and electrochemical properties of synthesized SnSbAgx alloy powders are evaluated by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), galvanostatical cycling tests and electrochemical impedance spectroscopy (EIS). The XRD results indicate that the phases are composed of beta-Sn, Sb, Ag3Sb, Ag3Sn and SnSb in the SnSbAgx alloy. The existence of inactive element Ag and the complex multi-step reaction mechanism in SnSbAgx alloy anodes are propitious to improve the structure stability and thus improve the cycling performance. When cycled at a constant current density of 0.1 mA cm(-2) between 0.1 and 1.50 V, SnSbAg alloy shows better performance that the first discharge capacity is 794 mAh g(-1) and the reversible capacity of 20th cycle attains to 327 mAh g(-1). EIS results show that the semicircle relates to the passivation on the surface in the higher frequency zone and the bias relates to the diffusion in the lower frequency zone.