Effect of Microstructures on Charge-Discharge Performance of the Mechanically Alloyed Ag_(52)Sn_(48) Powders as an Anode Material for Lithium-Ion Batteries

摘要

Ag_(52)Sn_(48) alloy powders, as a new anode material of the lithium-ion battery, were prepared by a technique of mechanical alloying (MA). Phases, microstructures and morphologies of the Ag_(52)Sn_(48) alloy powders milled for various times were investigated by XRD and SEM. And, the charge/discharge performances of the simulated test cells were also evaluated, using the Ag_(52)Sn_(48) alloy powders milled for time range from 45 h to 65 h as the anode materials. The results show that the milled Ag_(52)Sn_(48) alloy powders consist of two phases of Sn and Ag_3Sn. As increasing the milling time, the Ag_3Sn/Sn powders are gradually in a nanocrystalline/amorphous state, respectively, and the milled powders are finer and more spheroidic, and pompon-like in shape. The initial discharge capacity of the cell, using the 65 h milled Ag_(52)Sn_(48) alloy powders as the anode material, is as high as 800 mAh·g~(-1) with an excellent cycling performance. It was determined that the microstructures of the Ag_(52)Sn_(48) alloy powders had a great influence on the charge/discharge performance of the lithium-ion batteries.