Electrode properties and lithiation/delithiation reactions of Ag-Sb-Sn nanocomposite anodes in Li-Ion batteries

Based on the mechanical alloying technique and expedient microstructural design, the Ag52-xSbxSn48 system has been established as a promising candidate of anode materials in Li-ion batteries. The half-cell tests revealed that the Ag36.4Sb15.6Sn48 electrode with a heterophase structure involving SnSb, Ag3Sn, and Sn was capable of maintaining a rechargeable capacity as high as 380 mAh/g over 300 cycles when cycled in a proper organic electrolyte between 0.0 and 1.0 V (vs. Li) under a constant current density of 0.2 mA/cm2. The analysis for the structural changes of the electrode during cycling indicated that the superior cycling performance of the Ag36.4Sb15.6Sn48 electrode was attributable to the presence of the structurally stable intermetallic compounds of SnSb and Ag3Sn in the host structure, the stepwise lithiation/delithiation mechanisms, and the AgLi2Sn-oriented phase transformations. In addition to the phase structure of the alloy, which essentially affected the cycling stability of the alloy electrode, the effects of different organic electrolytes on the cycling performance were also examined.