锂电池硅锡合金负极的电沉积制备

Electrodeposition of Si-Sn Alloy Anode for Lithium-Ion Batteries

采用恒电位共沉积方法从有机溶剂中制备不同Sn含量的Si-Sn合金负极,在100 mA/cm2的电流下进行100次充放电循环后,仍具有0.151 mAh/cm2的高面积比容量,比Si负极提升了73%。X射线衍射结果表明Si-Sn合金中Sn为β-Sn,Sn颗粒的嵌入不仅使Si-Sn合金负极比电沉积Si负极具有更好的导电性,提升了单位面积Si、Sn的沉积量;而且缓解了非晶Si的体积效应,从而提高了循环性能。不同Sn含量的容量曲线表明5%Sn含量的Si-Sn合金比容量最高,在500次循环后仍能保持859 mAh/g。

Si-Sn alloy anodes with different proportion of Sn is prepared by constant potential co-deposition method from organic solvents. After 100 charge and discharge cycles at a current of 100 mA/cm2,its large capacity is able to attain 0.151 mAh/cm2,73% higher than Si anode. X-ray diffraction results show that Sn in the Si-Sn alloy is β-Sn. Sn particles embedded Si anode has a lower resistance than Si composite anode,which enhances the deposition amount of Si and Sn;the Sn particles stabilizes the amorphous Si which improves cycle performance. The capacity curves of different proportion of Sn show that the Si-Sn alloy with 5% Sn has the highest specific capacity(859 mAh/g)after 500 cycles.