锂离子电池中电沉积锡镍合金电极的嵌锂性能

Lithium insertion properties of electrodeposited Sn-Ni alloy electrode in lithium-ion battery

为获得具有更高比容量的锂离子电池负极材料,通过电沉积方法制备了Sn-Ni合金电极. 对合金镀层组成与形貌进行了表征,测试了电极的电化学性能. 电沉积Sn-Ni合金电极是Ni3Sn2 和Sn复合电极,电极中Sn与Ni的摩尔比为 1: 1 .15,电极首次放电容量可达 500mAh/g,库仑效率 88%,前 10次循环库仑效率都在 98%以上, 50次循环时放电容量仍可达 350mAh/g,库仑效率在 94%以上. 循环伏安和微分容量曲线都表明,多次循环后的电极完全表现出电沉积Sn电极的特征. 扫描电镜照片表明,循环后的Sn-Ni合金电极发生了严重的膨胀和破裂.

In order to obtain anode material of lithium-ion battery with higher specific capacity, Sn-Ni alloy electrode was prepared by electrodeposition. The composition and morphology of alloy electrode were characterized and the electrochemical performance was measured. Ni3Sn2 and Sn were found in the alloy, and the ration of Sn to Ni was 1:1.15 by mol. The discharge capacity of the anode was 500 mAh/g and the coulombic efficiency was 88% for the first discharge. The coulombic efficiency was always above 98% for the first ten cycles and keep over 94% during 50 cycles. The discharge capacity of the 50th discharge was still above 350 mAh/g. The results of CVs and differential capacity plots showed that the Sn-Ni alloy electrode exhibited the characteristics of electrodeposited Sn electrode after cycles. The SEM showed that there was serious expanding and cracking after charge-discharge cycles.