锂离子电池中电沉积锡镍合金电极的嵌锂性能

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Ni，Sn2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．

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

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. Ni_3Sn_2 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.