锂离子在镁电极上的电沉积

Electrodeposition of Lithium Ions on Magnesium Electrode

研究了熔融氯化锂与氯化钾在摩尔比为58∶42的熔盐中,锂在镁电极上的电沉积过程。利用电化学工作站,采用循环伏安法扫描技术,考察了在450℃,扫描速度为20 mV/s时,锂在钼电极和镁电极上的析出电位,得到析出电位分别为-2.4和-2.28 V。结果说明,镁电极对于锂的析出具有诱导作用;发现在所研究的温度范围内,电流效率均大于92%;利用扫描电子显微镜考察了镁电极沉积锂前后表面形貌的变化,发现镁电极上沉积锂之后与未沉积锂前相比,表面形成了均匀致密的合金层;扫描电子显微镜能谱分析表明,合金试样中的杂质元素主要为氧,可能是由于样品放置在空气环境中所致,测量时间内引起的。

In this article, the electrodeposition of lithium ions on magnesium electrode in molten salt of KCl- LiCl（58：42, molar ratio） was studied. The deposition of lithium ions on molybdenum and magnesium electrodes was investigated by cyclic voltammograms coupled with electrochemical station at a san rate of 20 mV/s and 450 ℃, and the results showed that the deposition potential was -2.4 V and -2.28 V respectively, which indicated the magnesium electrode had the induction effect on the electrodeposition of lithium compared with molybdenum electrode. The current efficiency was calculated, and the values were all larger than 92%. The morphology of the magnesium electrode and the magnesium electrode with lithium deposited were studied by scanning electronic microscopy. The results showed that on the magnesium electrode a compact and homogeneous alloy layer was form by lithium electrodeposition. The main impure element was oxygen, as observed by EDX, which probobly was introduced after the alloy was prepared.