锂离子电池Sn-Al薄膜电极的制备及电化学性能研究

采用磁控溅射沉积技术制备了纳米级Sn-Al合金薄膜电极材料,并用X射线衍射和扫描电子显微镜进行表征,用高精度电池测试系统进行充放电和循环伏安测试.结果表明直流DC与射频RF两种不同的溅射方法制备的Sn-Al薄膜电极具有很大的性能差异,前者DC法制备的材料颗粒细小,表现出稳定的循环性能,其首次放电容量为1060 mAh/g,首次效率为71.7％,电极经过50次循环后比容量保持在700 mAh/g以上.后者RF法制备的材料颗粒较大,放电比容量开始上升,第五次循环后接着逐渐衰减,表现出较差的循环性能. 关键词： 锂离子电池 磁控溅射 Sn-Al合金 电化学性能

preparation and properties of Sn-Al thin-film electrode material for lithium ion batteries

Nano-level Sn-Al alloy thin-film electrode materials prepared by magnetic sputtering technology are characterized with X-ray diffraction (XRD) and scanning electron microscopy (SEM). The charge/discharge and the cyclic voltammograms of the film electrodes are tested by the high precision battery testing system. The results indicate that the materials prepared by direct current and radiofrequency methods have a large difference in performance. The films prepared by DC method have small particles and excellent cycling stability. Its initial discharge capacity and efficiency are 1060 mAh/g and 71.7%, respectively, and the specific capacitance is over 700 mAh/g after 30 cycles. But the films prepared by RF method have the bigger particles and inferior cycle performance, and its specific capacitance initially increases but after 5 times cycle it declines.