The electrochemical proporties of co-sputtered Cu5Si thin film anodes

• Main Authors: Wan-Tien Chou, 周宛瑱
• Other Authors: 林新智
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/25043048074238024234

碩士 === 臺灣大學 === 材料科學與工程學研究所 === 96 === In the portable electronics industry, the recent trend has been toward smaller and more powerful devices. This requires batteries made from materials with very high energy densities. However, to meet the ever-increasing energy demands of modern devices, researchers are seeking new materials that will lead to smaller, lighter, and longer-lasting batteries. Cu5Si/Si thin-film anodes have been prepared using radio frequency driven magnetron sputtering. With appropriate working pressure during deposition, film residual stress and surface morphology can be well controlled. Field-emission scanning electron microscopy and bending beam apparatus were used to characterize the surface morphology and residual stress, respectively. Cu5Si/Si thin-film anodes deposited with low working pressure can develop smooth surface morphology and large compressive stress. The electrochemical properties of the thin-film anodes deposited under various conditions were measured and compared. The Cu5Si/Si thin-films deposited at a working pressure of 1 mTorr demonstrated that the first charge and discharge capacities of the materials were about 2518 mAh/g and 2343 mAh/g, respectively, with 93% of the first cycle efficiency. The cycle life performance of this material showed that the initial discharge capacity of 2343 mAh/g could be maintained up to 86% after 50 cycles. The cycling performance of the Cu5Si/Si thin-film anodes were improved significantly.