| 초록 |
In search of new non-carbonaceous materials for lithium ion batteries, silicon has been tested as a possible candidate. In order to examine the intrinsic properties of this metal versus a lithium electrode a 293K. Silicon thin films have been deposited by rf magnetron sputtering system and characterized. Capacities of 1700mAh/g have been measured in films with thickness ranging from 1 to 3㎛. These capacities are probably due to the formation of amorphous Li-Si alloys as indicated by X-ray diffraction analysis and electrochemical measurements. The huge stress induced by volume changes upon cycling have been evidenced by scanning electron microscopy observations. After a few cycles, silicon films lost their own capacity. As aluminium was doped, silicon films could endure the stress induced by volume changes during the cycles. Aluminium as a doping material helped silicon retain its capacity and overcome stress from the large volume change. Aluminium doped silicon appears as a good material as negative electrode for lithium ion batteries. |
