Enhancement of Cycle Performance of Si/TiFeSi2 Nanocomposite As Lithium Storage Material By Mechanical Deformation

Wednesday, 4 October 2017
Prince George's Exhibit Hall D/E (Gaylord National Resort and Convention Center)
H. I. Park, M. Sohn (Hanyang University), J. H. Choi (Korea Electrotechnology Research Institute), C. Park (Iljin electric Co. Ltd.), J. H. Kim (Kookmin University), and H. Kim (Hanyang University)
Although silicon has higher reversible capacity than graphite as a lithium storage material, its large volume change during lithium insertion and extraction causes poor capacity retention. To address this technical issue, melt-spun Si based alloy materials have been suggested as promising materials for lithium ion batteries because of their high capacity and relatively low production cost. However, their long-term cycle performance should be further improved for the commercial success. In this study, it is demonstrated that mechanical deformation can improve the electrochemical performances of melt-spun Si alloy material. By applying the high-energy mechanical milling to melt-spun Si/TiFeSi2, Si/TiFeSi2 nanocomposite is successfully modified with a size of few nanometer, and that is clearly observed by X-ray diffraction (XRD) and transmission electron microscope (TEM). As s result, the microstructurally tuned Si/TiFeSi2 showed a reversible capacity of more than 1000 mAh g-1 with stable capacity retention up to 100 cycles. More detailed studies on the reasons for better cycle performance of milled Si/TiFeSi2 will be discussed in this presentation.