Evaluation of Si/Ge multi-layered negative film electrodes using magnetron sputtering for rechargeable lithium ion batteries

• Published in: Thin solid films 2011-01, Vol.519 (7), p.2332-2338
• Main Authors: Hwang, Chang-Mook, Lim, Chae-Ho, Park, Jong-Wan
• Format: Article
• Language: English
• Subjects: Anode; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cracks; Cross-disciplinary physics: materials science; rheology; Deposition; Deposition by sputtering; Diffusion; interface formation; Electrodes; Electron and ion emission by liquids and solids; impact phenomena; Exact sciences and technology; Field emission, ionization, evaporation, and desorption; Germanium; Lithium; Lithium ion batteries; Magnetron sputtering; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Multi-layer; Physics; Scanning electron microscopy; Silicon; Solid surfaces and solid-solid interfaces; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; X-rays
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2010.10.049

The capacity of a silicon anode diminishes during repeated lithium ion intercalation and extraction as the volume changes cause the active material to internally crack. In this study, electrodes are prepared by a deposition method, and silicon and germanium are deposited on the copper current collector in sequence. The number of layers is varied and we find evidence that a multi-layered structure is capable of improving cyclic ability. It is expected that germanium would act as a buffer against the volume change of the silicon and contribute to the elevating lithium ion diffusion. The morphologic changes and cyclic performances of the multi-layered electrodes prepared by the deposition method are observed. Deposited electrodes are verified by X-ray diffractometry, Raman spectroscopy, field-emission scanning electron microscopy and transmission electron microscopy. Si―Ge bonding at the interface is analyzed using extended X-ray absorption fine structure.