Si–Y multi-layer thin films as anode materials of high-capacity lithium-ion batteries

• Published in: Journal of power sources Vol. 217; pp. 102 - 107
• Main Authors: Li, Haixia, Bai, Hongmei, Tao, Zhanliang, Chen, Jun
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.11.2012; Elsevier
• Subjects: Anode material; Anodes; Applied sciences; Current density; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Exact sciences and technology; Lithium batteries; Lithium-ion batteries; Lithium-ion battery; Magnetron sputtering; Materials; Multi-layer thin films; Multilayers; Scanning electron microscopy; Silicon; Thin films; Anode material; Lithium-ion battery; Multi-layer thin films; Magnetron sputtering; Performance evaluation; Anode; Alkaline storage battery; Electrode material; Electrochemical characteristic; Thin film; Charge measurement; Cyclic voltammetry; Current density; Scanning electron microscopy; Multilayer coating; Secondary cell; Layer thickness; Reversible capacity; Lithium battery; Transmission electron microscopy; Energy dispersion; Morphology; Cathodic sputtering; Comparative study; Electrochemical impedance spectroscopy
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2012.05.080

In this paper, we report on the preparation of Si–Y multi-layer thin films by magnetron sputtering and their application as anode materials of lithium-ion batteries. Scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) and transmission electron microscopy (TEM) have been used to characterize the morphologies and structures of the as-prepared thin films. The framework of the Si–Y thin films is Y-Si-Y-Si multi-layers, including the Si thin film with a thickness of 225nm and the Y thin film with different thickness (15–37.5nm). The electrochemical performance of the samples is investigated by charge–discharge measurement, cyclic voltammetry and electrochemical impedance spectra (EIS). Compared with pure Si thin film, the Si–Y thin films with the optimal Y film thickness of about 22.5nm can deliver a high reversible capacity of 2450mAhg−1 under a current density of 0.4C after 50 cycles, showing superior cycle performance and electrode stability due to the better Li+ diffusion character. This study should shed light on the design and application of Si–Y multi-layer thin films as anode materials of high-capacity lithium-ion batteries. ► Si–Y multi-layer thin films have been prepared by radio frequency magnetron sputtering. ► The sample with the Y thin film of 22.5 nm shows excellent cycle performance. ► The Y thin film can act as a buffer layer to improve the Li-ion kinetic property.