Insights into the conversion behavior of SiO-C hybrid with pre-treated graphite as anodes for Li-ion batteries. (1st January 2016)

• Record Type: Journal Article
• Authors: Wu, Wenjun; Liang, Yunhui; Ma, Haiyan; Peng, Yi; Yang, Huabin
• Is Part Of: Electrochimica acta. Volume 187(2016)
• Page Start: 473
• Page End: 479
• Publication Date: 2016-01-01
• Subjects: SiO-C composite -- Conversion behavior -- Electrochemical performance -- Anode material -- Lithium-ion batteries; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2015.11.008
• Languages: English
• ISSNs: 0013-4686

Abstract

Graphical abstract: Highlights: SiO-C composite is prepared by a low-cost and simple method. Pre-milling of graphite makes the components disperse more evenly. Pre-milling of graphite enhances the conductivity of the SiO-C composite. Cycling performance is improved by pre-milling of graphite. Li4 SiO4 and amorphous Si as the products of the 1st cycle are verified by HRTEM. Abstract: A SiO/graphite/amorphous carbon (SiO-C) hybrid anode with superior electrochemical performance is successfully realized by using a low-cost and simple method. Here, we apply a pretreatment of commercialized graphite by ball-milling to realize evenly dispersion of the components and good effect of carbon coating, thus resulting in excellent cycling stability. Specifically, the as-prepared sample shows a high reversible capacity of 850 mA h g −1 after 100 cycles at 100 mA g −1 and excellent rate capability of 730 mA h g −1 even at 500 mA h g −1 . Additionally, a relatively high initial coulombic efficiency of 77% is delivered among SiO-based anode materials. High-resolution transmission electron microscope (HRTEM) technique is used to further visually verify the conversion behavior of SiO in the first cycle: scattered amorphous silicon particles with size about 5 nm and irreversible Li4 SiO4 as the detected resultants. The result of electrochemical impedance spectroscopy (EIS) reveals that the polarization resistance (Rp) decreases with pre-treated graphite. This work presents a facile approach to prepare Si-based anode material for new generation lithium-ion batteries with high energy density and more insights into the conversion behavior of SiO.