Facile Synthesis of Core-Shell Structured SiO₂@Carbon Composite Nanorods for High-Performance Lithium-Ion Batteries

• Main Authors: Haibo Pang, Weicai Zhang, Peifeng Yu, Ning Pan, Hang Hu, Mingtao Zheng, Yong Xiao, Yingliang Liu, Yeru Liang
• Format: Article
• Language: English
• Published: MDPI AG 2020-03-01
• Series: Nanomaterials
• Subjects: sio₂; core-shell structures; composite; lithium-ion battery
• Online Access: https://www.mdpi.com/2079-4991/10/3/513

Recently, SiO₂ has attracted wide attention in lithium-ion batteries owing to its high theoretical capacity and low cost. However, the utilization of SiO₂ is impeded by the enormous volume expansion and low electric conductivity. Although constructing SiO₂/carbon composite can significantly enhance the electrochemical performance, the skillful preparation of the well-defined SiO₂/carbon composite is still a remaining challenge. Here, a facile strategy of in situ coating of polydopamine is applied to synthesis of a series of core-shell structured SiO₂@carbon composite nanorods with different thicknesses of carbon shells. The carbon shell uniformly coated on the surface of SiO₂ nanorods significantly suppresses the volume expansion to some extent, as well as improves the electric conductivity of SiO₂. Therefore, the composite nanorods exhibit a remarkable electrochemical performance as the electrode materials of lithium-ion batteries. For instance, a high and stable reversible capacity at a current density of 100 mA g^−1 reaches 690 mAh g^−1 and a capacity of 344.9 mAh g^−1 can be achieved even at the high current density of 1000 mA g^−1. In addition, excellent capacity retention reaches 95% over 100 cycles. These SiO₂@carbon composite nanorods with decent electrochemical performances hold great potential for applications in lithium-ion batteries.