标题: Electrochemical Conversion of Silica Nanoparticles to Silicon Nanotubes in Molten Salts: Implications for High-Performance Lithium-Ion Battery Anode
作者: Wang, F (Wang, Fan); Ma, YS (Ma, Yongsong); Li, P (Li, Peng); Peng, C (Peng, Chuang); Yin, HY (Yin, Huayi); Li, W (Li, Wei); Wang, DH (Wang, Dihua)
来源出版物: ACS APPLIED NANO MATERIALS 卷: 4 期: 7 页: 7028-7036 DOI: 10.1021/acsanm.1c01061 出版年: JUL 23 2021
摘要: Understanding the material formation mechanism is critical to guide the material synthesis and exploitation. Herein, we reveal a different conversion mechanism of SiO2 particles to Si nanotubes (SNTs) in the molten salt electrolysis. Unlike conventional strategies employing templates and/or catalysts, the one-step electrochemical synthesis is template- and catalyst-free, which process involves lamination, exfoliation, and reduction. Specifically, SiO2 particles are first converted into layer-structured CaSiO3, from which CaO and O2- are subsequently extracted, causing the collapse of the layer structure and forming SiOx (0 < x < 2) layers. The newly formed SiOx layers are finally deeply reduced into SNTs. Besides, the morphology of silicon-based nanostructures can be controlled via altering the applied voltage between a SiO2 cathode and a graphite anode. In addition, the electrolytic SNTs show enhanced lithium-storage performances, such as a high specific capacity (2485 mAh g(-1) at 0.2 A g(-1)) and an excellent rate capability (1362 mAh g(-1) at 5 A g(-1)), which is benefited from the tube structure that can buffer the volume variation of Si. Overall, the revealed conversion mechanism will shed light on designing advanced Si-based nanomaterials for various applications.
作者关键词: deoxidation; silicon nanotubes; molten salt electrolysis; SiO2; lithium-ion batteries
地址: [Wang, Fan; Ma, Yongsong; Li, Peng; Peng, Chuang; Li, Wei; Wang, Dihua] Wuhan Univ, Sch Resource & Environm Sci, Hubei Int Sci & Technol Cooperat Base Sustainable, Wuhan 430072, Peoples R China.
[Yin, Huayi] Northeastern Univ, Key Lab Ecol Met Multimet Mineral, Minist Educ, Sch Met, Shenyang 110819, Peoples R China.
通讯作者地址: Li, W; Wang, DH (通讯作者)，Wuhan Univ, Sch Resource & Environm Sci, Hubei Int Sci & Technol Cooperat Base Sustainable, Wuhan 430072, Peoples R China.
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