Open AccessTemplate‐Free Electrochemical Formation of Silicon Nanotubes from Silica
Author(s) -
Weng Wei,
Yang Jiarong,
Zhou Jing,
Gu Dong,
Xiao Wei
Publication year - 2020
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.202001492
Subject(s) - materials science , silicon , microstructure , electrolysis , chemical engineering , electrochemistry , electrolyte , nanotechnology , lithium (medication) , electrode , metallurgy , chemistry , medicine , engineering , endocrinology
Silicon, with its elaborate microstructure, plays important roles in energy materials. In operando engineering of microstructure during extraction is an ideal protocol to develop advanced Si‐based materials. A template‐free electrochemical preparation of silicon nanotubes (Si‐NT) is herein achieved by co‐electrolysis of SiO 2 and AgCl in molten NaCl–CaCl 2 at 850 °C. The in situ electrodeposited Ag facilitates the generation of a liquid Ag–Si intermediate, triggering a liquid–solid mechanism to direct the growth of Si‐NT. An automatic separation of Ag from Si then occurs in the following cooling process, resulting in Ag deposits on the Ni current collector and recycling of Ag. Such a facile and smart preparation of Si‐NT from affordable silica guarantees an enhanced current efficiency of 74%, a decreased energy consumption of 12.1 kW h kg Si −1 , and enhanced lithium‐storage capability of the electrolytic Si‐NT. An in situ coating of Ag over the Si‐NT can also be fulfilled by simply introducing soluble AgCl in the melts. The present study provides a template‐free preparation and an in situ surface modification of Si‐NT.