AUTHOR=Zhao Mingyuan , Yang Shaobin , Dong Wei 

TITLE=Low Temperature Aluminothermic Reduction of Natural Sepiolite to High-Performance Si Nanofibers for Li-Ion Batteries

JOURNAL=Frontiers in Chemistry

VOLUME=Volume 10 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2022.932650

DOI=10.3389/fchem.2022.932650

ISSN=2296-2646

ABSTRACT=Nanostructure silicon is one of the most promising anode materials for the next generation lithium-ion battery, but complicated synthesis process and high cost limit its large-scale commercial application. Herein, a simple and low-cost method was proposed to prepare silicon nanofibers (SNF) using natural sepiolite as a template via a low temperature aluminum reduction process. The low temperature of 260 ℃ during the reduction process not only reduced the production cost, but also avoided the destruction of the natural sepiolite structure caused by the high temperature above 600 ℃ in the traditional magnesium thermal reduction process, leading to a more complete nanofiber structure in the final product. For the first time, the important role of Mg-O octahedral structure in the maintenance of nanofiber structure during the process of low temperature aluminothermic reduction was verified by experiments. When used as an anode for lithium-ion battery, SNF yield a high reversible capacity of 2005.4 mAh g-1 at 0.5 A g-1 after 50 cycles and 1197.6mAh g-1 at 2 A g-1 after 200 cycles, remarkably outperforming commercial Si material. With low-cost precursor and facile approach, this work provides a new strategy for the synthesis of commercial high-capacity Si anode.