Zhao Mingyuan, Yang Shaobin, Dong Wei
College of Mines, Liaoning Technical University, Fuxin, China.
College of Materials Science & Engineering, Liaoning Technical University, Fuxin, China.
Front Chem. 2022 Jun 27;10:932650. doi: 10.3389/fchem.2022.932650. eCollection 2022.
Nanostructure silicon is one of the most promising anode materials for the next-generation lithium-ion battery, but the 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 a low-temperature aluminum reduction process. The low temperature of 260°C 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°C 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 batteries, SNF yield a high reversible capacity of 2005.4 mAh g at 0.5 A g after 50 cycles and 1017.6 mAh g at 2 A g after 200 cycles, remarkably outperforming commercial Si material. With a low-cost precursor and facile approach, this work provides a new strategy for the synthesis of a commercial high-capacity Si anode.
纳米结构硅是下一代锂离子电池最有前景的负极材料之一，但复杂的合成工艺和高成本限制了其大规模商业应用。在此，提出了一种简单且低成本的方法，以天然海泡石为模板，通过低温铝热还原法制备硅纳米纤维（SNF）。还原过程中260°C的低温不仅降低了生产成本，还避免了传统镁热还原过程中600°C以上高温对天然海泡石结构的破坏，使得最终产物具有更完整的纳米纤维结构。首次通过实验验证了Mg-O八面体结构在低温铝热还原过程中对维持纳米纤维结构的重要作用。当用作锂离子电池负极时，SNF在0.5 A g下50次循环后可逆容量高达2005.4 mAh g，在2 A g下200次循环后为1017.6 mAh g，明显优于商业硅材料。这项工作以低成本前驱体和简便方法为商业高容量硅负极的合成提供了新策略。
