Electrochemical preparation/processing of functional silicon from abundant silica is an ideal protocol to promote sustainability of energy sectors. Such an imperative task is challenged by poor electrical conductivity of Si/SiO₂ and inadequate mass diffusion of bulk silicon. Herein, a template-free and one-step preparation of silicon nanotubes (Si-NT) from electrochemical reduction of silica in molten salts is reported. An in situ oriented growth of silicate nanorods (NRs) from silica is clarified as the key step to direct a self-template evolution of Si-NT from silica. The silicate-mediated construction of Si-based NT is versatile and successfully extended to prepare Si-NT/graphite and Ti_xSi_y-NT. Benefitting from fast longitudinal motorways for fast transport of electrons and ions along/inside NTs, an energy consumption 30% lower than industrial silicon production is achieved. When evaluated as anode of lithium ion battery, the Si-NT-based electrodes show outstanding initial Coulombic efficiency and high reversible capacity. The silicate-mediated construction of Si-based NT integrates straightforward preparation and intriguing functionality of Si-based materials, bridging a closed-loop Si-based energy infrastructure.

中文翻译：

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来自熔融盐中二氧化硅的硅酸盐介导的电解硅纳米管

从丰富的二氧化硅中电化学制备/加工功能性硅是促进能源部门可持续发展的理想方案。_{这种紧迫的任务受到Si/SiO 2}导电性差和体硅质量扩散不足的挑战。本文报道了一种无模板的一步法制备硅纳米管 (Si-NT) 的方法，该方法是通过电化学还原熔融盐中的二氧化硅来制备。从二氧化硅中原位定向生长硅酸盐纳米棒 (NRs) 被阐明为指导从二氧化硅中自模板演化 Si-NT 的关键步骤。硅基 NT 的硅酸盐介导结构用途广泛，并成功扩展到制备 Si-NT/石墨和 Ti _x Si _y-NT。受益于快速纵向高速公路沿/在 NT 内快速传输电子和离子，实现了比工业硅生产低 30% 的能耗。当作为锂离子电池的负极进行评估时，Si-NT 基电极表现出出色的初始库仑效率和高可逆容量。硅基 NT 的硅酸盐介导结构集成了硅基材料的简单制备和有趣的功能，桥接了一个闭环的硅基能源基础设施。