EAGER: Understanding Electrochemical Alloying Reaction of Nanostructured Silicon with Magnesium: Impact of Nanoscale Silicon Processing

我们国家繁荣所需的新形式的能源储存需要开发新材料和新工艺。EARLY概念探索性研究资助（EAGER）将支持基础研究，这将有助于对纳米结构硅加工的新见解，纳米结构硅可作为镁离子电池的高性能阳极材料。镁离子电池已被建议作为更传统的锂离子电池的安全且廉价的替代品。 本研究旨在克服限制镁在纳米结构硅中存储的根本障碍，并研究新工艺路线与材料性能之间的关系。常规处理的纳米结构硅的表面覆盖有原生氧化硅，这限制了镁在硅中的储存。这里研究的新工艺路线有望产生无氧化物的纳米结构硅，使可逆地存储镁成为可能。将确定合成的纳米结构硅的尺寸、合成参数和存储性能之间的关系。这项研究的结果将为硅-地壳中第二丰富的元素-在镁电池中的使用开辟道路，这将有利于美国经济和社会。特别是，它将减轻目前用于可充电电池的锂和钴材料短缺的担忧。纳米结构硅与镁的可逆电化学合金化反应仍然是一个挑战。在这个项目中，假设无氧化物纳米结构硅的加工是硅与镁成功合金化反应的关键。为了验证这一假设，将研究一种新的原位无氧化物纳米结构硅的加工路线。当电池充电和放电时，该过程在镁离子电池单元中原位产生纳米结构材料。硅与镁的可逆合金化反应将在同一镁离子电池中直接研究整个充电和放电循环。这种处理方法可以避免纳米结构硅暴露在空气中，从而避免形成阻碍硅和镁之间反应的不希望的天然氧化硅表面膜。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

New forms of energy storage needed for our national prosperity requires the development of new materials and processes. This EArly-concept Grant for Exploratory Research (EAGER) will support fundamental research that will contribute to new insight on processing nanostructured silicon, which may serve as a high performance anode material for magnesium-ion batteries. Magnesium ion batteries have been suggested as a safe and inexpensive alternative to the more conventional lithium ion batteries. This research looks to overcome the fundamental barrier that restricts the storage of magnesium in nanostructured silicon, and study the relationship between the new processing route and the material performance. The surface of conventionally processed nanostructured silicon is covered with native silicon oxide, which restricts the storage of magnesium in silicon. The new processing route investigated here promises to lead to oxide-free nanostructured silicon, making it possible to reversibly store magnesium. The relationship between the size of the synthesized nanostructured silicon, the synthesis parameter, and the storage performance will be determined. Results from this research will open the way to the use of silicon -- the second most abundant element in the earth's crust, in a magnesium battery, which will benefit the US economy and society. In particular, it will lessen the concern of the material shortage in lithium and cobalt, which are currently used in rechargeable batteries.Reversible electrochemical alloying reaction of nanostructured silicon with magnesium remains a challenge. In this project, it is hypothesized that processing of oxide-free nanostructured silicon is the key to successful alloying reaction of silicon with magnesium. To verify this hypothesis, a new in situ processing route to oxide-free nanostructured silicon will be investigated. This process creates the nanostructured material in situ in a magnesium-ion battery cell when the battery is being charged and discharged. The reversible alloying reactions of silicon with magnesium will be directly investigated in the same magnesium-ion battery cell throughout charging and discharging cycles. This processing approach makes it possible to avoid any exposure of the nanostructured silicon to air, thus avoiding the formation of undesirable native silicon oxide surface films that hamper the reaction between silicon and magnesium.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.