GOALI: A Comparative Study of Electrochemical Codeposition with In-Situ Electron Microscopy

该提案打算使用各种工具，与IBM的支持和合作，研究真实的时间电化学共沉积的纳米力学。 对于锌-铋和铋-碲共沉积系统，将应用恒电位、恒电流和脉冲控制，同时以良好的时间分辨率（每秒30个图像）和空间分辨率（优于20 nm）对沉积结构的发展形态进行成像-原位，在液体电解质内。这将提供关于电化学加工期间纳米级存款形态演变的独特信息。 这项研究解决了一个显着的差距，目前的理解共沉积过程：形态和化学计量如何根据不同的过程控制制度和电解质constituences.The两个模型共沉积系统概述了在这个建议中有希望用于能源相关的技术。在电化学存储结构中，锌阳极长期以来一直具有吸引力，原因在于：1）当与空气或低成本阴极配对时的高能量密度，2）丰度，以及3）成本。迄今为止，二次锌阳极由于倾向于树枝状结构而难以实现。已知铋抑制工作锌电池中的析氢，并且添加铋以增加保质期，因此铋是镀锌结构感兴趣的添加剂。对于另一个应用，碲化铋的轻微非化学计量是热电装置（冷却装置和发电机两者）的主力结构。热电的功效由互补p型和n型结构的相对化学性质决定。 在实验室之外，拟议的研究将为高中和本科生提供原位显微镜和种子讲座，演示和在线媒体的核心主题。

This proposal intends to use a variety of tools, with support and collaboration from IBM, to study the nanoscale mechanics of electrochemical codeposition in real time. For the zinc-bismuth and bismuth-tellurium codeposition systems potentiostatic, galvanostatic, and pulsed control will be applied while simultaneously imaging the developing morphology of the deposited structure - in situ, within the liquid electrolyte - with good temporal resolution (30 images per second) and spatial resolution (better than 20nm). This will provide unique metrological information on the evolution of the deposit morphology at the nanoscale during electrochemical processing. This study addresses a significant gap in current understanding of codeposition processes: how morphology and stoichiometry vary under different process control regimes and electrolyte compositions.The two model codeposition systems outlined in this proposal have promise for use in energy related technologies. In electrochemical storage structures zinc anodes have long been attractive for reasons of 1) high energy density when paired with air or low-cost cathodes, 2) abundance, and 3) cost. To date secondary zinc anodes have been difficult to achieve due to a tendency toward dendritic structures. Bismuth is known to suppress hydrogen evolution in a working zinc battery and is added to increase shelf life, thus is an additive of interest to plated zinc structure. For another application, slight non-stoichiometries of bismuth telluride are the workhorse structures for thermoelectric devices, both cooling devices and electrical generators. The efficacy of the thermoelectric is determined by the relative chemistries of the complementary p and n type structures. Outside the laboratory the proposed research will serve a core topic of in-situ microscopy and seed lectures, demonstrations and online media for high school and undergraduate students.