Operando Nanoindentation: A New Platform to Measure the Mechanical Properties of Electrodes during Electrochemical Reactions
Operando Nanoindentation: A New Platform to Measure the Mechanical Properties of Electrodes during Electrochemical Reactions
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DOI：
10.1149/2.1411714jes
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发表时间：
2017
影响因子：
3.9
通讯作者：
L. Vasconcelos;Rong Xu;K. Zhao
中科院分区：
文献类型：
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作者：
L. Vasconcelos;Rong Xu;K. Zhao
我们提出了一个实验平台的操作纳米压痕，探针的动态力学行为的电极在实时电化学反应。该装置包括一个纳米压头，电化学站，和一个定制的惰性环境中集成的微流体电池。我们评估的影响氩气气氛，电解质溶液，结构退化和体积变化的电极上Li反应，以及表面层和基板效应的控制实验。结果告知系统的局限性和能力，并提供最佳实验实践的指导方针。此外，我们提出了一个彻底的调查的非晶硅电极的弹粘塑性特性，在不同的C-率和开路的电池操作过程中。单独表征纯Li金属。我们测量了锂化硅的弹性模量、硬度和蠕变应力指数的连续演化，并将结果与以前的报道进行了比较。操作压痕将提供一个可靠的平台，以了解能源材料的力学和电化学之间的基本耦合。纳米压痕充放电纳米压痕是在经历电化学反应的硅电极上进行的。试验不间断地进行，压痕之间的网格间距为40 μ m。在标准保持器上对Li金属带进行单独的非原位测量（一个压痕深度为33个压痕）。
We present an experimental platform of operando nanoindentation that probes the dynamic mechanical behaviors of electrodes during real-time electrochemical reactions. The setup consists of a nanoindenter, an electrochemical station, and a custom fluid cell integrated into an inert environment. We evaluate the influence of the argon atmosphere, electrolyte solution, structural degradation and volumetric change of electrodes upon Li reactions, as well as the surface layer and substrate effects by control experiments. Results inform on the system limitations and capabilities, and provide guidelines on the best experimental practices. Furthermore, we present a thorough investigation of the elastic-viscoplastic properties of amorphous Si electrodes, during cell operation at different C-rates and at open circuit. Pure Li metal is characterized separately. We measure the continuous evolution of the elastic modulus, hardness, and creep stress exponent of lithiated Si and compare the results with prior reports. operando indentation will provide a reliable platform to understand the fundamental coupling between mechanics and electrochemistry in energy materials. nanoindentation charge- discharge.— Nanoindentation is performed on a silicon electrode undergoing electrochemical reactions. Tests are conducted uninterrupt- edly with a grid spacing of 40 μ m between indents. Separate, ex-situ measurements (33 indents for one indentation depth) are performed on Li metal ribbons on a standard holder.