Operando analyses have provided several breakthroughs in the construction of high-performance materials and devices, including energy storage systems. However, despite the advances in electrode engineering, the formidable issues of lithium intercalation and deintercalation kinetics cannot be investigated via planar observations. Thus, we propose the side-view operando observation by optical microscopy of a graphite anode based on its color changes during electrochemical lithiation. Since the graphite color varies according to the optical energy gap during lithiation and delithiation, we could study the corresponding charge/discharge kinetics; in addition, our cell configuration uses liquid electrolytes similarly to commercial cells, allowing practical applications. Furthermore, this side-view observation has showed that microscale spatial variations in rate and composition control the insertion and desertion, revealing the kinetics through the whole electrode. The results of this study could enhance the fundamental understanding of the kinetics of battery materials.

中文翻译：

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石墨阳极的侧视图Operando光学显微镜分析，以研究其动力学滞后现象。

Operando分析为高性能材料和设备（包括储能系统）的构造提供了若干突破。然而，尽管电极工程技术取得了进步，但无法通过平面观测研究锂嵌入和脱嵌动力学的巨大问题。因此，我们提出了基于光学阳极在电化学锂化过程中通过其颜色变化通过光学显微镜对石墨阳极进行侧视图操作观察。由于石墨的颜色根据锂化和脱锂过程中的光能隙而变化，因此我们可以研究相应的充/放电动力学。此外，我们的电池配置与商用电池类似，使用液体电解质，可用于实际应用。此外，该侧面观察结果表明，速率和成分的微观空间变化控制着插入和离开，揭示了整个电极的动力学。这项研究的结果可以增强对电池材料动力学的基本了解。