Kang Sujin, Yeom Su Jeong, Lee Hyun-Wook
School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulju-gun, Ulsan, 44919, Republic of Korea.
ChemSusChem. 2020 Mar 20;13(6):1480-1484. doi: 10.1002/cssc.201903289. Epub 2020 Mar 5.
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 by using planar observations. This study concerns 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, this technique can be used to study the corresponding charge-discharge kinetics. In addition, the cell configuration uses liquid electrolytes similar to commercial cells, allowing practical application. Furthermore, this side-view observation has shown that microscale spatial variations in rate and composition control the insertion and deinsertion, revealing the kinetics throughout the whole electrode. The results of this study could enhance the fundamental understanding of the kinetics of battery materials.
原位分析在高性能材料和器件（包括储能系统）的构建方面取得了多项突破。然而，尽管电极工程取得了进展，但锂嵌入和脱嵌动力学的棘手问题无法通过平面观测来研究。本研究涉及通过光学显微镜对石墨阳极进行侧视原位观测，基于其在电化学锂化过程中的颜色变化。由于石墨颜色在锂化和脱锂过程中会根据光学能隙而变化，该技术可用于研究相应的充放电动力学。此外，电池配置使用了类似于商业电池的液体电解质，具有实际应用价值。此外，这种侧视观测表明，速率和组成的微观尺度空间变化控制着嵌入和脱嵌过程，揭示了整个电极的动力学。本研究结果可增进对电池材料动力学的基本理解。
