Jiao Handong, Qu Zhaoliang, Jiao Shuqiang, Gao Yang, Li Shijie, Song Wei-Li, Wang Mingyong, Chen Haosen, Fang Daining
Institute of Advanced Structure Technology, Beijing Institute of Technology, Beijing, 100081, P. R. China.
State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing, 100083, P. R. China.
Adv Sci (Weinh). 2021 Dec;8(24):e2101373. doi: 10.1002/advs.202101373. Epub 2021 Oct 28.
Electrodeposition is a fundamental technology in modern society and has been widely used in metal plating and extraction, etc. However, extreme reaction conditions, including wide operation temperature ranges and corrosive media (molten salt/oxide systems as a particular example), inhibit direct in situ observation of the electrodeposition process. To visualize the electrode kinetics in such "black box," X-ray tomography is employed to monitor the electrochemical processes and three-dimensional (3D) evolution of morphology. Benefiting from the excellent penetration of X-ray, a non-destructive and non-contact in situ four-dimensional (4D) visualization of Ti deposition is realized. Real-time 3D reconstructed images reveal that the counterintuitive nucleation and growth process of a mesoscale Ti dendrite at both solid and liquid cathodes. According to 3D morphology evolution, unusual mechanism based on synergetic effect of the diffusion of metallic Ti and local field enhancement is achieved utilizing a simulation method based on a finite element method. This approach allows for timely and accurately regulating the electrodeposition process upon in situ monitored parameters. More importantly, the 4D technique upon operando X-ray tomography and numerical simulation can be easily applied to other electrodeposition systems, which will help deeply understand the internal kinetics and the precise optimization of the electrodeposition conditions.
电沉积是现代社会中的一项基础技术，已广泛应用于金属电镀和提取等领域。然而，极端的反应条件，包括较宽的操作温度范围和腐蚀性介质（以熔盐/氧化物体系为例），阻碍了对电沉积过程的直接原位观察。为了可视化这种“黑箱”中的电极动力学，采用X射线断层扫描来监测电化学过程和形态的三维（3D）演变。受益于X射线的出色穿透能力，实现了对钛沉积的非破坏性、非接触式原位四维（4D）可视化。实时3D重建图像揭示了中尺度钛枝晶在固态和液态阴极上违反直觉的成核和生长过程。根据3D形态演变，利用基于有限元方法的模拟方法，实现了基于金属钛扩散和局部场增强协同效应的异常机制。这种方法能够根据原位监测参数及时、准确地调节电沉积过程。更重要的是，基于操作X射线断层扫描和数值模拟的4D技术可以轻松应用于其他电沉积系统，这将有助于深入理解内部动力学并精确优化电沉积条件。
