Liu Zhengliang, Bi Zhuanfang, Shang Yang, Liang Yaowen, Yang Peifa, Li Xiao, Zhang Chuandi, Shang Guangyi
School of Physics, Beihang University, Beijing 100191, People's Republic of China.
Pillar of Engineering Product Development, Singapore University of Technology and Design, 8 Somapah Road, 487372, Singapore.
Rev Sci Instrum. 2020 Oct 1;91(10):103701. doi: 10.1063/5.0024425.
Development of lithium ion batteries with ultrafast charging rate as well as high energy/power densities and long cycle-life is one of the imperative works in the field of batteries. To achieve this goal, it requires not only to develop new electrode materials but also to develop nano-characterization techniques that are capable of investigating the dynamic evolution of the surface/interface morphology and property of fast charging electrode materials during battery operation. Although electrochemical atomic force microscopy (EC-AFM) holds high spatial resolution, its imaging speed is too slow to visualize dynamics occurring on the timescale of minutes. In this article, we present an electrochemical high-speed AFM (EC-HS-AFM), developed by addressing key technologies involving optical detection of small cantilever deflection, dual scanner capable of high-speed and wide-range imaging, and electrochemical cell with three electrodes. EC-HS-AFM imaging from 1 fpm to ∼1 fps with a maximum scan range of 40 × 40 µm has been stably and reliably realized. Dynamic morphological changes in the LiMnO nanoparticles during cyclic voltammetry measurements in the 0.5 mol/l LiSO solution were successfully visualized. This technique will provide the possibility of tracking dynamic processes of fast charging battery materials and other surface/interface processes such as the formation of the solid electrolyte interphase layer.
开发具有超快充电速率、高能量/功率密度和长循环寿命的锂离子电池是电池领域的重要工作之一。为实现这一目标，不仅需要开发新的电极材料，还需要开发能够研究快速充电电极材料在电池运行过程中表面/界面形态和性能动态演变的纳米表征技术。尽管电化学原子力显微镜（EC-AFM）具有高空间分辨率，但其成像速度太慢，无法可视化在几分钟时间尺度上发生的动态过程。在本文中，我们展示了一种电化学高速原子力显微镜（EC-HS-AFM），它通过解决涉及小悬臂梁偏转的光学检测、能够进行高速和宽范围成像的双扫描器以及三电极电化学池等关键技术而开发。已经稳定可靠地实现了从1 fpm到约1 fps的EC-HS-AFM成像，最大扫描范围为40×40 µm。成功可视化了LiMnO纳米颗粒在0.5 mol/l LiSO溶液中循环伏安测量期间的动态形态变化。该技术将为跟踪快速充电电池材料的动态过程以及其他表面/界面过程（如固体电解质中间相层的形成）提供可能性。
