英国剑桥大学Akshay Rao，Clare P. Grey和Christoph Schnedermann研究团队研制了电池中单粒子离子动力学的Operando光学跟踪。相关论文于2021年6月23日发表在《自然》杂志上。
在这里，研究人员介绍了一种简单的基于实验室的光学干涉散射显微镜来解决电池材料中的纳米锂离子动力学问题，并将其应用于跟踪电极基质中典型正极材料LixCoO2的单个粒子的循环。
该研究组直接可视化绝缘体到金属、固溶体和锂有序相变，并确定锂在单粒子水平的扩散率，识别不同的充放电机制。最后，研究小组捕获了Li0.5CoO2组分中与单斜晶格畸变相关的不同晶体取向间畴界的动态形成。
该方法的高通量特性允许在整个电极上取样许多粒子，未来将有助于探索位错、形态和循环速率对电池退化的作用。他们成像概念的通用性意味着它可以应用于任何电池电极的研究，更广泛的是，可以应用于离子传输与电子或结构变化相关的系统。这些系统包括纳米离子薄膜、离子导电聚合物、光催化材料和记忆电阻器。
据悉，推进锂离子电池技术的关键——尤其是快速充电——是能够实时地、在纳米到中观尺度上跟踪和理解功能材料在现实条件下发生的动态过程。目前，电池运行期间的锂离子动态成像(Operando成像)需要复杂的同步x射线或电子显微镜技术，这些技术并不适合高通量材料筛选。这限制了快速和理性的材料改进。
附：英文原文
Title: Operando optical tracking of single-particle ion dynamics in batteries
Author: Alice J. Merryweather, Christoph Schnedermann, Quentin Jacquet, Clare P. Grey, Akshay Rao
Issue&Volume: 2021-06-23
Abstract: The key to advancing lithium-ion battery technology—in particular, fast charging—is the ability to follow and understand the dynamic processes occurring in functioning materials under realistic conditions, in real time and on the nano- to mesoscale. Imaging of lithium-ion dynamics during battery operation (operando imaging) at present requires sophisticated synchrotron X-ray1,2,3,4,5,6,7 or electron microscopy8,9 techniques, which do not lend themselves to high-throughput material screening. This limits rapid and rational materials improvements. Here we introduce a simple laboratory-based, optical interferometric scattering microscope10,11,12,13 to resolve nanoscopic lithium-ion dynamics in battery materials, and apply it to follow cycling of individual particles of the archetypal cathode material14,15, LixCoO2, within an electrode matrix. We visualize the insulator-to-metal, solid solution and lithium ordering phase transitions directly and determine rates of lithium diffusion at the single-particle level, identifying different mechanisms on charge and discharge. Finally, we capture the dynamic formation of domain boundaries between different crystal orientations associated with the monoclinic lattice distortion at the Li0.5CoO2 composition16. The high-throughput nature of our methodology allows many particles to be sampled across the entire electrode and in future will enable exploration of the role of dislocations, morphologies and cycling rate on battery degradation. The generality of our imaging concept means that it can be applied to study any battery electrode, and more broadly, systems where the transport of ions is associated with electronic or structural changes. Such systems include nanoionic films, ionic conducting polymers, photocatalytic materials and memristors.
DOI: 10.1038/s41586-021-03584-2
Source: https://www.nature.com/articles/s41586-021-03584-2