Visualization of anisotropic-isotropic phase transformation dynamics in battery electrode particles.
Visualization of anisotropic-isotropic phase transformation dynamics in battery electrode particles.
复制标题
DOI：
10.1038/ncomms12372
复制
发表时间：
2016-08-12
影响因子：
16.6
通讯作者：
Wang J
中科院分区：
文献类型：
--
作者：
Wang J;Karen Chen-Wiegart YC;Eng C;Shen Q;Wang J
相变的各向异性或各向同性广泛存在于许多固态材料中，其性能取决于三维相变特征。对内部化学相演化的基本见解允许操纵具有所需功能的材料，并且可以通过实时多维成像方法进行开发。在这里，我们报告了一种五维成像方法，用于跟踪脱锂过程中单个磷酸铁锂电池阴极颗粒中作为充电时间函数的相变。电化学驱动的相变最初是各向异性的，具有优选的边界迁移方向，但随着脱锂的进一步进行而变得各向同性。我们还观察到整个充电过程中预期的两相共存。我们期望这种五维成像方法能够广泛应用于能源、材料、环境和生命科学领域的问题。 转变过程中的时空相演化会影响许多系统中的材料性能。在这里，作者使用定制设计的电池内的磷酸铁锂颗粒，通过 X 射线断层扫描在三维空间中表征不同充电状态下的两相配置。
Anisotropy, or alternatively, isotropy of phase transformations extensively exist in a number of solid-state materials, with performance depending on the three-dimensional transformation features. Fundamental insights into internal chemical phase evolution allow manipulating materials with desired functionalities, and can be developed via real-time multi-dimensional imaging methods. Here, we report a five-dimensional imaging method to track phase transformation as a function of charging time in individual lithium iron phosphate battery cathode particles during delithiation. The electrochemically driven phase transformation is initially anisotropic with a preferred boundary migration direction, but becomes isotropic as delithiation proceeds further. We also observe the expected two-phase coexistence throughout the entire charging process. We expect this five-dimensional imaging method to be broadly applicable to problems in energy, materials, environmental and life sciences. Spatiotemporal phase evolution during transformations impacts materials performance in many systems. Here the authors use lithium iron phosphate particles inside a custom-designed battery to characterize in three dimensions the two-phase configuration at various states of charge via X-ray tomography.