Zuo Wenhua, Gim Jihyeon, Li Tianyi, Hou Dewen, Gao Yibo, Zhou Shiyuan, Zhao Chen, Jia Xin, Yang Zhenzhen, Liu Yuzi, Xu Wenqian, Xiao Xianghui, Xu Gui-Liang, Amine Khalil
Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL, USA.
X-ray Sciences Division, Advanced Photon Source, Argonne National Laboratory, Lemont, IL, USA.
Nat Nanotechnol. 2024 Nov;19(11):1644-1653. doi: 10.1038/s41565-024-01734-x. Epub 2024 Aug 20.
Microstrain and the associated surface-to-bulk propagation of structural defects are known to be major roadblocks to developing high-energy and long-life batteries. However, the origin and effects of microstrain during the synthesis of battery materials remain largely unknown. Here we perform microstrain screening during real-time and realistic synthesis of sodium layered oxide cathodes. Evidence gathered from multiscale in situ synchrotron X-ray diffraction and microscopy characterization collectively reveals that the spatial distribution of transition metals within individual precursor particles strongly governs the nanoscale phase transformation, local charge heterogeneity and accumulation of microstrain during synthesis. This unexpected dominance of transition metals results in a counterintuitive outward propagation of defect nucleation and growth. These insights direct a more rational synthesis route to reduce the microstrain and crystallographic defects within the bulk lattice, leading to significantly improved structural stability. The present work on microstrain screening represents a critical step towards synthesis-by-design of defect-less battery materials.
微应变以及与之相关的结构缺陷从表面到整体的传播，是开发高能量、长寿命电池的主要障碍。然而，电池材料合成过程中微应变的起源和影响在很大程度上仍不为人知。在此，我们在钠层状氧化物阴极的实时、实际合成过程中进行了微应变筛选。从多尺度原位同步加速器X射线衍射和显微镜表征收集的证据共同表明，单个前驱体颗粒内过渡金属的空间分布强烈地控制着合成过程中的纳米级相变、局部电荷不均匀性和微应变的积累。过渡金属这种出乎意料的主导作用导致了缺陷成核和生长的反直觉向外传播。这些见解指引了一条更合理的合成路线，以减少体晶格内的微应变和晶体缺陷，从而显著提高结构稳定性。目前关于微应变筛选的工作是朝着无缺陷电池材料的设计合成迈出的关键一步。
