School of Chemical Engineering, Sichuan University, Chengdu, 610065, P. R. China.
Institute of Materials Science and Devices, Suzhou University of Science and Technology, Suzhou, 215011, China.
Angew Chem Int Ed Engl. 2023 Mar 13;62(12):e202300209. doi: 10.1002/anie.202300209. Epub 2023 Feb 14.
Interface fusion plays a key role in constructing Ni-based single-crystal cathodes, and is governed by the atomic migration related to kinetics. However, the interfacial atom migration path and its control factors are lack of clearly understanding. Herein, we systematically probe the solid-state synthesis mechanism of single-crystal LiNi Co Mn O , including the effects of precursor size, Li/transition metal (TM) ratio and sintering temperature on the structure. Multi-dimensional analysis unravels that thermodynamics drives interface atoms migration through intermediate state (i.e., cation mixing phase) to induce grain boundary fusion. Moreover, we demonstrate that smaller precursor size (<6 μm), lager Li/TM ratio (>1.0) and higher temperature (≥810 °C) are conducive to promote the growth of the intermediate state due to reaction kinetics enhancement, and ultimately strengthen the atomic migration-induced interface fusion.
界面融合在构建镍基单晶阴极中起着关键作用，受动力学相关的原子迁移控制。然而，界面原子迁移路径及其控制因素尚不清楚。在此，我们系统地研究了单晶 LiNi Co Mn O 的固态合成机制，包括前体尺寸、Li/TM 比和烧结温度对结构的影响。多维分析表明，热力学通过中间相（即阳离子混合相）驱动界面原子迁移，从而引发晶界融合。此外，我们证明了较小的前驱体尺寸（<6μm）、较大的 Li/TM 比（>1.0）和较高的温度（≥810℃）由于反应动力学增强，有利于促进中间相的生长，从而最终增强原子迁移诱导的界面融合。
