Sun Yifei, Hy Sunny, Hua Nelson, Wingert James, Harder Ross, Meng Ying Shirley, Shpyrko Oleg, Singer Andrej
Department of Materials Science and Engineering, Cornell University, Ithaca, NY, USA.
Department of Nanoengineering, University of California San Diego, La Jolla, CA, USA.
Nat Commun. 2024 Dec 30;15(1):10783. doi: 10.1038/s41467-024-55010-6.
Discontinuous solid-solid phase transformations play a pivotal role in determining the properties of rechargeable battery electrodes. By leveraging operando Bragg Coherent Diffractive Imaging (BCDI), we investigate the discontinuous phase transformation in LiNiMnO within an operational Li metal coin cell. Throughout Li-intercalation, we directly observe the nucleation and growth of the Li-rich phase within the initially charged Li-poor phase in a 500 nm particle. Supported by the microelasticity model, the operando imaging unveils an evolution from a curved coherent to a planar semi-coherent interface driven by dislocation dynamics. Our data indicates negligible kinetic limitations from interface propagation impacting the transformation kinetics, even at a discharge rate of C/2 (80 mA/g). This study highlights BCDI's capability to decode complex operando diffraction data, offering exciting opportunities to study nanoscale phase transformations with various stimuli.
非连续的固-固相变在决定可充电电池电极的性能方面起着关键作用。通过利用原位布拉格相干衍射成像（BCDI），我们研究了锂金属硬币电池工作过程中LiNiMnO中的非连续相变。在整个锂嵌入过程中，我们直接观察到了500纳米颗粒中初始充电的贫锂相内富锂相的形核和生长。在微弹性模型的支持下，原位成像揭示了由位错动力学驱动的从弯曲相干界面到平面半相干界面的演变。我们的数据表明，即使在C/2（80 mA/g）的放电速率下，界面传播对转变动力学的动力学限制也可忽略不计。这项研究突出了BCDI解码复杂原位衍射数据的能力，为研究各种刺激下的纳米级相变提供了令人兴奋的机会。
