High Resolution 4D In-Operando Imaging of High Energy Density Battery Electrode Cycling

这项研究结合了先进的成像和诊断技术，解决了用于交通应用的下一代锂电池的先进阳极所面临的挑战。这项研究将建立和利用一个超高空间和时间分辨率的试验台，用于使用纳米级X射线计算机断层扫描(Nano-CT)对电池进行4D(3D时空)术中成像。科学目标是阐明电动汽车和混合动力汽车最有希望的阳极化学物质的失效机理，包括锂金属、锡(锡)和硅(硅)合金化阳极。这项研究的结果可能会对发展锂金属、硅和锡阳极电池技术具有重大好处，这些电池技术有可能在性能和成本上显著超过当前的锂离子电池技术。如果成功，这些电池可以迅速推动电动汽车的采用，以减少排放，提高效率，并增强国内能源安全。PI将支持研究生和本科生的研究经验，将研究与课程相结合，并将工作传达给更广泛的社会。对于锂金属阳极，术中成像实验重点是在标准电解液中高分辨率的枝晶形核和初始生长。成像将利用实验室规模的纳米级分辨率(50 Nm)X射线计算机断层扫描(Nano-CT)仪器。该仪器以Zernike相衬光学为特色，用于对Li等低Z材料进行成像。与透射式或扫描电子显微镜相比，纳米CT的一个关键优势是不需要真空，而且可以使用标准的电解液。此外，纳米CT成像的体积很大，与电极的长度比例相匹配，而不是液体透射电子显微镜细胞的薄片。实验的重点是有控制地引入微/纳米尺度的物理化学特性，并表征它们对有问题的电镀和控制硅和锡阳极合金化的影响。一个关键的目标是确定使电极不稳定并导致树枝晶成核和锂合金颗粒断裂的表面和颗粒特征。合金相形核和扩展的4D图谱将提供对这些体系的稳定相、颗粒/电极形态效应以及颗粒-颗粒相互作用的新的认识。从成像中提取的基本知识然后可以应用于提高这些电极的性能和安全性。

This research addresses the challenges faced with advanced anodes for next generation lithium batteries for transportation applications, using a combination of advanced imaging and diagnostics. The research will establish and utilize an ultra-high spatial and temporal resolution test bed for 4D (3D space + time) in-operando imaging of batteries using nano-scale X-ray computed tomography (nano-CT). The scientific objective is to elucidate the failure mechanisms of the most promising anode chemistries for electric and hybrid vehicles, including Li metal, tin (Sn), and silicon (Si) alloying anodes. The results of this research could have significant benefits to advance battery technologies with Li metal, Si, and Sn anodes, which have the potential to significantly surpass current Li-ion battery technologies in terms of performance and cost. If successful, these batteries could rapidly advance the adoption of electric vehicles for reduced emissions, greater efficiency, and increased domestic energy security. The PI will support the research experiences of graduate and undergraduate students, integrate the research with courses, and communicate the work to the broader community.For Li metal anodes, the in-operando imaging experiments are focused on dendrite nucleation and initial growth at high resolution in standard electrolytes. The imaging will utilize the laboratory-scale nano-scale resolution (50 nm) X-ray computed tomography (nano-CT) instrument. The instrument features Zernike phase contrast optics for imaging low Z materials like Li. A key advantage of nano-CT versus transmission or scanning electron microscopy is there is no need for vacuum and standard electrolytes can be used. In addition, the nano-CT images large volumes that match electrode length scales rather than the thin slices of liquid TEM cells. The experiments focus on the controlled introduction of micro/nano-scale physical and chemical features and characterizing their impact on problematic electroplating and the control of alloying in Si and Sn anodes. A key goal is to identify the surface and particle features that destabilize electrodes and yield dendrite nucleation and Li-alloying particle fracture. The 4D mapping of alloy phase nucleation and propagation will offer new insight into the stable phases of those systems, the particle/electrode morphology effects, and particle-particle interactions. The fundamental knowledge extracted from this imaging can then be applied to advancing the performance and safety of these electrodes.