Martín-Yerga Daniel, Xu Xiangdong, Valavanis Dimitrios, West Geoff, Walker Marc, Unwin Patrick R
Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K.
Department of Chemistry, Nanoscience Center, University of Jyväskylä, Jyväskylä 40100, Finland.
ACS Nano. 2024 Aug 27;18(34):23032-23046. doi: 10.1021/acsnano.4c05001. Epub 2024 Aug 13.
The development of Li metal batteries requires a detailed understanding of complex nucleation and growth processes during electrodeposition. techniques offer a framework to study these phenomena by visualizing structural dynamics that can inform the design of uniform plating morphologies. Herein, we combine scanning electrochemical cell microscopy (SECCM) with interference reflection microscopy (IRM) for a comprehensive investigation of Li nucleation and growth on lithiophilic thin-film gold electrodes. This multimicroscopy approach enables nanoscale spatiotemporal monitoring of Li plating and stripping, along with high-throughput capabilities for screening experimental conditions. We reveal the accumulation of inactive Li nanoparticles in specific electrode regions, yet these regions remain functional in subsequent plating cycles, suggesting that growth does not preferentially occur from particle tips. Optical-electrochemical correlations enabled nanoscale mapping of Coulombic Efficiency (), showing that regions prone to inactive Li accumulation require more cycles to achieve higher . We demonstrate that electrochemical nucleation time () is a lagging indicator of nucleation and introduce an optical method to determine at earlier stages with nanoscale resolution. Plating at higher current densities yielded smaller Li nanoparticles and increased areal density, and was not affected by heterogeneous topographical features, being potentially beneficial to achieve a more uniform plating at longer time scales. These results enhance the understanding of Li plating on lithiophilic surfaces and offer promising strategies for uniform nucleation and growth. Our multimicroscopy approach has broad applicability to study nanoscale metal plating and stripping phenomena, with relevance in the battery and electroplating fields.
锂金属电池的发展需要详细了解电沉积过程中复杂的成核和生长过程。相关技术通过可视化结构动力学提供了一个研究这些现象的框架，这些动力学可以为均匀镀层形态的设计提供信息。在此，我们将扫描电化学池显微镜（SECCM）与干涉反射显微镜（IRM）相结合，以全面研究锂在亲锂性薄膜金电极上的成核和生长。这种多显微镜方法能够对锂的电镀和剥离进行纳米级的时空监测，同时具有筛选实验条件的高通量能力。我们揭示了特定电极区域中无活性锂纳米颗粒的积累，但这些区域在随后的电镀循环中仍保持功能，这表明生长并非优先从颗粒尖端发生。光电化学相关性实现了库仑效率（）的纳米级映射，表明易于积累无活性锂的区域需要更多循环才能实现更高的。我们证明电化学成核时间（）是成核的一个滞后指标，并引入了一种光学方法来在更早阶段以纳米级分辨率确定。在更高电流密度下进行电镀会产生更小的锂纳米颗粒并增加面密度，并且不受异质地形特征的影响，这可能有利于在更长的时间尺度上实现更均匀的电镀。这些结果加深了对锂在亲锂表面上电镀的理解，并为均匀成核和生长提供了有前景的策略。我们的多显微镜方法在研究纳米级金属电镀和剥离现象方面具有广泛的适用性，与电池和电镀领域相关。
