Zhu Maogen, Xu Kangli, Li Danying, Xu Tao, Sun Wei, Zhu Yongchun, Qian Yitai
Department of Chemsistry and National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China.
ACS Appl Mater Interfaces. 2020 Aug 26;12(34):38098-38105. doi: 10.1021/acsami.0c09430. Epub 2020 Aug 13.
Lithium metal anodes are considered as promising candidates for next-generation high-energy-density batteries. However, the dendrite formation of Li metal anodes during charge-discharge results in some serious issues. Herein, we show a simple way to flatten the Li metal deposition surface on Ag-modified Cu foil using a spherical island model. In this model, Ag nuclei induce the deposition of Li atoms with low nucleation potentials at the initial heterogeneous nucleation stage. Then, Li homogeneously grows around the spherical islands and these regular islands overlap each other and form a flat Li surface. On the bare Cu foil surface, the Li growth behavior is random, and the deposition surface is porous and covered with dendrites. Stable long-term plating/stripping of a symmetric battery over 800 h at 1 mA cm was achieved. Moreover, the super flat Li structure can be achieved by constructing islands into a three-dimensional (3D) current collector using the spherical island model. Benefiting from the spherical island model, Li||LiFePO and Li||O batteries with this 3D anode structure can obtain a stable performance.
锂金属阳极被认为是下一代高能量密度电池的有前景的候选者。然而，锂金属阳极在充放电过程中枝晶的形成会导致一些严重问题。在此，我们展示了一种使用球形岛模型使锂金属在银改性铜箔上的沉积表面变平整的简单方法。在该模型中，银核在初始异质成核阶段诱导具有低成核势的锂原子沉积。然后，锂在球形岛周围均匀生长，并且这些规则的岛相互重叠并形成平坦的锂表面。在裸铜箔表面上，锂的生长行为是随机的，沉积表面是多孔的且覆盖有枝晶。在1 mA cm下实现了对称电池超过800小时的稳定长期电镀/剥离。此外，通过使用球形岛模型将岛构建到三维（3D）集流体中可以实现超平坦的锂结构。受益于球形岛模型，具有这种3D阳极结构的Li||LiFePO和Li||O电池可以获得稳定的性能。
