Røe Ingeborg Treu, Selbach Sverre M, Schnell Sondre Kvalvåg
Department of Materials Science and Engineering, Norwegian University of Science and Technology, NTNU, NO-7491 Trondheim, Norway.
J Phys Chem Lett. 2020 Apr 16;11(8):2891-2895. doi: 10.1021/acs.jpclett.0c00819. Epub 2020 Mar 30.
Dendrite formation on Li metal anodes hinders commercialization of more energy-dense rechargeable batteries. Here, we use the (MEB) for surface transport as a descriptor for dendrite nucleation and compare Li to Mg. Density functional theory calculations show that the MEB for the hexagonal close-packed structure is 40 and 270 meV lower than that of the body-centered cubic structure for Li and Mg, respectively. This is suggested as a reason why Mg surfaces are less prone to form dendrites than Li. We show that the close-packed facets exhibit lower MEBs because of smaller changes in atomic coordination during migration and thereby less surface distortion.
锂金属阳极上的枝晶形成阻碍了能量密度更高的可充电电池的商业化。在此，我们使用用于表面传输的平均电场（MEB）作为枝晶成核的描述符，并将锂与镁进行比较。密度泛函理论计算表明，六方密堆积结构的MEB分别比锂和镁的体心立方结构的MEB低40和270毫电子伏特。这被认为是镁表面比锂表面更不易形成枝晶的原因。我们表明，由于迁移过程中原子配位的变化较小，密排面表现出较低的MEB，从而表面畸变较小。
