Imaging for Uniformity of Lithium Metal Surface Using Tapping Mode-Atomic Force and Surface Potential Microscopy

Tapping mode-atomic force microscopy (TMAFM) and surface potential microscopy (SPoM) were conducted to investigate the surface condition of the electrodeposited lithium on nickel substrate. Distribution of surface potential corresponds to that of thickness or chemical composition of the surface film on lithium metal. The fine lithium particles deposited in the nonaqueous electrolyte containing HF showed no significant distribution of surface potential. This means that the highly uniform surface film was formed on these lithium particles. Therefore, it can be said the surface modification of lithium surface with HF leads to the formation of uniform surface films on lithium deposits. On the other hand, prominent distribution of surface potential was observed for the lithium metal after dissolution and deposition cycles in the electrolyte containing HF and the dendritic lithium at the initial stage of growth. Consequently, these results confirm that the inhomogeneity of the surface film on lithium metal prom...