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 microsco py (SPoM) were conducted to investigate the surface condition of the electr odeposited lithium on nickel substrate. Distribution of surface potential c orresponds to that of thickness or chemical composition of the surface film on lithium metal. The fine lithium particles deposited in the nonaqueous e lectrolyte containing HF showed no significant distribution of sm-face pote ntial. This means that the highly uniform surface film was formed on these lithium particles. Therefore, it can be said the surface modification of li thium surface with HF leads to the formation of uniform surface films on li thium deposits. On the other hand, prominent distribution of surface potent ial was observed for the lithium metal after dissolution and deposition cyc les in the electrolyte containing HF and the dendritic lithium at the initi al stage of growth. Consequently, these results confirm that the inhomogene ity of the surface film on lithium metal promotes the formation of dendriti c lithium.