"Dead" Lithium: Interface Evolution and Characterization

During stripping of lithium metal anode, some fraction of lithium becomes detached from the lithium anode. This remnant lithium is electrochemically inactive and is called “dead” lithium. This leads to irreversible loss of capacity and lowers the Coulombic efficiency of the battery. The presence of dead lithium also affects the transport of lithium ions in the electrolyte which can potentially alter the conditions for plating during subsequent cycling. The aim of this work is to identify the dominant mechanisms responsible for the formation of dead lithium as well as quantify the amount of dead lithium. Mesoscale modeling along with experimental corroboration to probe the evolution of the interface between lithium anode and liquid electrolyte during discharging will be presented. The effect of ionic diffusion in electrolyte, surface diffusion of lithium and electrochemical reaction rate kinetics are considered. Figure 1