A reversible dendrite-free high-areal-capacity lithium metal electrode

Reversible dendrite-free low-areal-capacity lithium metal electrodes have recently been revived, because of their pivotal role in developing beyond lithium ion batteries. However, there have been no reports of reversible dendrite-free high-areal-capacity lithium metal electrodes. Here we report on a strategy to realize unprecedented stable cycling of lithium electrodeposition/stripping with a highly desirable areal-capacity (12 mAh cm −2 ) and exceptional Coulombic efficiency (>99.98%) at high current densities (>5 mA cm −2 ) and ambient temperature using a diluted solvate ionic liquid. The essence of this strategy, that can drastically improve lithium electrodeposition kinetics by cyclic voltammetry premodulation, lies in the tailoring of the top solid-electrolyte interphase layer in a diluted solvate ionic liquid to facilitate a two-dimensional growth mode. We anticipate that this discovery could pave the way for developing reversible dendrite-free metal anodes for sustainable battery chemistries. Despite recent technological advances, it remains challenging to realize reversible high-areal-capacity lithium metal anodes. Here, the authors demonstrate such an anode by tailoring the top solid electrolyte interphase layer.