Capacity retention of anode-free cells, in which the cathode's lithium was the sole lithium source, was studied. These cells fail by depletion of their limited amount of cycling lithium, unlike cells with lithium foil anodes in which the buildup of an insulating, dead lithium layer on the anodes causes failure. The electrolyte dependence of the deposition morphologies was also studied optically in a symmetrical cell built with lithium electrodes. After passage of 28 mAh cm −2 , dendrite-free deposits were observed in a concentrated LiNO 3 electrolyte. SEI characterization revealed that this LiNO 3 concentrated electrolyte formed a Li 2 O enriched and organic polymer depleted interphase.

Imaging of lithium electrodepositions revealed that in the absence of a compressed porous separator, achieved via a plastic washer, dendrite-free lithium was deposited from glyme solutions of 1 M LiNO3.

Sodium–potassium alloys have recently been proposed as anode materials for liquid metal batteries because they can form a liquid phase at room temperature for a wide range of compositions. In this work, the electrodeposition morphology of this NaK alloy is revealed through in situ optical imaging. We report that the NaK alloy deposits dendritically akin to solid sodium anodes in liquid organic electrolytes. However, when sodium is deposited on a potassium-rich alloy, dendrite formation is greatly mitigated but not prevented.