Dendrite-Free Lithium Deposition with Self-Aligned Columnar Structure in a Carbonate–Ether Mixed Electrolyte

Batteries with lithium metal anodes are promising because of lithium’s high energy density. However, the growth of Li dendrites on the surface of the Li electrode in a liquid electrolyte during cycling reduces the safety and cycle performance of batteries, hindering their commercial application. In this work, we observe for the first time a smooth and dendrite-free Li deposition with a vertically grown, self-aligned, and highly compact columnar structure formed during cycling in a mixed carbonate–ether electrolyte. The stable microsized (∼10 μm in diameter and ∼20 μm in length) Li deposits are aligned in arrays on the surface of the Li electrode. The columnar Li deposits still exhibit a dendrite-free morphology and a compact structure after 200 cycles at a current density of 1 mA/cm² and a 1.5 mAh/cm² cycling capacity in a mixed carbonate–ether electrolyte. This work shows an optimiztic outlook for Li batteries with liquid electrolytes.