Electrolyte Chemistry in 3D Metal Oxide Nanorod Arrays Deciphers Lithium Dendrite-Free Plating/Stripping Behaviors for High-Performance Lithium Batteries

Abstract

Lithium dendrite-free deposition is crucial to stabilizing lithium batteries, where the three-dimensional (3D) metal oxide nanoarrays demonstrate an impressive capability to suppress dendrite due to the spatial effect. Herein, we introduce a new insight into the ameliorated lithium plating process on 3D nanoarrays. As a paradigm, novel 3D Cu₂O and Cu nanorod arrays were <i>in situ</i> designed on copper foil. We find that the dendrite and electrolyte decomposition can be mitigated effectively by Cu₂O nanoarrays, while the battery failed fast when the Cu nanoarrays were used. We show that Li₂O (i.e., formed in the lithiation of Cu₂O) is critical to stabilizing the electrolyte; otherwise, the electrolyte would be decomposed seriously. Our viewpoint is further proved when we revisit the metal (oxide) nanoarrays reported before. Thus, we discovered the importance of electrolyte stability as a precondition for nanoarrays to suppress dendrite and/or achieve a reversible lithium plating/stripping for high-performance lithium batteries.