Toward Planar and Dendrite-Free Zn Electrodepositions by Regulating Sn-Crystal Textured Surface

Abstract

The propensity of Zn-metal anodes to form non-uniform or dendritic electrodeposits is bound up with the nature of the electrode surface. However, the effect of surface structure on the inherent nucleation and deposition of Zn is not yet well understood. Here, the surface structure of a Zn-metal anode is reconstructed with Sn-crystal textures via a facile chemical displacement reaction. Compared to the bare Zn, the high-affinity Zn binding sites of Sn afford lower deposition energy barrier, which promotes deposition kinetics. What is more, a Sn-textured surface with moderate Zn affinity but high average surface energy ensures a better wettability from the deposits, leading to the lateral growth of Zn crystals. The resultant Sn-textured Zn-metal anode exhibits an extremely low voltage hysteresis of 20 mV and achieves a prolonged cycling stability over 500 h cycles without dendrite formation. This work provides new insights into the crystal-texture-dependent Zn electrodeposition process and offers direction for direct surface texturing to better stabilize Zn-metal anodes with improved reversibility.

Keywords: Zn-ion batteries; crystal textures; dendrite-free electrodeposition; surface energy; surface structures.