Regulation of Zinc Deposition by In Situ Formed Liquid Metal Interface for Dendrite‐Free Zinc Metal Anodes

Uncontrolled dendrite growth and side reaction challenges of zinc anode are regulated by a liquid metal gallium interface, which is in situ formed on carbon paper. The conductive liquid gallium layer lowers the nucleation energy barrier of zinc and enables uniform electric field and ion flux for zinc deposition. These results pave a novel way of interface regulation for dendrite-free zinc anode.

Abstract

Uncontrolled dendrite growth, hydrogen evolution and corrosion challenges associated with zinc (Zn) anodes significantly restrict the practical application of zinc batteries. Herein, a liquid metal gallium (Ga) interface is in situ formed on carbon paper (CP) by electrochemical co-deposition to construct a dendrite-free Zn-Ga@CP composite electrode which can regulate the transport and chemistry of Zn deposition at the electrode/electrolyte interface. Notably, the concurrent reduction of Zn²⁺ and Ga³⁺ on carbon paper results in the formation of a self-supporting Zn electrode with 3D interpenetrating structure of Zn and Ga. Compared to zinc foil electrodes, the highly conductive liquid Ga layer lowers the nucleation energy barrier of Zn promotes the homogeneity of the electric field and ion flux, and induces uniform deposition of Zn. In addition, the low chemical activity of liquid Ga prevents a high rate of hydrogen evolution reaction and associated parasitic reactions. As a result, the Zn-Ga@CP symmetric cell delivers stable cycling of >350 h at a discharge depth of 23.3% and ultra-low voltage hysteresis. Moreover, the coin-type and pouch-type full cells exhibit excellent durability and good mechanical stability. This work provides a novel interface regulation strategy for achieving high-performance dendrite-free anode in Zn metal batteries.