Interface Engineering of Flexible Liquid Metal Modulation To Achieve Dendrite-Free Zinc Metal Anodes

Abstract

With low cost and high safety, zinc metal anodes shine brilliantly in aqueous energy storage batteries. However, the devilish growth of dendrites, high reactivity with water molecules, and undesirable side effects hinder their further application. Here, liquid gallium coverage is subtly introduced on the surface of a commercial zinc foil by a simple scraper process aimed at achieving a dendrite free and excellently reversible zinc anode. Practical interfacial engineering inhibits zinc dendrite formation and mitigates hydrogen evolution and side reactions. In addition, thanks to the liquid metal, the wetting behavior of the electrode/electrolyte interface is significantly optimized. Meanwhile, the fluidity of Ga facilitates the construction of locally homogeneous electric fields and ionic flux. As a result, the prepared Zn@Ga anodes exhibit high reversibility, stable cycle life, and outstanding rate capability. Paired with a manganese dioxide cathode, the Zn@Ga||MnO2 full battery achieves an excellent specific capacity (259.9 mAh g–1) and a consistently long cycle life (capacity retention of 89% after 500 cycles). This study brings a novel perspective to realizing high-performance Zn anodes without dendrites.

Structural and Interfacial Engineering Strategies for Constructing Dendrite-Free Zinc Metal Anodes

“…84,85 Several metal substances have been reported to exhibit remarkable capabilities in accelerating Zn deposition kinetics and suppressing Zn dendrite propagation, including silver, 86 gold, 87 copper, 88 cadmium, 89 and gallium. 90 Through a facile metallic replacement reaction, Ag nanoparticles have been coated on the surface of ZMA, which not only serves as nucleation seeds for Zn deposition, but also the resulting AgZn 3 alloys formed during the initial plating cycle exhibit superior Zn affinity, effectively lowering the energy barrier for Zn deposition. 86 The modified ZMA demonstrated a long and stable cyclic performance of over 1700 h with an extremely low overpotential of only 21 mV under 0.25 mA cm −2 .…”

“…For example, by employing a scraper process, Zhang et al designed a ZMA with liquid Ga coating. 90 The liquid Ga with high wettability optimizes the electrode/ electrolyte interfaces and reconstructs the local electric fields and ionic flux. The modified ZMAs showed high reversibility and a stable cyclic performance.…”

“…Metal substances can serve as effective protective layers to mitigate Zn dendrite formation and growth due to their high electrical conductivity and favorable zincophilic properties, thereby promoting fast electron transfer and chemical adsorption of Zn 2+ . , Several metal substances have been reported to exhibit remarkable capabilities in accelerating Zn deposition kinetics and suppressing Zn dendrite propagation, including silver, gold, copper, cadmium, and gallium . Through a facile metallic replacement reaction, Ag nanoparticles have been coated on the surface of ZMA, which not only serves as nucleation seeds for Zn deposition, but also the resulting AgZn 3 alloys formed during the initial plating cycle exhibit superior Zn affinity, effectively lowering the energy barrier for Zn deposition .…”

“…Besides solid-state metal substances, liquid metal substances have shown self-healing properties, that can substantially improve the integrity of ZMAs. For example, by employing a scraper process, Zhang et al designed a ZMA with liquid Ga coating . The liquid Ga with high wettability optimizes the electrode/electrolyte interfaces and reconstructs the local electric fields and ionic flux.…”