In-Situ Constructed Antimony-Zinc Alloy Interfacial Layer for Dendrite-Free and Stable Aqueous Zinc-Ion Batteries

Abstract

Aqueous zinc-ion batteries are promising candidates for energy storage due to their inherent safety from aqueous electrolytes, the high theoretical capacity of zinc anodes, and low cost. However, zinc anodes face challenges such as dendrite formation, hydrogen evolution, passivation, and corrosion. To address hydrogen evolution and corrosion, an antimony-zinc alloy interfacial layer (SbZn-Zn) was synthesized in situ on the zinc anode via a one-step method. This layer adheres robustly to the zinc foil surface, resists detachment during cycling, and maintains structural integrity throughout electrochemical processes. The SbZn alloy exhibits strong affinity for Zn²⁺ ions, restricting their two-dimensional diffusion. This promotes rapid and uniform zinc-ion deposition on the anode surface. In symmetric cell tests, the modified anode achieved a cycling lifespan of 1,500 hours at 5 mA cm⁻² and 1 mAh cm⁻², with a low overpotential of 19.5 mV. When paired with an ammonium vanadate cathode, the full cell retained a reversible capacity of 108.5 mAh g⁻¹ after 5,000 cycles at 10 A g⁻¹.

Keywords: Aqueous batteries, zinc metal anode, alloy, interfacial layer, long cycling life