Unlocking High-Performance Zinc Batteries via Haloacetamide-Regulated Nucleation and Interface Chemistry

Abstract

Lithium-ion batteries dominate the secondary battery market but are increasingly challenged by concerns over safety, sustainability, and critical material dependency. Aqueous zinc metal batteries (AZMBs) offer a compelling alternative for safe, low-cost, and environmentally friendly energy storage. However, their practical deployment is hindered by dendrite formation, hydrogen evolution, and interfacial instability. Here, we introduce haloacetamides as a new class of electrolyte additives that regulate zinc interfacial chemistry at the molecular level. Specifically, iodoacetamide modulates Zn²⁺ solvation and surface reactivity via dual coordination with water molecules and Zn²⁺ ions, enabling precise control over nucleation and deposition pathways. This leads to compact, dendrite-free Zn morphology while significantly suppressing hydrogen evolution and corrosion. Notably, iodoacetamide lowers the overpotential from 30 mV to 19 mV, indicating improved reversibility of Zn plating/stripping. As a result, symmetric Zn‖Zn cells demonstrate outstanding cycling stability exceeding 2000 h, and full cells maintain over 82% Coulombic efficiency for more than 1500 cycles. The additive also enhances highrate capability by facilitating Zn²⁺ transport and interfacial uniformity. This study presents a previously unexplored strategy for tuning Zn interfacial behavior through halogenated molecular design, representing a paradigm shift in aqueous battery additive development. Our findings highlight haloacetamides as a powerful platform for interphase engineering toward durable, high performance AZMBs.