Isomalt Additive Induced Ultradense Zinc Deposition for Dendrite‐Free and Hydrogen‐Suppressed Aqueous Zinc‐Ion Batteries

Achieving ultradense zinc plating is a key prerequisite for fully exploiting the potential of aqueous zinc metal batteries for high‐energy, large‐scale energy storage. However, realizing such ideal deposition remains a major scientific challenge, severely constrained by interfacial instabilities, including dendrite growth, water‐induced hydrogen evolution reaction (HER), and heterogeneous ion flux. To address these issues, isomalt (denoted as ISO) was introduced as an electroplating solution additive to obtain an optimized zinc anode. During electroplating, ISO molecules selectively adsorbed on the Zn (101) crystal plane, inducing preferential growth of the (101) plane and the formation of a flat, dense zinc anode, which effectively suppressed the HER side reaction and dendrite growth. As a result, the modified zinc anode exhibited a HER overpotential of −1.19 V (vs. SHE) at 5 mA cm ⁻² . Zn//Zn symmetric cell assembled with the constructed anode achieved a stable cycling life of 1800 h at 5 mA cm ⁻² (1 mAh cm ⁻² ), and the Zn//Cu asymmetric cell maintained an average Coulombic efficiency (CE) of 98.7% over 2000 cycles. Furthermore, the Zn//I ₂ full cell demonstrated a high specific capacity retention of 92.6% after 10,000 cycles. To induce the preferred orientation of Zn crystals, this work provides valuable insights and will contribute to the development of high‐performance zinc anodes.