Designing Cost-Effective Molecule-Substitution-Induced Anchoring Additives to Enable Stable Zinc-Ion Batteries

Aqueous zinc-ion batteries (AZIBs) are considered among the most promising energy storage systems because of their low cost, high safety, and high theoretical capacity. However, challenges including Zn2+ desolvation, side reactions, and dendritic growth significantly hinder their rate capability and cycling stability. In this study, we propose a molecule-substitution-induced anchoring strategy by introducing kojic acid molecules with carbon-based (C═O) and hydroxyl (C–OH) groups to modulate the Zn2+ solvation structure, lower the desolvation activation energy, and effectively suppress undesirable side reactions. More importantly, its pyranone ring (C–O–C) can anchor onto the Zn surface to form an adsorption layer, which induces the uniform deposition of Zn2+ ions and consequently suppresses dendrite formation. At a current density of 1 mA cm–2 and an areal capacity of 1 mAh cm–2, the symmetric cell demonstrated an ultralong lifespan of 2800 h and a high Coulombic efficiency of 99.72%. Furthermore, the assembled Zn||δ-MnO2 full cell had a capacity retention of 95% after 1500 cycles at 3 A g–1. Even at an elevated temperature of 50 °C, the cell retained a capacity of 197.9 mAh g–1 after 200 cycles.