Multidentate polar interactions enable ultralow-dosage electrolyte additives for stabilizing Zn-I₂ batteries

Electrolyte additives typically require high concentrations to achieve efficient activity in stabilizing aqueous Zn-I₂ batteries. Here, we showed that multidentate polar interactions enable effective interfacial regulation at an ultralow additive dosage (1 mM). Using D-glucuronamide as a model additive, cooperative interactions with Zn surfaces and polyiodide species simultaneously stabilize Zn deposition and suppress polyiodide shuttling, enabling 99.93% Coulombic efficiency over 5000 cycles and 92% capacity retention over 10 000 cycles. This work demonstrates a strategy for achieving high interfacial activity without high additive concentration.