Understanding the structure–activity relationship of additives for durable Zn metal batteries: a case study of aromatic molecules

The practical implementation of aqueous metal batteries faces significant challenges due to detrimental dendrite formation and parasitic side reactions. While numerous studies have explored electrolyte additives to address these issues, the fundamental structure–activity relationship of these additives—particularly regarding their adsorption configurations and their dual functionality in suppressing dendrite growth and corrosion—remains insufficiently understood, especially at low additive concentrations. In this study, we systematically investigated a series of aromatic Lewis base molecules as a study case and discovered that the optimal adsorption configuration, governed by the spatial arrangement of nitrogen (–N) sites, plays a crucial role in simultaneously providing abundant zincophilic sites to facilitate Zn2+ desolvation and guiding uniform Zn nucleation while effectively suppressing hydrogen evolution. This optimized configuration enables exceptional long-term cycling stability in both Zn symmetric cells and Zn||NVO full cells. This work may shed light on the additive design for not only Zn but also other alkaline metal anodes in aqueous energy storage systems.