Aromatic additives with designed functions ameliorating chemo-mechanical reliability for zinc-ion batteries

Zn-ion batteries (ZIBs) emerge as potential candidates for scalable energy storage due to their advantages of high safety and excellent performance. However, the implementation of zinc-metal anode faces challenges, such as dendrite growth, hydrogen evolution, and by-product formation. Herein, we explore an archive of aromatic molecules with different ligands, encompassing carboxyl, hydroxyl, aldehyde, and sulfonate groups as electrolyte additives. Testing results provided an insight into the molecular structure, charge state, and chelating groups on the chemo-mechanical stability of ZIBs. The calculation results reveal that carboxyl and hydroxyl ligands allow stronger chemisorption on metallic Zn. Chelating properties of salicylate and catecholate ligands facilitate effi-cient solvation based on additive-Zn2+ coordination. The aldehyde and sulfonate ligands promote a textural growth of the (002) plane attributed to their lipophilic properties. The sulfonate-based molecules offer collective benefits owing to their large polar surface and designed textural deposits. The deposition of additive-Zn2+ complexes yields a robust layer with concentration gradients, thus hindering the crack propagation induced by oxidative stress. Zn//Zn stability tests show that sulfonate additives improved a lifetime from 50 to 3000 cycles at 2 mA cm-2 and 1 mAh cm-2. The results open a new strategy to develop and optimize advanced electrolytes for aqueous energy storage.

Automated summary

This study explores the use of aromatic molecules with different ligands as electrolyte additives to improve the chemo-mechanical stability and performance of Zn-ion batteries (ZIBs). Carboxyl and hydroxyl ligands show stronger chemisorption on metallic Zn, while salicylate and catecholate ligands promote efficient solvation based on additive-Zn2+ coordination. Aldehyde and sulfonate ligands enhance the textural growth of the (002) plane due to their lipophilic properties. Sulfonate-based molecules offer the best deposition effect, forming a robust layer with concentration gradients that hinder crack propagation induced by oxidative stress. The addition of sulfonate additives improves the lifetime of Zn-ion batteries from 50 to 3000 cycles. These findings provide a new strategy for the development and optimization of advanced electrolytes for aqueous energy storage.