Bridging Ligand Chemistry Enabled High‐Performance Zn Metal Anodes in Aqueous Electrolytes

ABSTRACT Organic molecules containing multiple heteroatoms have been reported as effective additives for suppressing Zn dendrites and enhancing Zn anode performance in aqueous batteries. However, the underlying mechanism of these heteroatoms in governing their function and enhancing electrochemical properties is not well understood. Using 2,2'‐bipyrimidine (Bpm) and pyrimidine (Pym) as model additives, it is found that Bpm, as a multi‐dentate ligand, exhibits unique bridging ligand functionality in aqueous electrolytes, compared with Pym as a terminal ligand. By promoting coordination interactions and formation of Zn‐ligand‐Zn structure, multiple heteroatoms in Bpm enable bridging ligand chemistry (BLC), which facilitates reconstruction of solvation structures, remodels electrode‐electrolyte interfaces, promotes uniform Zn deposition, and constrains parasitic side reactions and corrosion. Consequently, Bpm with a concentration of merely 5 mM dramatically improved the electrochemical performance with a sixteen‐fold increase in the cycling lifespan of Zn//Zn symmetric cells at 1.0 and 10.0 mA cm − 2 and a 70.5% capacity retention of Zn//V 2 O 5 full cells after 500 cycles at 2.0 A g −1 . The BLC mechanism is further supported by validation using five selected multi‐heteroatom organic additives. These results offer valuable insights into the rational design and engineering of electrolytes for high‐performance aqueous Zn batteries.