Multifunctional Yttrium Acetate Additive Enables Simultaneous pH Stabilization and Deposition Regulation for Highly Durable Aqueous Zinc‐Ion Batteries

Aqueous zinc‐ion batteries (AZIBs) are promising for large‐scale energy storage due to their safety, low cost, and high capacity, but their practical application is hindered by zinc dendrite growth, hydrogen evolution, corrosion, and pH instability. Herein, yttrium acetate (Y(Ac) 3 ) is introduced as a multifunctional electrolyte additive to simultaneously regulate interfacial chemistry and zinc deposition behavior. Ac − suppresses water‐induced side reactions by disrupting the hydrogen‐bond network of water, while the HAc/Ac − buffer system stabilizes the interfacial pH, enabling Y 3+ to fully exert its electrostatic shielding function. In turn, the electrostatic shielding of Y 3+ suppresses the non‐uniform deposition caused by the tip effect, creating favorable conditions for the ordered adsorption of Ac − , thereby promoting Zn(002)‐oriented deposition and uniform nucleation. Benefiting from these synergistic effects, Zn||Zn symmetric cells with Y(Ac) 3 additive achieve exceptional cycling stability of 5200 h at 2 mA cm −2 /1 mAh cm −2 . Zn||Cu cells deliver an ultrahigh Coulombic efficiency of 99.8% over 6500 cycles at 5 mA cm −2 /1 mAh cm −2 . Furthermore, Zn||NVO full cells exhibit 86.2% capacity retention after 2000 cycles at 6 A g −1 . This work demonstrates that Y(Ac) 3 is an effective pH‐stabilizing and deposition‐regulating additive, offering a practical strategy for constructing highly durable AZIBs.