Multiple Regulation of Electrolyte with Trace Amounts of Sodium Dehydroacetate Additives Enables High‐Performance Aqueous Zinc‐Ion Batteries
L.L. Li, Zeqi Liu, Geliang Dai, Yong Xia, Lijian Xu, Aokui Sun, Jingjing Du
Abstract
Abstract Rechargeable aqueous zinc‐ion batteries (AZIBs) draw much attention for low cost and high safety. However, hydrogen evolution reaction (HER) and uneven Zn 2+ deposition shorten lifespan, hampering commercial use. In this study, sodium dehydroacetate (SD) containing carbonyl and keto‐carbonyl is introduced as multifunctional electrolyte additives, which effectively modifies the solvent shell structure, achieving a Zn 2+ transference number of up to 0.72. Acting as a hydrogen bond acceptor, SD disrupts the water network structure, thereby increasing the HER overpotential by 22 mV and the corrosion potential by 9 mV. The polar functional groups in SD can reversibly capture H⁺ ions and dynamically neutralize OH⁻ ions, maintaining interfacial pH balance on the zinc anode and suppressing HER. Notably, SD not only alters the electrolyte's kinetic but also induces uniform Zn 2+ deposition along the (002) plane, inhibiting dendrite growth and minimizing side reactions. This phenomenon is demonstrated in both symmetric and full‐cell configurations. The Zn//Zn symmetric cell achieves an ultra‐long cycling lifespan of 2800 hours at 5 mA cm⁻ 2 , and the Zn//VO 2 full battery maintains a capacity retention rate of 73.09% after 2000 cycles with a high average coulombic efficiency of 99.98%, underscoring the effectiveness of this electrolyte additive in enhancing battery performance.