Highly reversible Zn anode by ion flow regulation and micro-corrosion zone division

Aqueous zinc-ion batteries (AZIBs) have been receiving continuous attention as candidates for the next generation of safe batteries, but the poor reversibility of the Zn anode limits their further development. In recent years, researchers have been obsessed with modifying the surface of the Zn anode and adjusting the solvation structure of Zn ²⁺ to address these challenges. Here, we present a novel strategy to improve the reversibility of the Zn anode by simultaneously regulating the zinc ion flow and dividing micro-corrosion zones on the surface of the Zn anode, thereby manipulating the deposition behavior of Zn ²⁺ and relieving the corrosion of the Zn anode. This approach exploits the keto-enol tautomerism of α-acetyl-γ-butyrolactone (ABL) to develop a specifically designed additive: Zn ²⁺ coordinated α-acetyl-γ-butyrolactone complex (ZnABL). With this innovative additive, the Zn anodes showed excellent reversibility: the Zn||Zn symmetric cell achieved a long cycle life of 7780 h (about 11 months) and the Coulombic Efficiency averagely reached a high value of 99.87 %. Furthermore, the Zn||Zn _0.25 V ₂ O ₅ ·H ₂ O near-ampere-hour pouch cell, featuring a high areal capacity of 7.9 mAh cm ^-2 , achieved an energy density of 106.17 Wh L ^-1 and sustained more than 350 cycles. The success of ZnABL in modulating the zinc ion flow and compartmentalizing the micro-corrosion zone provides a novel option for the reversibility improvement of Zn anodes.