Dual-regulation of solvation structure and interfacial chemistry for ultra-stable zinc metal anodes

The development of aqueous zinc-ion batteries (AZIBs) is severely restricted by the instability of Zn metal anodes, primarily caused by unchecked Zn dendrite proliferation and parasitic reactions involving active water molecules. These issues are fundamentally associated with the solvation structure of Zn²⁺ ions and the interfacial characteristics between the electrode and electrolyte. Here, we introduce 1-(2-chloroethyl)piperidine hydrochloride (CPH) as a multifunctional electrolyte additive and proposed a novel dual-regulation strategy. Comprehensive characterizations and theoretical calculations reveal that CPH modulates the solvation structure of Zn²⁺ via Cl^- and reconstructs the electrode/electrolyte interface through its adsorption capability, thereby effectively protecting the Zn anode. As a result, the Zn||Zn symmetric cell with CPH achieves excellent cycling stability, operating for over 2900 h at 5 mA cm^-2 and 1 mAh cm^-2. Additionally, the Zn//VO₂ full cell demonstrates significantly enhanced rate performance and cycling durability, retaining 90.15 % of its capacity after 1000 cycles. This work provides significant insights into collaborative electrolyte design for advancing sustainable energy storage systems.