In situ construction of ultra-stable zincophilic sodium alginate artificial interface layer for dendrite-free anode in aqueous zinc-ion batteries

This study introduces a remarkable approach to tackle the issues of cycle durability and dendrite expansion in aqueous zinc-ion batteries (AZIBs). Through the in-situ complexation of Sodium Alginate (SA) sourced from natural origins onto the zinc anode's interface, we adeptly engineered a stable interface for the zinc anode. In this process, the negatively charged carboxyl groups in SA coordinate with the zinc ions center, achieving stable electrode interface chemistry and uniform zinc ions flow. The in-situ fabricated metal-complex interface on zinc anode, dubbed SA@Zn, not only offers rapid ion adsorption sites and low interfacial resistance but also, based on calculations using Density Functional Theory (DFT), exposes more (002) crystal planes on SA-treated zinc foil, resulting in superior electrochemical stability. When immersed in a 2 mol zinc sulfate electrolyte, the zinc anode, which had been processed with SA, demonstrated remarkable stability, enduring cycling tests for over 1200 h at a current density of 1 mA cm⁻². This research provides a novel technological foundation that advances the advancement of AZIBs, showcasing their immense capacity for energy storage uses and enhancing their viability and applicability in real-life scenarios.