Establishing a C,N,F-Solid Electrolyte Interphase and Poor-H₂O Solvation Structure for Stabilizing Zinc Anodes

Aqueous zinc-ion batteries are an attractive type of energy storage device but face issues of dendrite growth and side reactions on the Zn anode interface. Here, a high-electronegativity C,N,F-solid electrolyte interphase (SEI) is built using a 2-fluoropyridine electrolyte additive to stabilize the Zn anode. Relying on the high electronegativity of element F, the interaction between the SEI and Zn anode is enhanced, and a robust SEI is produced. This robust high-electronegativity SEI induces Zn²⁺ to form homogeneous deposition without dendrites and repels anions away from Zn anode to impede side reactions over long-term cycling. Meanwhile, a poor-H₂O solvation structure established by 2-fluoropyridine reduces the H₂O content on the Zn anode interface to slow hydrogen evolution. Benefiting from the robust SEI and poor-H₂O solvation structure, a long-term stable Zn anode is achieved. Therefore, the Zn-ion battery exhibits higher plating/stripping reversibility and longer cycling performance.